Advanced Characterization Method
CLUB A
Monday, July 22 2013, 10:30 am - 12:00 pm
Chair:

Pam Thomas
University of Warwick

ISAF3-A1-1 ____________________________________________________________________________________________________________________

Recent progress in dielectric and light scattering spectroscopy offerroelectric soft modes
Jan Petzelt, Elena Buixaderas, Tetyana Ostapchuk, Dmitry Nuzhnyy, Volodymyr Skoromets, Veronica
Goian, Viktor Bovtun, Ivan Gregora, Christelle Kadlec, Filip Kadlec, Stanislav Kamba, Petr Kuzel, Jiri
HlinkaDepartment of Dielectrics, Institute of Physics, Academy of Sciences of the Czech Republic Na
Slovance 2, 18221 Praha 8, Czech Republic
Email: petzelt@fzu.cz
Recent results on ferroelectric soft modes using infrared (IR), time-domain THz and microwave (MW)dielectric spectroscopies as well as Raman and hyper-Raman spectroscopies on single crystals, ceramics
and thin films are summarized. In particular, new results obtained on classical perovskite ferroelectrics
BaTiO3 (BTO) single crystals and ceramics, SrTiO3 (STO) films, PbTiO3 (PTO) and PbZrO3 (PZO)
single crystals, (Ba,Sr)TiO3 (BST), (Pb,Zr)TiO3 (PZT), (Ba,Zr)TiO3 (BZT) and (K,Na)NbO3 (KNN)
solid solutions, and PbMg1/3Nb2/3O3 (PMN) single crystals are emphasized, but also other structure
types, as Ruddlesden-Popper phases derived from STO structure and GeTe films are mentioned. The
samples for our studies are obtained from several collaborating laboratories.
In the case of BST, the dielectric response is discussed from the point of view of coupled soft andcentral mode model in the whole composition range and BTO is shown to be the most anharmonic
system1. The same model approach is successfully applied to tensile strained epitaxial thin STO films on
DyScO3 substrates, which exhibit ferroelectric transition near room temperature; the important impact of
Sr stoichiometry on their properties is also studied and discussed. Similar features are revealed in the
dynamics of KNN ceramics2 and in PZT in a broad composition range around the morphotropic phaseboundary3. In the case of BZT ceramics, the dynamics of both the relaxor and diffuse ferroelectric
behavior is studied, consisting of strong softening of an overdamped central-mode component from THz
down to GHz range and by almost no phonon softening4. In classical relaxor single crystal PMN, thehyper-Raman data reveal a clear splitting of the soft mode in a broad temperature range due to the local
symmetry breaking5, appearing along with the well-known MW and lower-frequency central-mode typedispersion.
On the other hand, the new hyper-Raman data on paraelectric PTO and IR data on paraelectric PZO
single crystals indicate a negligible role of the central mode6. In the antiferroelectric PZO, IR and
Raman data show several anomalous low-frequency modes for all orthorhombic symmetry types, which
are discussed in terms of the recent understanding of the complex phase transition. In conducting thin
GeTe films no significant phonon softening is detected; instead a critical THz relaxation is observed in
the paraelectric phase with strength comparable to that of the free carrier absorption7.

1

J. Weerasinghe et al., MRS Com., doi 10.1557/mrc.2013.5.
E. Buixaderas et al., J. Appl. Phys. 107, 014111 (2010).
3
E. Buixaderas et al., Phys. Rev. B 84, 184302 (2011).
4
D. Nuzhnyy et al., Phys. Rev. B 86, 014106 (2012).
5
A. Al-Zein et al., Phys. Rev. Lett. 105, 017601 (2010).
6
J. Hlinka et al., Phys. Rev. B 87, 064101 (2013).
7
F. Kadlec et al., Phys. Rev. B 84, 205209 (2011).
2

ISAF3-A1-2 ____________________________________________________________________________________________________________________A new method of dielectric characterization in the microwave
range for tunable high-k ferroelectric thin films
Kevin Nadaud1, Raphaël Renoud1, Hartmut W. Gundel1, Caroline Borderon1, Raphaël Gillard2
1

IETR, University of Nantes, Nantes, France
2
IETR, INSA of Rennes, Rennes, France
E-mail: kevin.nadaud@univ-nantes.fr

Ferroelectric thin films are widely studied for its non constant dielectric permittivity which allows
realization of electrically tunable components and devices such as microwave filters, reflectarray
antennas, resonators or phase shifters. Depending on the component architecture, the film has to beelaborated either on a conducting electrode or on an insulating substrate. As thin film synthesis, andhence the dielectric properties, strongly depend on the substrate’s crystalline structure, it is important tocharacterize using the same topology as this of the final component.
The method proposed allows measuring the complex permittivity of a ferroelectric thin film in the
microwave range using CoPlanar Waveguide (CPW) technology. MIM (Metal Insulator Metal) topology
would not be appropriate for the foreseen application (a reconfigurable reflect array cell). Elaboration of
the ferroelectric thin film is reported elsewhere8. Most characterization methods relying on CPW arebased on propagation constant or effective permittivity measurements. In the case of high-k thin films,
however, the obtained accuracy is usually poor because the film permittivity does not have a highinfluence on the effective overall permittivity which also includes the contribution of the thick substrate(of relatively low permittivity).
In the present case, we propose a topology which consists of two CPW transmission lines separated by agap (Fig. 1). In order to determine the gap-capacitance, a TRL (Thru, Reflect, Line) calibration method
is used for the de-embedding of the lines. The permittivity of the thin film can be extracted by full wave
simulation or with a mathematical model based on conformal mapping such as in Vendik’s et al. work9that does not use CPW technology. In our case, however, the capacitance also strongly depends on the
ferroelectric permittivity because the gap in the center line is very narrow.

(a)

(b)

Fig. 1: Illustration of the measuring circuit. Top view (a) of the capacity between two coplanar transmission lines
and side view (b) of the ferroelectric thin film deposed on an alumina substrate.

8

C. Borderon, D. Averty, R. Seveno, H.W. Gundel, "Influence of the morphology of Barium Strontium Titanate thin films on the
ferroelectric and dielectric properties", Integrated Ferroelectrics 97 (2008) 12-19
9O. G. Vendik, S. P. Zubko, and M. A. Nikol’ski "Modeling and calculation of the capacitance of a planar capacitor containing aferroelectric thin film" J. Tech. Phy 44 (1999) 349-355

ISAF3-A1-3 ____________________________________________________________________________________________________________________

Central mode in perovskite ferroelectrics: terahertz spectroscopy
and molecular dynamics simulations
P. Kužel1, T. Ostapchuk1, C. Kadlec1, J. Weerasinghe2, L. Bellaiche2 and J. Hlinka1
12Institute of Physics ASCR, Na Slovance 2, Prague, 182 21, Czech Republic
Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
Email: kuzelp@fzu.cz

Two limiting cases of structural phase transitions are often distinguished: displacive and order-disordertypes. In the displacive case, the equilibrium positions of atoms or ions in the crystal correspond to theiraverage positions. The phase transition is triggered by a change of these positions related to the freezingof a low-frequency phonon mode (called “soft mode”, SM). The order-disorder case involves partiallyoccupied sites given by the potential minima (disorder) and the transition is connected to the symmetry
breaking of their spatial distribution (ordering): this is connected to an excitation of the relaxation type(called “central mode”, CM). These excitations are observed by terahertz spectroscopy in ferroelectric
perovskite oxides like (Ba,Sr)TiO3 or K(Ta,Nb)O3 and they often coexist even in the paraelectric phases
and couple to each other10,11. The complex dielectric function () in the terahertz range then can beusually described by 02  ,(1)
02   2  i   2 1  i /  
where 0, 0,  are the plasma frequency, oscillator frequency and damping constant of the SM,
respectively;  is the bare relaxation frequency of the CM and  is the coupling constant.
   

The experiments can be confronted with molecular dynamics calculations based on an effective
Hamiltonian with parameters derived from first principles. The dynamical degrees of freedom consist of
inhomogeneous and homogeneous strain variables and of so called “local soft modes” corresponding tolocal (within a unit cell) displacements of atoms with the SM eigenvector1,12. These degrees of freedom
are sufficient to explain that in the studied perovskites the CM suddenly appears in the spectra well
above the ferroelectric phase transition. The coexistence of the two spectral features is then an intrinsic
property of these materials and a consequence of a complex anharmonic form of the soft mode effective
potential.
In this contribution we will compare experimental terahertz dielectric spectra on BaxSr1-xTiO3 (BST)
system with molecular dynamics simulations. The temperature trends of the SM and CM behavior are
investigated in the paraelectric phase (T > TC). A transition is observed between high-temperature
spectra (T > TCM) described by a simple damped harmonic oscillator (SM) and a low-temperature
behavior (T < TCM) where the spectra fit to the coupled SM-CM model (1). The CM is understood as athermally activated process of hopping between quasi-stable off-center Ti ionic positions described by
Arrhenius-type temperature dependence3. This thermal activation process is at the origin of the changeof the regime between fast and slow relaxation dynamics which then appears almost as a phase transitionin the spectra.

10

J. Hlinka et al., Phys. Rev. Lett., vol. 101, 167402, 2008.
C. Kadlec et al., Phys. Rev. B, vol. 80, 174116, 2009; V. Skoromets et al., Appl. Phys. Lett., vol. 99, 052908, 2011.
12
J. Weerasinghe et al., MRS Communications, available online February 2013. doi:10.1557/mrc.2013.5.
11

ISAF3-A1-4 ____________________________________________________________________________________________________________________

Elastic Anomalies in Ferroelectric Ceramics: Pb(Mg1/3Nb2/3)O3 as
Elastic Relaxor, Octahedral Tilts in Tetragonal Pb(Zr,Ti)O3 andMagneto-elastic Coupling in BiFeO3
Hana Ursic1,2, Tadej Rojac1,2, Li Jin (靳立) 3, Dragan Damjanovic4
1

Electronic Ceramics Department, Jozef Stefan Institute, Ljubljana, Slovenia
2
CoE NAMASTE, Ljubljana, Slovenia
3
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education& International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, China
4
Ceramics Laboratory, Swiss Federal Institute of Technology in Lausanne - EPFL, Lausanne,
Switzerland
Email: dragan.damjanovic@epfl.ch
In the large majority of experimental studies the properties of ferroelectrics are examined throughdielectric (polarization-electric field) or piezoelectric (stress/electric field-charge/strain) relations. It is
well known and since a long time, however, that elastic (strain-stress) properties of ferroelectrics may bevery sensitive at low frequencies to structural phase transitions and domain-walls related
processes.i,ii,iii,iv,v,vi Elastic studies offer complementary information to more common dielectric- andpiezoelectric-oriented investigations and are thus crucial for a better understanding of ferroelectrics.
In this presentation we show results of our recent studies on elastic properties of ferroelectric ceramics.
We employed the dynamic mechanical analyzer technique (DMA), in some cases backed by
piezoelectric resonance measurements, to study several distinct phenomena in ferroelectrics. We
demonstrate that typical relaxor ferroelectric, Pb(Mg1/3Nb2/3)O3, exhibits elastic relaxor behavior, which
we have measured over two orders of magnitude in frequency. That is, Pb(Mg1/3Nb2/3)O3 exhibits what
is today called the “strain glass-like“ behavior.vii We show evidence of octahedral tilts in two
compositions of tetragonal phase of Pb(Zr1-xTix)O3 (x=0.55 and 58), thus confirming results of earlier
infrared spectroscopy studyviii and ab-initio calculationsix. Finally, we give evidence of what appears to
be a strong magneto-elastic coupling in BiFeO3.x

ISAF3-A1-5 ____________________________________________________________________________________________________________________

Ultrasonic determination of anisotropic elasticity of DyScO3
substrates
Hanus Seiner1, Petr Sedlak1, Michaela Janovska1, Michal Landa1,
Pavel Marton2, Petr Ondrejkovic2 and Jiri Hlinka2
1

Laboratory of Ultrasonic Methods, Institute of Thermomechanics, ASCR,
Praha, Czech Republic2
Department of Dielectrics, Institute of Physics ASCR, Praha, Czech Republic
Email: ML@it.cas.cz
Rare-earth scandate single crystals have become very popular as substrate materials for the epitaxial growthof functional thin films, especially in case of ferroelectric and multiferroic perovskite oxides, such as
BiFeO3; EuTiO3; BaTiO3; SrTiO3 or BiMnO3. Hence the elastic constants of the scandates are of highimportance for understanding the behavior of the perovskite films and their further development.
The full elastic tensor of orthorhombic dysprosium scandate (DyScO3) at room temperature was determinedby resonant ultrasound spectroscopy (RUS) complemented by pulse-echo measurement. Measurements(Fig.1) were performed on three 500 um thick substrates with orientations (110), (100) and (001). For thispurpose, a modification of the RUS method was developed, enabling simultaneous processing of the resonant
spectra of several platelet-shaped samples with different crystallographic orientations.
The obtained results are compared with ab initio calculations and with elastic constants of other rare-earth
scandates, and are used for discussion of the in-plane elasticity of the (110)-oriented substrate (Fig2).

Fig.1. Schema of the modal RUS

Fig.2. Anisotropy of the Young’s modulus (E) and the bending rigidity (D) ofthe (110)-oriented DyScO3 substrate.

Piezoelectrics
CLUB B
Monday, July 22 2013, 10:30 am - 12:00 pm
Chair:

Shujun Zhang
Pennsylvania State University

ISAF2-A2-1 ____________________________________________________________________________________________________________________

Complete Description of Piezoelectric Response
in Fundamental Equations
Takaaki Tsurumi, Manabu Hagiwara, Takuya Hoshina and Hiroaki Takeda
Graduate School of Science and Engineering,Tokyo Institute of Technology, Meguro, Tokyo, Japan.
Email: ttsurumi@ceram.titech.ac.jp
Promising applications of piezoelectric ceramics have been changing from devices operated under low
electric fields in electronic circuits to those driven by high electric fields such as actuators for ink-jet
heads, fuel injectors of diesel engines, etc. Under such large-signal operation, response of piezoelectric
ceramics deviates from the conventional linear piezoelectric theory, leading to the appearance of
nonlinear phenomena which causes the unstable operation and heat generation of the devices. Many
researchers have aimed to incorporate the nonlinear and dissipation effects into the piezoelectric theory,
but complete theory of the piezoelectric response have not been established yet. In this study, we willpropose fundamental equations describing the piezoelectric response under the large-signal operation.
The fundamental equations are based on an assumption to simplify the situation: that is piezoelectric e
coefficient is ‘real and constant’. The piezoelectric e coefficient is defined by D = eS, where D and S areelectric displacement and strain, respectively, and D can be regarded as polarization P in piezoelectric
ceramics with high permittivity. Thus, the ‘real and constant’ e coefficient means that S and P have alinear relationship without a phase lag. This assumption stands to reason, since both S and P are
originated from crystal lattice deformation (intrinsic effect) and non-180○ domain wall motion (extrinsic
effect). From a Taylor series expansion of elastic Gibbs energy considering the assumption, we havederived the following nonlinear piezoelectric equations in e-form:T  c E 1* S  c E 2 * S 2  c E 3* S 3  eE  E 2
,

*
*
*
D  eS  2ES   S 1 E   S 2  E 2   S 3 E 3
1.6
Observation

Displacement [μm]where T is stress; E is electric field; cE(i)* is ith-orderelastic stiffness; εS(i)* is ith-order permittivity; γ iselectrostrictive coefficient. Using the above equations, weanalyzed so-called “jump phenomenon” in piezoelectricresonator, which is a discontinuous change of current
and/or displacement in piezoelectric resonator at its
resonance frequency. As shown in Fig. 1, the resonancecurve calculated from the fundamental equations gave avery good agreement with experimental results of PZTbased ceramics driven by high electric field. Moreover,
we also found that the proposed fundamental equation
could describe waveforms of piezoelectric response
distorted by the nonlinear effect.

Calculation(Linear theory)

1.2

Calculation(This study)

0.8
Jumping up

0.4

0
125

130

135

140

Frequency [kHz]Fig. 1: Resonance curve of PZT-based
ceramics (31-mode resonator) driven byhigh electric field.

ISAF2-A2-2 ____________________________________________________________________________________________________________________

Enhanced Large Signal Performance of PZT Thick Film Actuators
for Active Micro-Optics
Dörthe Ernst1, Bernhard Bramlage1, Sylvia Gebhardt1, Oliver Pabst2, Andreas Schönecker1
1
2

Fraunhofer Institute for Ceramic Technologies and Systems (IKTS), Dresden, Germany
Fraunhofer Institute for Applied Optics and Precision Engineering (IOF), Jena, Germany
Email: doerthe.ernst@ikts.fraunhofer.de

In adaptive optics actuators which allow for high precision positioning with short response time areneeded. More often complex actuator structures which can be individually driven are beneficial.
Piezoceramic thick films offer integrated solutions. By the use of screen printing technology, net-shaped
actuator structures can be directly prepared on wafer-level with high accuracy and reproducibility.
At Fraunhofer IKTS piezoceramic thick films based on lead zirconate titanate (PZT) are available. Theyshow excellent small and large signal properties. The paper will report on the performance of bending
actuators based on two different PZT compositions. The results lead into the development of complex
bending structures (Fig. 1c) which will be used to move micro-lens arrays within a flat-building camera.
Top andbottomelectrode+E-field

PZT thick film_

Substrate

a)

b)

c)

Fig. 2:a) Schematic cross section of a PZT thick film layer setup, b) screen printed comb structure, c) actuator frame for
moveable optical elements

The typical layer setup (Fig. 1a) considered consists of a substrate and two flat electrodes (~10 µm) withan intermediate PZT layer (~100 µm). In order to increase the performance of such bending actuators weanalyzed large signal properties, such as free displacement and blocking force, depending on thesubstrate material, the cantilever length and the amount of sintering aid. Comb structures with varied
cantilever length between 11 and 23 mm as shown in Fig. 1b were built on alumina and Low
Temperature Cofired Ceramic (LTCC) substrates. We present the results for two thick film
compositions, our standard PZ 5100 and a new composition PZ 5300.
A PZ 5100 cantilever of 4 mm width and 15 mm length with an amount of 10% sintering aid generates
blocking forces of 112 mN and 107 mN and free displacements of 42 µm and 106 µm for alumina and
LTCC substrates respectively. The new thick film composition PZ 5300, with higher piezoceramic
constants reaches an excellent performance with a sintering aid content of 6.5%. Alumina based
cantilevers of the same dimensions exhibit free displacements of about 70 µm and blocking forces ofabout 180 mN. LTCC based cantilevers show values of about 190 µm and 170 mN.
Actuator frames with a size of 45 x 44 mm² (Fig. 1c) generate a stroke of about 220 µm at 2 kV/mm.
These frames enable an accurate positioning of centrally mounted micro-lens arrays which will beapplied to adapt the focal length of flat-building optical elements.

ISAF2-A2-3 ____________________________________________________________________________________________________________________

Microstereolithography of Piezoelectric Components
David I. Woodward1, Simon J. Leigh2, Connor Watts1, Rui Wang1, Chris Purssell2, Pam A. Thomas1,
Duncan R. Billson2
1

Department of Physics, University of Warwick, Coventry, UK

2

School of Engineering, University of Warwick, Coventry, UK
Email: d.i.woodward@warwick.ac.uk

Microstereolithography (MSL) is an additive manufacturing process whereby a three-dimensional object
is created in an additive, layer-by-layer process. The technology can be used to rapidly create complex
structures with fine resolution of around 20 μm. The process involves creating a digital design of the
final object, slicing this design into a set of cross-sections and then sequentially rendering each crosssection using a thin layer of photosensitive resin. In this way, extremely complex objects such as
interlaced lattices can be built with relative ease.
Our work is concerned with the adaptation of this technique to produce functional composites andceramics. Ferroelectric Pb(Mg⅓Nb⅔)O3–PbTiO3 (PMNT) powder is added to the uncured resin and,once cured, confers the final object with piezoelectric properties. If this composite is heated to thesintering temperature of the PMNT, the organic components are burnt off and the remaining powder
densifies, resulting in a miniaturized ceramic version of the original object.
In this talk, recent results will be presented showing the electrical properties of ‘piezocomposites’
produced by the MSL technique. The effects of sintering will be shown and the effects of modifying theinitial chemistry on the density, structure and piezoelectric and ferroelectric characters of these sinteredcomponents will be discussed and compared with ceramics of the same composition produced byconventional processes. The application of this technique to the production of devices will be illustrated
with some prototype examples.

ISAF2-A2-4 ____________________________________________________________________________________________________________________

Fabrication and Electromagnetic Properties of 3D Photonic
Crystals for Microwave Applications
Wei Dai, Hong Wang
Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education，Xi’an Jiaotong
University, Xi’an 710049, China
Email: hwang@mail.xjtu.edu.cn
Photonic crystals (PCs) as a new periodical structure material have inspired great interests of scientists
and industry for their unique, flexible and desirable photonic band gap properties. On the study of thephotonic crystals, it needs to carry out the structure design, in which the main factors influenced thephotonic band gap should be investigated. It needs to master the photonic crystals fabrication process
and investigate the influences of the various defects introduced into the photonic crystals on thetransmission properties of the electromagnetic wave. In this work, the 3D photonic crystals withdiamond structure for microwave applications
were designed, fabricated and investigated.
Through the theory simulation, the main factors
influenced the photonic bandgaps have beenobtained. The rapid prototyping and gel casting
together with the sintering technique were chosen
as the main fabrication method. Several kinds ofmicrowave ceramics based PCs had been
fabricated and investigated. 13 Then the influenceof periodical lattice constant changing PCs on theelectromagnetic wave propagating properties wasinvestigated. By introducing the defects into thePCs, the influence of point defects, line defects
and planar defects on the electromagnetic wave Fig. 3: The simulation and measurement results ofpropagating properties was studied. 141516 The the perfect diamond 3D EBGs of Alumina with thecoupling of different defect modes has been also lattice constant of 12mm in the dimension of 60
studied and discussed.
mm 60 mm 60 mm. The bandgap is 10.5-12GHz.

13

Yawen Hu, et.al. “Fabrication of three-dimensional electromagnetic band-gap structure with alumina based onstereolithography and gelcasting”, J. Manuf. Sys, vol. 31, p. 22-25, 201214

Wei Dai, et.al. “Effect of point defects on band-gap properties in diamond structure photonic crystals”, J. Appl. Phys., vol.
111, p. 023515, 2012.
15

Wei Dai, et.al. “Bandgap properties of diamond structure photonic crystals with line defects”, J. Appl. Phys., vol. 111, p.
083514, 2012.
16

Wei Dai, et.al. “Planar defects and heterostructure in diamond structure photonic crystals”, J. Appl. Phys., vol. 112, p.
113504, 2012.

PFM-A3-1 ______________________________________________________________________________________________________________________

Nanoscale Domain Wall Phenomena in Epitaxial Bismuth Ferrite Thin Films
Nagarajan VALANOOR1#+
School of Materials Science and Engineering, University of New South Wales, Australia#
Corresponding author: nagarajan@unsw.edu.au +Presenter
In recent years, the control of domains in bismuth ferrite has emerged as a cornerstone of breakthrough science inmultiferroic materials. Domain engineering opens up a vast array of physical phenomena, such as band structure
manipulation, phase transitions and order parameter couplings that are localised at a nanostructured interface, which can thenbe harnessed for electronic applications.
This poses a tantalizing new possibility - can the modulation of the physical properties (such as conductance ormagnetoresistance) of the domain wall be controlled by the geometry of the wall itself? In this presentation, we report theability to create domain patterns and modulate conduction in domain walls by patterning the domain walls with specificcharge and hence conduction in a multiferroic BiFeO3 thin-film. Domain phase control is achieved by specific SPM based tip
writing. The stability of the phases is rationalized by a phase field model. Secondly by controlling domain wall curvature andthe associated divergence in polarization across the wall, a modulation of consuction is achieved along the domain wall. Bothambient and Ultra-high Vacuum (UHV) Scanning probe microscopy (SPM) approaches are employed to show that that the
conductivity of the fabricated curved domain walls can be modulated by up to 500% in the spatial dimension. LandauGinzburg-Devonshire computations reveal that the conduction is a result of carriers or vacancies migrating to neutralize thecharge at the formed interface. Polarization dynamics, studied through phase-field models, highlight that anisotropic
conduction may arise from even initially uncharged ring-domain structures. These results offer the first proof of concept formodulating charge at interfaces in a multiferroic by SPM and further demonstrate that material and electrical parameters canbe extensively controlled at the nanoscale level simply by altering domain geometries. (Vasudevan et al, Nano Letters 2011,2012)
The presentation is a collaborative effort between the presenting author’s group and groups at Oak Ridge NationalLabs, University of Washington, Ukraine National Academy of Sciences and the National Chiao Tung University. The
research at UNSW is supported by the Australian Research Council
1

PFM-A3-2 ______________________________________________________________________________________________________________________

Thermal quench effects on ferroelectric domain walls
P. Paruch1, A. B. Kolton2, X. Hong3,4, C. H. Ahn3, T. Giamarchi1
1

MaNEP-DPMC, University of Geneva, Geneva, Switzerland
CONICET, Centro Atomico Bariloche, San Carlos de Bariloche, Argentina
3
DAP, Yale University, New Haven, CT, USA3
present address: DPA, University of Nebraksa-Lincoln, Lincoln, NB, USA

2

Email: patrycja.paruch@unige.ch
Ferroelectric domain walls present a powerful model system for studying the characteristic roughening
and complex dynamics of elastic interfaces in disordered media [1,2]. Although the equilibriumproerties of such systems are relatively well understood, less is known about their out-of-equilibrium
behavior, and a major challenge is understanding the nonsteady slow dynamics associated with aging[3]. Experimentally, an interesting realization of such phenomena is provided by quenches, in which aparameter, such as the temperature of the system, is abruptly varied.
Using piezoresponse force microscopy on epitaxial ferroelectric thin films, we have measured theevolution of domain wall roughening as a result of such heat-quench cycles up to 735 ◦C, with theeffective roughness exponent ζ changing from 0.25 to 0.5. We discuss two possible mechanisms for theobserved ζ increase: a quench from a thermal one-dimensional configuration and from a locallyequilibrated pinned configuration with a crossover from a two- to one-dimensional regime. We find thatthe postquench spatial structure of the metastable states, qualitatively consistent with the existence of a
growing dynamical length scale whose ultraslow evolution is primarily controlled by the defectconfiguration and heating process parameters, makes the second scenario more plausible. This
interpretation suggests that pinning is relevant in a wide range of temperatures and, in particular, that
purely thermal domain wall configurations might not be observable in this glassy system.We also
demonstrate the crucial effects of oxygen vacancies in stabilizing domain structures [4].
[1] T. Tybell et al, PRL 89, 097601 (2002)[2] P. Paruch et al, PRL 94, 197601 (2005)[3] L. F. Cugliandolo et al, PRL 96, 217203 (2006)[4] P. Paruch et al, PRB (2012)

PFM-A3-3 ______________________________________________________________________________________________________________________

Disorder and environmental effects on ferroelectric domain wall
dynamics
Jill Guyonnet1, S. Bustingorry2, C. Blaser1, E. E. Ferrero2, I. Gaponenko1, J. Karthik3, L. W. Martin3,
and P. Paruch1
1

DPMC, University of Geneva, Switzerland
CONICET, Centro Atómico Bariloche, San Carlos de Bariloche, Río Negro/Argentina
3
Department of Materials Science and Engineering and Materials Research Laboratory, University of
Illinois, Urbana-Champaign, USA
2

Email: jill.guyonnet@unige.ch
Domain wall motion in ferroelectric materials is largely determined by the disorder pinning potential,
which depends on the nature and density of defects in the sample. Readily controlled with electric fields,
and accessible over a large range of length scales and speeds, the domain walls provide an excellent
model system for the complex fundamental physics of elastic disordered interfaces. Understanding the
microscopic role of defects in domain propagation is also technologically critical in increasingly moreminiaturized devices, scaled down to sizes comparable to the extent of individual defects. In thiscontext, scanning probe microscopy (SPM) has emerged as a primary technique for domain engineering,
providing a single well-defined nucleation site and nanoscale resolution of the switching dynamics. In
such studies, the highly inhomogeneous electric field produced by the SPM tip can however besignificantly influenced by the presence of adsorbates on the sample surface, resulting in humiditydependent domain dynamics [1,2].
Here, we present a systematic study of the interplay between disorder pinning and the screening effectsof surface water on the roughness and switching dynamics of SPM-engineered ferroelectric domains in
Pb(Zr0.2Ti0.8)O3 thin films with different defect densities, in ultrahigh vacuum (UHV) and ambientconditions. In samples presenting a low, uniform defect density, the switched domains are circular, withsignificantly higher growth rates in ambient conditions. In contrast, higher-disorder samples show slow
growth rates in both ambient and UHV, with irregular domain shapes in the latter case. Theseexperimental observations are in excellent agreement with Ginzburg-Landau numerical simulations of
the localized nucleation and growth of domains under varying disorder and dipolar interaction
magnitudes.
These results show that, while domain growth rates and roughness are governed primarily by disorder,
electrostatic screening by surface water plays an important role, allowing more rapid domain wallmotion in low-disorder samples, and screening the effects of dipolar and disorder forces in high-disordersamples, which otherwise lead to significant domain wall roughness.
[1] D. Dahan, M. Molotskii, G. Rosenman, and Y. Rosenwaks, Appl. Phys. Lett. 89, 152902 (2006).
[2] V. Ya. Shur, A. V. Ievlev, E. V. Nikolaeva, E. I. Shishkin, and M. M. Neradovskiy, J. Appl. Phys. 110, 052017 (2011).

PFM-A3-4 ______________________________________________________________________________________________________________________

Direct observation of domain wall pinning and creep inferroelectric thin film capacitors
Huizhong Zeng, Yao Lei, Wenbo Luo, Wen Huang, Y. Lin
State Key Laboratory of Electronic Thin films and Integrated Devices, University of Electronic Sci. &Tech. of China, Chengdu, P. R. China
Email: zenghz@uestc.edu.cn
The creep-like motion of ferroelectric domain wall (DW) is crucial to understand the role of defectpinning. A nanoscale scanning probe study of DW pinning and creep motion was preformed inferroelectric thin film capacitors. The ferroelectric capacitors are prepared by pulsed laser deposition of(Pb0.8Zr0.2)TiO3 (PZT) and SrRuO3 (SRO) electrodes onto SrTiO3 single crystal substrates. The ultrathin (<10 nm) SRO top electrode enable piezoresponse force microscope (PFM) to visualize
ferroelectric domains in the capacitors, and provide a homogeneous electric field for studying static anddynamic DW properties. From the static domain wall profiles, the averaged roughness exponent is
extracted to be ~0.39, indicating a 2D DW in the presence of random bond disorder and long range
dipole interaction. By applying the electric pulses (E ≥ EC) to the capacitors, creep-like DW motion was
directly observed. By measuring the averaged speed of DW, the critical exponent is determined to be
μ=1, confirming the random bond disorder. However, a DW roughening process was observed whendecreasing the pulsed electric field. When further decreasing the pulsed electric field, both creep-likemotion and nucleation of bubbles in front of DW were found, indicating the significant role of defectpining. The transition from creep motion to the bubble formation was discussed. Our results suggest thedisordered elastic model oversimplified the DW motion under lower field.

Fig. 4: Motion of domain walls of ferroelectric thinfilms capacitors under pulsed electric field lower
than EC (left) and larger than EC (right). The DW
position before and after electric pulse is colored bydark and orange, respectively. The vertical scan
range of PFM is 6 μm.

PFM-A3-5 ______________________________________________________________________________________________________________________

PFM at variable temperatures: behavior of domains in BaTiO 3
across its orthorhombic to tetragonal phase transition
T. Limböck, A. Hoffmann, E. Soergel
Institute of Physics, University of Bonn, Wegelerstrasse 8, 53115 Bonn, Germany
Email: soergel@uni-bonn.de
We upgraded a commercial, room-temperature AFM with a home-built temperature-controlled sample
holder, allowing for image recording at temperature ranges between –80°C and +120°C. We can not
only record images at different fixed temperatures but also perform "temperature scans", thereby
changing the temperature during the scanning process itself, with the temperature being connected
directly to the scanning process. Figure 1 shows a 20 x 20 µm2 image on BaTiO3 while in changing thetemperature across the orthorhombic to tetragonal phase transition.
Here we report on first results which show that
our setup is working reliably across the wholetemperature range. We therefore imaged a PPLN
sample and showed that the thermal drift is
acceptable (few µm) and the PFM signals(vertical and lateral) are, as expected, independent
on the temperature within the accessible range.
As an interesting candidate for PFM
investigations within this temperature range, wechose BaTiO3, which is known to exhibit a phasetransition at ~ 7°C from orthorhombic totetragonal. Both phases are ferroelectric. Whereas
the classical, high-temperature orthorhombic
phase exhibits 6 directions of the polarization, thetetragonal one has many more. In a first set ofexperiments, we clarified the situation as tounambiguously assign the direction ofpolarization in the PFM images recorded for bothphases of the crystal. We therefore simultaneously
recorded vertical and lateral PFM output
channels.

Fig. 5: PFM temperature scan of a BaTiO3 single
crystal across its phase transition clearly showing
the alteration of the ferroelectric domain pattern.
Image size: 20µm x 20µm. The arrows in the top
right corner indicate the scanning direction.

The next goals are (i) the quantitative information of the piezoelectric coefficients of the two phases, (ii)the investigation of the development of the domains across the phase transition, i.e. which are thepreferred directions of polarization from a certain starting situation and whether there are domain wallsthat maintain their position. Finally we (iii) want to find out why, when heating the sample back to room
temperature (as we did for the data where only cooling is shown in Fig. 1) , the original domain patternbasically is restored.

Pb-based ceramics: Spectroscopy
CLUB A
Monday, July 22 2013, 02:00 pm - 03:30 pm
Chair:Jan Petzelt
Institute of Physics ASCRISAF3-B1-1 ____________________________________________________________________________________________________________________

Soft mode in cubic PbTiO3 by hyper-Raman scattering
Jiri Hlinka1, Bernard Hehlen2, Antoni Kania3, Ivan Gregora1
12Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
Laboratoire des Colloides, Verres et Nanomatériaux (LCVN), UMR CNRS 5587, University ofMontpellier II, Montpellier, France
3
Institute of Physics, University of Silesia, Katowice, Poland
Email: hlinka@fzu.cz

Terahertz-range frequency dispersion of the dielectric
permittivity provides the key information needed tounderstand the potential of practical use of the highpermittivity materials.
Therefore, it seems also important to provide clean
examples of ferroelectric materials where the THz range
permittivity is actually well described by a single polar softmode excitation.
Hyper-Raman scattering experiments allowed collecting
the spectra of the lowest F1u-symmetry mode of PbTiO3
crystal in the paraelectric phase up to  930 K as well as
down to about 1 K above the phase transition. It is realizedthat this mode is fully responsible for the Curie-Weissbehavior of its dielectric permittivity above TC. Near thephase transition, this phonon frequency softens down to 17
cm−1 and its spectrum can be well modelled as a responseof a single damped harmonic oscillator. It is concluded thatPbTiO3 constitutes a clean example of a soft mode-driven
ferroelectric system. Results of this study are partly
available in condmat archive17.
Fig. 6: Unpolarized (V+H) HRS
spectra of in paraelectric phase of
PbTiO3 single crystal for several
temperatures indicated in the figure
with respect to the phase transition(TC  760 K).

17

J. Hlinka, B. Hehlen, A. Kania, and I. Gregora, “Soft mode in cubic PbTiO 3 by hyper-Raman scattering”,
arXiv:1212.3982v1 [cond-mat.mtrl-sci].

ISAF3-B1-2 ____________________________________________________________________________________________________________________

Infrared and terahertz spectroscopy of antiferroelectric PbZrO 3
single crystals
Tetyana Ostapchuk1, Christelle Kadlec1, Petr Kužel1, Jan Kroupa1,
Vladimír Železný1, Jan Petzelt1, Jiří Hlinka1, and Jan Dec2
12

Department of Dielectrics, Institute of Physics, 18221 Prague 8, Czech Republic
Institute of Materials Science, University of Silesia, Bankowa 12, PL-40-007 Katowice, Poland
Email: ostapcuk@fzu.cz

Here, for the first time, we present dielectric dispersion spectra of monodomain PbZrO3 single crystals
obtained along all three orthorhombic axes from far infrared reflectivity and time-domain terahertz
transmission measurements in the 10-500 K temperature range. Within this study we identified thewhole set of the modes, predicted by the factor-group analysis for Pbam structure (11 B1u(z), 17 B2u(y)and 17 B3u(x)). As typical for all Pb-based perovskites, the spectra exhibit three main bands with thelowest one corresponding to the Last-type vibrations, the middle (of the largest mode plasma frequency)
to the Slater-type, and the highest one - to the Axe-type vibrationsxi. The Last-type band of B2u(y)symmetry demonstrates a significant coupling to the Slater-type band at low temperatures, which
gradually vanishes on heating, while in the case of B1u(z) symmetry this coupling is less pronounced andfor the B3u(x) symmetry practically negligible.
The softening of the lowest Last-type band is observed in all three normal-axes directions, but thelargest effect (from ~ 75 cm-1 at T=10 K to ~30 cm-1 at T=500 K) is found along the [001] direction(B1u(z) symmetry), which was suggested to be polar (but not ferroelectric) in the earliest structural
studyxii. In this direction we have also discerned a weak central-mode (CM) type dispersion around 0.3
THz, analogous to the previously observed on the multidomain crystal xiii and ceramicsxiv. Its behavior israther similar to that found in BaTiO3 in the [001] direction of the spontaneous polarizationxv, but its
dielectric strength is several times weaker. In the same sub-THz frequency range in B2u(y)-symmetry
spectra we observed a slightly stronger dispersion, which preserves in the terahertz spectra down to thelowest temperatures, and assigned it to a pseudophason response.

ISAF3-B1-3 ____________________________________________________________________________________________________________________

Compositional tunability of phonons in PZT investigated by
Raman scattering
Elena Buixaderas, Ivan Gregora, Mael Guennou, Jan Petzelt, Jiří Hlinka
Department of Dielectrics, Institute of Physics, ASCR, Prague, Czech Republic
Email: buixader@fzu.cz
Lattice dynamics of ferroelectric perovskite materials, ABO3, is a very fruitful topic of investigation.
Due to the combination of cationic shifts and oxygen-octahedra tilts, different structures can be achievedon cooling from the parent cubic high temperature phase. When one of the cationic sites is occupied by
two atoms many interesting properties can be achieved. This is the case of one of the most investigated
and technologically used materials, the ceramics family Pb(Zr1-xTix)O3 (PZT 100x/100(1-x)), which havesome of the highest piezoelectric coefficients at room temperature for compositions near x = 0.48.
We measured the Raman spectra of a broad range ofcompositions, from the pure rhombohedral (x = 0.25)
to the pure tetragonal side (x = 0.65), crossing the socalled morphotropic phase boundary (MPB), in the
10–800 K temperature range. We also measured
single crystals near the MPB down to He
temperatures.

42/58

48/52

Relative intensity

Dynamics of the low-frequency vibrations —mainly
connected with the Pb atoms— will be discussed andrelated to the recent far-infrared data obtained for thesame samples.18 Doubling of the unit cell at low
temperatures due to the anti-phase tilt of the oxygenoctahedra about the polar axis was confirmed for allcomposition with x < 0.60.

PZT ceramics 10 K

52/48 a52/48 b55/45

-1

The middle frequency band (200–400 cm ), assigned
58/42
traditionally to Ti and Zr vibrations, is the key to thetransformation from tetragonal to rhombohedral
0 100 200 300 400 500 600 700 800
symmetry. The splitting of the E(TO2) mode and the
Wavenumber (cm )19
gradual weakening of one of its components along Fig. 7: Raman spectra of several PZTwith the almost disappearance of the A1(TO2) mode compositions at 10 K.
in the rhombohedral samples, are the most striking
features of this phase transition across the MPB. The parameters of these modes will be discussed inrelation to the symmetry change and to the variation of composition and temperature.
-1

18

E. Buixaderas et al., “Polar lattice vibrations and phase transition dynamics in Pb(Zr1-xTix)O3”, Phys. Rev. B, vol. 84, p.
184302, 2011.
19

E. Buixaderas et al., “Raman spectroscopy of Pb(Zr1-xTix)O3 graded ceramics around the morphotropic phase boundary”,
Phase Transitions, vol. 84, p. 528-541, 2011.

ISAF3-B1-4 ____________________________________________________________________________________________________________________

PbZrO3: nature of the high temperature phase transition
R. Faye1, H. Liu1, D. Kajewski2, K. Roleder2, P. Gemeiner1, B. Dkhil1, and P.-E. Janolin1
1

SPMS laboratory, UMR CNRS-Ecole Centrale Paris, Chatenay-Malabry, France
2
Institute of Physics, University of Silesia,Katowice, Poland
Email: romain.faye@ecp.fr

Despite being the archetypal antiferroelectric perovskite the comprehension of lead zirconate (PZO)
structure and phase transition(s) is still fragmentary. PZO structure remained elusive between the 50's
when its antiferroelectricity was discovered by Shirane 20 and the results of first principles calculations
circa 200021. Since then, the description of the AFE phase by a nonpolar Pbam orthogonal space grouphas been preferred over the polar Pba2 one. Nevertheless a controversy persists over the nature of thehigh temperature phase transition and the existence of an intermediate stable FE phase22. As aconsequence, the structure-property relation has so far not been comprehensively established.
We shall aim at providing insights on these points through temperature dependent X-ray diffraction,neutron scattering, Raman spectroscopy, dielectric, pyroelectric, differential scanning calorimetry, andhysteresis loop measurements performed on ceramics and single crystals. The effect of heat, density,
time and particle sizes on the FE zone will be considered. In addition, we shall report the results oftemperature-dependent X-ray diffraction with in-situ AC electric field.

20

G.Shirane,E. Sawaguchi, “Dielectric properties of lead zirconate”, Phys. Rev. 84,476 (1951)

21

D.J. Singh, “Structure and energetic of antiferroelectric PbZrO3”, Phys. Rev. B 52, 12559 (1995)

22

K. Roleder et al. “The first evidence of two phase transitions in PbZrO 3 crystals derived from simultaneous
Raman and dielectric measurement”, Ferroelectrics 80, 161 (1988)

ISAF3-B1-5 ____________________________________________________________________________________________________________________

Study of ferroelectric-antiferroelectric crossover in PLZT (x/90/10)
ceramics
1

L. Curecheriu1 , L. Stoleriu1, C. Galassi2, F. Fochi2, L. Mitoseriu1
Faculty of Physics, Al. I. Cuza Univ., Bv. Carol I no. 11, Iasi 700506, Romania
2
ISTEC-CNR, Via Granarolo no. 64, I-48018 Faenza, Italy
Email: lavinia.curecheriu@uaic.ro(Pb1-xLax)(Zr0.90Ti0.10)1-x/4O3 [PLZT x/90/10 with compositions: x=0.0, 2.0, 2.5, 3.0, 3.5, 3.8 and4.0] solid solutions have been prepared by solid state reaction and sintering at 12500C/2h. The phase
purity, crystalline symmetry and microstructures have been investigated. Dense ceramics (relative
density above 95-98%) and homogeneous microstructures have been obtained for all the compositions.
The particularities of the switching characteristics at room temperature of these PLZT x/90/10
ceramics were analysed by using the First Order Reversal Curves (FORC) diagrams1. The ferro-antiferro
crossover with increasing x is probed by the transition from one-component Preisach distribution to adouble-maxima symmetric distribution with composition-dependent characteristic bias and coercive
fields (Fig. 1 a, c). For composition in range of x=(3.2-3.8%) was obtained a superposition offerroelectric and antiferroelectric phases characterised by three maxima in the FORC distribution (Fig. 1b).
Impedance spectroscopy in the temperature range of (20, 250)0C demonstrated the shift of theferro-para phase transition with increasing x towards low temperatures. The superposition of ferroantiferroelcetric states is probed by a small dielectric anomaly in the range 70-900C at high frequencies.

x=2%

x=3.2%

x=4%

(a)
(b)
(c)
Fig. 1 FORC distribution showing the ferroelectric-antiferroelectric crossover: (a) ferroelectric (x=2),(b) superposition ferroelectric-antiferroelectric (x=3.2) (c) antiferroelectric (x=4).
Acknowledgements: The financial support of the PN II-PCE-2011-3-0745 is acknowledged.

ISAF3-B1-6 ____________________________________________________________________________________________________________________

Microwave dielectric properties of relaxor ferroelectric
Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals
Li Jin1, Fei Li1, Shujun Zhang2, Dragan Damjanovic3
1

Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International
Center for Dielectric Research, Xi’an Jiaotong University, Xi’an, China
2
Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania, USA
3
Ceramics Laboratory, Swiss Federal Institute of Technology in Lausanne - EPFL, Lausanne,
Switzerland
Email: ljin@mail.xjtu.edu.cn

Relaxor ferroelectric single crystals with the composition near the morphotropic phase boundary (MPB)
region have attracted much attention due to their superior piezoelectric and dielectric properties. Up todate, the routine piezoelectric, dielectric and elastic properties of relaxor ferroelectric single crystals
have been studied. Many representative opinions based on intrinsic crystal lattice and extrinsic domain
wall motion have been proposed to understand high properties. However, their origin is still under
debate.23,24
Ferroelectric materials show strong dielectric dispersion in GHz frequency range, which manifests itself
as the rapid decrease of the permittivity with increasing the frequency and accompanied with a loss
peak.25,26, This phenomenon is mainly attributed to the domain wall motion and piezoelectric grain
resonance.27 By means of this dielectric dispersion, we could distinguish the intrinsic and extrinsic
contribution to the dielectric properties.28 In this presentation, we show results on microwave dielectric
properties of relaxor ferroelectric Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single
crystals. The dielectric response was studied from 100 kHz to 1.8 GHz at temperatures from -100 to 100
oC. By changing the domain wall density through by gradually depoling samples, we evaluated thedomain wall motion contribution to the dielectric properties. A dispersion-free state at GHz range forsingle domain state was observed, where the value (    160 ) measured at 1.8 GHz accounts for the
intrinsic dielectric response of PIN-PMN-PT single crystals.

23

D. Damjanovic, IEEE Trans. Ultrason. Ferroelectr. Freq. Control 56, 1574 (2009).

24

S. Zhang and F. Li, J. Appl. Phys. 111, 031301 (2012).

25

G. Arlt, U. Böttger, and S. Witte, Ann. Phys. 506, 578 (1994).

26

M. P. McNeal, S. J. Jang, and R. E. Newnham, J. Appl. Phys. 83, 3288 (1998).

27

V. Porokhonskyy, L. Jin, and D. Damjanovic, Appl. Phys. Lett. 94, 212906 (2009).

28

L. Jin, V. Porokhonskyy, and D. Damjanovic, Appl. Phys. Lett. 96, 242902 (2010).

Relaxor Materials
CLUB B
Monday, July 22 2013, 02:00 pm - 03:30 pm
Chair:

Takaaki Tsurumi
Tokyo Institute of Technology

ISAF1-B2-1 ____________________________________________________________________________________________________________________

Similarities between the physic of relaxors and other systems
S. Prosandeev1,2, B. Dkhil3
1

Department of Physics, Research Institute of Physics,
Southern Federal University, Rostov on Don 344090, Russia
2
Physics Department and Institute for Nanoscience and Engineering,
University of Arkansas, Fayetteville, AR 72701, USA
3
Ecole Centrale Paris/CNRS UMR8580, Chatenay-Malabry, France
Email: brahim.dkhil@ecp.fr
In this presentation, the main idea is to demonstrate that relaxors share common features with manyother systems; these features being related to various and exotic phenomena like the weak crystallizationin lipids, the Bose condensation in Helium II state or the pseudo-gap in superconductors. The tempting
proximity of these phenomena will be discussed and used to propose a unified microscopic picture of
relaxors. As a matter of fact, two new order parameters will be introduced to characterize the transitions
occurring at Burns temperature and that at T* which marks the crossover between a spherical glass and aquadrupole glass state.

ISAF1-B2-2 ____________________________________________________________________________________________________________________

Temperature Evolution of Dielectric Relaxation in PMN Single
CrystalsViktor Bovtun, Stanislav Kamba, Jan Petzelt, Jiri Hlinka
Department of Dielectrics, Institute of Physics ASCR, Prague, Czech Republic
Email: hlinka@fzu.cz
Dielectric relaxation in PbMg1/3Nb2/3O3 (PMN) was widely studied since 1960. It is observed in broadfrequency and temperature ranges, slows down and broadens on cooling, partially freezes out below thefreezing temperature Tf ≈ 200 K and is characterized by the extremely broad distribution of relaxation
times below Tf. Here we present a detailed analysis of the relaxation based on the complete dielectric
spectra from 3 mHz to 3 THz,which joined our experimental results29-6. Asymmetrical shape the of loss
spectra ′′(log f) indicates the presence of at least two relaxation contributions which are diffuse andoverlapped. The Cole-Cole fit allows separation of two contributions (subscripts “1” and “2”) andevaluation of their parameters: dielectric strength, mean relaxation time 0, relaxation time distribution(RTD) parameter.
Using the uniform RTD function7, upper (U) and lower (L) limits of RTD were determined for bothCole-Cole contributions. Temperature dependences of 02 and L2 can be fitted to the Arrhenius law,while that of 01 and U1 fit well to the Vogel-Fulcher law above 220 K. The longer mean relaxation time
01 does not diverge at Tf and remains finite even below Tf. We attribute this to the crossover from
Vogel-Fulcher to Arrhenius behavior.
As a result of the analysis, we obtained a time-temperature diagram of dielectric relaxation in PMN.
According to the diagram, the relaxation dynamics covers a time range limited by the longest relaxation
time U1 diverging on cooling according to the Vogel-Fulcher law (or et least approaching the Ts range
at Tf) and shortest relaxation timeL2 following the Arrhenius law with a small activation energy (i.e.
week temperature dependent in the ps range).
The described evolution of relaxation dynamics corresponds well to the general scheme of dielectric
response of relaxor ferroelectrics1,8 based on the concept of polar nanoclusters (or nanoregions) whose
flipping and breathing provide two relaxation contributions. The relation of the relaxation dynamics tothe concepts of ferroelectric nanodomains9 or ion chemistry and environment (based on molecular
dynamics simulations10) is under discussion.

29

V. Bovtun, S. Veljko, S. Kamba, J. Petzelt, S. Vakhrushev, et al. - J. Europ. Cer. Soc. 26, 2867-2875, 2006.

2

V.P. Bovtun, N.N. Krainik, L.A. Markova, Y.M. Poplavko, et al. – Fiz. Tverd. Tela 26, 378 – 381, 1984.

3

Y.M. Poplavko, V.P. Bovtun, N.N. Krainik, G.A. Smolensky – Fiz. Tverd. Tela 25, 1263-1265, 1985.

4

E.V.Colla, E.Y. Koroleva, N.M. Okuneva, S.B Vakhrushev - J. Phys.: Cond. Matter 4, 3671–3677, 1992.

5

V.P. Bovtoun, M.A. Leshchenko - Ferroelectrics 190, 185-190, 1997.

6

V. Bovtun, S. Kamba, A. Pashkin, M. Savinov, P. Samoukhina, et al. – Ferroelectrics 298, 23-30, 2004.

7

S. Kamba, V. Bovtun, J. Petzelt, I. Rychetsky, et al.- J. Phys.: Cond. Matter 12, 497–519, 2000.

8

V. Bovtun, J. Petzelt, V. Porokhonskyy, S. Kamba, et al. – J. Europ. Ceram. Soc. 21, 1307-1311, 2001.

9

J. Hlinka – J. Adv. Dielectrics 2, 1241006, 2012.

10

I. Grinberg, Y.H. Shin, A.M. Rappe – Phys. Rev. Lett. 103, 197601, 2009.

ISAF1-B2-3 ____________________________________________________________________________________________________________________

Acoustic evidence of distinctive temperatures inrelaxor-multiferroics
E.Smirnova1, A.Sotnikov1,2, S.Ktitorov3, H.Schmidt2, M.Weihnacht2
12

Department of Ferroelectricity, A.F.Ioffe Physical-Technical Institute, St. Petersburg, Russia,
Department of Magnetic and Acoustic Resonances, IFW Dresden, Dresden, Germany,
3
Department of semiconductors and dielectrics theory, A.F.Ioffe Physical-Technical Institute, St.
Petersburg, Russia
E-mail: esmirnoffa@gmail.com

Structurally disordered perovskites - relaxor ferroelectrics with magnetic ordering (relaxormultiferroics) occupy a special place in the multiferroics family. Coexistence of the relaxor ferroelectricand magnetic subsystems determines their physical properties. The origin of the relaxor state is still
controversial in spite of the long time experimental and theoretical studies. The first and very famous
approach assumes that unique properties of relaxor ferroelectrics are due to the presence of polar
nanoregions (PNR). Some experimental evidences of the creation of PNR in the paraelectric matrix ofrelaxors around so-called Burns temperature (TB) were obtained from the measurements of the opticalrefraction index, thermal capacity, and neutron scattering. Scarce results demonstrate acoustic emission
signals and small elastic anomalies in the vicinity of TB. It is well known that acoustic wave velocity
and attenuation are very sensitive to various processes related to phase transitions, relaxations, glass-likebehavior, etc. Recently, we have reported that peaks of acoustic attenuation at TB and T*(temperature ofassumed nanoscale phase transition due to random field) are revealed in classic relaxor PbMg1/3Nb2/3O3(PMN) and relaxor-multiferroic PbFe1/2Nb1/2O3 (PFN) [1]. The present study is devoted to dielectric andacoustic properties of relaxors with magnetic ordering PbFe1/2Ta1/2O3 (PFT) and PbFe2/3W1/3O3 (PFW)in the temperature range from 100 to 700 K. The samples were prepared by a conventional ceramic
technique. Longitudinal ultrasonic wave velocity and attenuation as a function of temperature were
determined by ultrasonic pulse-echo method at frequencies of 5 and 10 MHz (PFT) and 10 MHz (PFW).
Peaks of attenuation in the vicinity of the dielectric constant maximum temperature Tm, suggested Burns
temperature TB and specific temperature T* are found for PFT, as well as for PFW.
The results are discussed on the base of PNR model and on the classical idea by Mandelshtam andLeontovich of the slowly relaxing internal parameter. This method being applied to the soundpropagation and attenuation problem allows us to describe the acoustic anomaly in the vicinity of Burns
temperature. Slowed-down relaxation in the PNRs leads to an incomplete equilibrium of the system,
and, therefore, to the energy dissipation. PNRs are considered as randomly distributed short-range
relaxing centers interacting with the long-wave acoustic waves. Polarization located in PNR plays a roleof such relaxing parameter. PNR are assumed to have a shape of the ellipsoid; the aspect ratio of it
determines a relative effectiveness of the polarization interaction with the longitudinal and transverse
acoustic waves. Comparison of the results of averaging of the dielectric and acoustic parameters over the
PNR’s configurations with experimental data gives a possibility to estimate the most probable aspectratio of the PNR.
1

E.Smirnova, S.Ktitorov , A.Sotnikov, H.Schmidt, M.Weihnacht, “ High Temperature Acoustic Effects
in Relaxors PbMg1/3Nb2/3O3 and PbFe1/2Nb1/2O3”, Proceedings ISAF/ECAPD/PFM 2012,#6297789, 2012

ISAF1-B2-4 ____________________________________________________________________________________________________________________

Relaxation of Polarized State Createdby Local Electric Field in SBN Single Crystals
Shikhova Vera1, Shur Vladimir1, Shvartsman Vladimir2, Lupascu Doru2, Ievlev Anton1,
Neradovskiy Maxim1, Pelegov Dmitry1, Lebedev Vasily3, Ivleva Lyudmila4, Dec Jan5
1

Feroelectric laboratory, Ural Federal University, Ekaterinburg, Russia
Institute for Materials Science, University of Duisburg-Essen, Essen, Germany
3
Faculty of Materials Science, Moscow State University, Moscow, Russia
4
General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
5Institute of Materials Science, University of Silesia, Katowice, Poland
2

Email: vera.shikhova@labfer.usu.ru
The temperature and temporal relaxation of the polarized state created by application of the local electricfield using conductive tip of the scanning probe microscope was investigated in pure and doped by Ce
single crystals of relaxor ferroelectric SrxBa1-xNb2O6 (SBN) with x = 0.61 and 0.75.
The 0.5-mm-thick plates of SBN single crystals were cut normally to the polar axis and carefully
polished. The samples before measurements were treated by two alternative procedures:(1) thermal depolarization (creation of the multi-domain state) by heating up to 200OC and zero-fieldcooling, (2) creation of the single domain state by application of 30–50 bipolar triangular or rectangularfield pulses with amplitude and duration sufficient for complete polarization reversal at room
temperature using liquid electrodes.
The polarized areas were created under the action of local electric field of both directions with amplitude
ranged from 40 to 100 V and duration from 1 ms to 1 s at room temperature and at elevated temperature
up to 100OC (above freezing temperature for all compositions). The difference between piezoelectric
responses in the polarized areas produced by application of the field of opposite sign (“contrast”) has
been obtained. The temporal relaxation of the contrast value has been measured at various temperatures.
It was shown that increasing of the field amplitude and pulse duration leads to higher stability of thepolarized state (increasing of the relaxation time constant). The polarized state created in the crystals inthe single domain state was remarkably more stable than in the crystals in the multi-domain state.
Moreover it has been shown that the diameter of the area created at elevated temperatures decreasing
with increasing the temperature. The average value of the induced contrast decreased gradually during
heating and with the increase of the creation temperature for all investigated crystals.
The obtained effects have been attributed to field induced partial polarization of the multidomain stateand important role of the backswitching under the action of depolarization field leading to relaxation of
the piezoresponse value. The acceleration of backswitching at the temperatures above freezing point has
been attributed to additional input of the phase boundaries.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has beenused. The research was made possible in part by RFBR (Grants 13-02-01391-а, 11-02-91066-CNRS-а,
12-02-31377); by Ministry of Education and Science (Contracts 14.513.12.0006, 16.740.11.0585), by
OPTEC LLC and UrFU development program.

ISAF1-B2-5 ____________________________________________________________________________________________________________________

Structural Origins of Strain and Fatigue in 94%(Bi1/2Na1/2)TiO36%BaTiO3
Hugh Simons1, John E. Daniels2, Julia Glaum2, Jacob L. Jones3, Andrew J. Studer4, Mark Hoffman2

2

1
Department of Physics, Technical University of Denmark, Lyngby 2800, Denmark
School of Materials Science & Engineering, University of New South Wales, Sydney, NSW 2052, Australia
3
Department of Materials Science & Engineering, University of Florida, Gainesville, FL 32611, USA
4
Bragg Institute, Australian Nuclear Science & Technology Organisation, Kirrawee, NSW 2234, Australia

Email: husimo@fysik.dtu.dk
94%(Bi1/2Na1/2)TiO3-6%BaTiO3 (BNT-6BT) remains one of the most intensively studied lead-freeferroelectric composition for high-strain applications30. At elevated temperatures (T>75°C), large
recoverable strains (Smax~0.4%) can be attained with low hysteretic loss, accompanied by a reversible
electric-field-induced relaxor-to-ferroelectric transition. However, its ultimate applicability is hinderedby uncertainties regarding the role of this structural transformation on the strain mechanism and fatigue
life. Here, we describe the temperature-dependence of this transition from 25˚C to 100˚C, and its
influence on the macroscopic strain and fatigue.
Orientation-dependent structural measurements
were carried out using neutron diffraction under insitu electric fields and elevated temperatures,
requiring the development of specialized sample
environments and analysis processes. By
calculating domain switching fractions as a functionof temperature and electric field amplitude, thelarge recoverable strain observed at elevatedtemperature was shown to be associated with thereversible nature of the field induced phasetransformation31.
In
addition,
structuraltransformation occurring during bipolar electricalfatigue was investigated using a similar technique,highlighting a fatigue mechanism by which
domains are progressively pinned and fragmented32.
When heated close to the ferroelectric-relaxortransition temperature, the fatigue degradation
reduced significantly, an improvement attributed to Fig. 8: Normalized strain from the contribution of nonthe unstable domain structure near the relaxor 180° domain wall motion in the tetragonal andrhombohedral phases. The strain is calculated from thetransition.
relative positions and intensities of the {002} pc and{111}pc reflections respectively.
30

W. Jo, R. Dittmer, M. Acosta, J. Zang, C. Groh, E. Sapper, K. Wang, and J. Rödel, “Giant electric-field-induced strains in lead-freeceramics for actuator applications – status and perspective”, J. Electroceram. 29, 71 (2012)31

H. Simons, J.E. Daniels, J. Glaum, A.J. Studer, J.L. Jones and M. Hoffman, “Origin of large recoverable strain in 94%(Bi1/2Na1/2)TiO36%BaTiO3 near the ferroelectric-relaxor transition”, Appl. Phys. Lett. 102, 062902 (2013)32

H. Simons, J. Glaum, J.E. Daniels, A.J. Studer, A. Liess, J. Rodel, and M. Hoffman, “Domain fragmentation during cyclic fatigue in
94%(Bi1/2Na1/2)TiO3-6%BaTiO3” J. Appl. Phys. 112, 044101 (2012)

ISAF1-B2-6 ____________________________________________________________________________________________________________________

Julia Glaum1, Hugh Simons1,3,4, Mark Hoffman1
Matias Acosta2
1 School of Materials Science and Engineering, University of New South Wales, NSW 2052, Australia
2 Institute of Materials Science, Ceramics Group, Technische Universität Darmstadt, Germany
3 School of Physics, Technical University of Denmark, Lyngby, Denmark
4 European Synchrotron Radiation Facility, Grenoble 38000, France
j.glaum@unsw.edu.au
Temperature-dependency of the relaxor-ferroelectric transition in BNT-BZT ceramics
Piezoelectric ceramics are used in a wide range of actuating applications, utilizing their characteristic totransform electrical power into mechanical strain. In pure ferroelectric compositions the strain
mechanism is based on the reorientation of ferroelectric domains and the intrinsic elongation of the unit
cells along the direction of the applied field. However, in relaxor-type ceramics a third mechanism cancontribute to the strain. It is based on an electric-field-induced transformation between themacroscopically non-polar relaxor state and the polar ferroelectric state and the associated high degreeof domain alignment. In these materials the maximum unipolar strain is achieved at temperatures close
to the transition temperature TF-R where the ferroelectric state becomes unstable in the absence of an
external electric field.
One of the most promising lead-free piezoelectric systems is (Bi1/2Na1/2)TiO3-6BaTiO3 (BNT-6BT) withelectromechanical properties similar to the widely used Pb(Zr,Ti)O3 system. It exhibits relaxor
characteristics and a ferroelectric state can be induced by electric field application. The transition
temperature for BNT-6BT ceramics appears to be around 80°C. Doping with small amounts of Zr was
found to increase the maximum strain, which makes this modification of BNT-BT interesting for highstrain applications.
This study investigates the influence of Zr-doping on the electric field induced relaxor-ferroelectrictransition of the system BNT-6BT. Zr addition leads to a de-stabilization of the induced ferroelectricorder, resulting in a lower transition temperature TF-R and a corresponding increase in unipolar strain.
However, the electric field E* needed to induce this transition appears to be only slightly temperaturedependent. Temperature dependent polarization and permittivity measurements will be utilized to
explore the temperature-electric field diagram.

PFM2
CLUB C
Monday, July 22 2013, 02:00 pm - 03:30 pm
Chair:To Be Announced

PFM-B3-1 ______________________________________________________________________________________________________________________

Electrical Modulation of the Local Conduction at BiFeO3-CoFe2O4
Tubular Oxide Interface
Ying-Hao Chu
Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
30010, R.O.C.
Email: yhc@nctu.edu.tw
Complex oxide interfaces emerge as one of the most exciting subjects among condensed matters due totheir unique physical properties and new possibilities for next-generation electronic devices. Three typesof complex oxide interfaces have been established. Among them, the most explored interface is theartificially constructed heterointerfaces. Various interactions at the interface have resulted in a numberof exciting discoveries, such as highly mobile quasitwo dimensional electron gas (2DEG) forms between
two band insulators (LaAlO3 and SrTiO3). Moreover,in ferroic oxides, domain walls dictate natural homointerfaces as a consequence of the minimization ofelectrostatic and elastic energies. Several key studies
have pointed out interesting observations, such as
local conduction, on domain walls in multiferroics.
Recently, new tubular oxide interface has beendeveloped in the self-assembled heterostructures andthe local conduction at the tubular interfaces of
BiFeO3 (BFO)-CoFe2O4 (CFO) heterostructure was Figure 1. (a) The diagram of BFO-CFO
found. Such results create a huge playground to nanostructures. CFO nanopillars (yellow) are
explore and design intriguing properties of complex embedded in the BFO matrix (blue), and hence theoxide interfaces. However, in the push for practical tubular interfaces (Red) form between these two
applications, it is desirable to have the control of the materials. (b) The topography and (c) the current
interface functionalities through external stimulus. An image of BCFO are gained simultaneously underelectrical modulation of the local conduction at the the CAFM mode where the current is read byhomo- (BFO domain walls) and hetero-interfaces applied +0.05V sample bias. (d)~(f) the conduction(LaAlO3/SrTiO3) was demonstrated recently. In this currents at tubular interfaces can be turn on and off
study, we went back to the BFO-CFO tubular by applying larger DC bias (8 V) of different
interfaces and showed the interface conduction can be polarity. (g)~(l) currents at four sides of the tubularinterface can be switched individually.
modulated non-volatile and reversibly via an external
electric field by using conducting AFM (Figure 1). A
memristive-like electronic conduction was observed, that is strongly correlated to the motion of oxygen
vacancies (donor impurities) at the interface and in turn modifies the junction characteristics between themeasurement tip and interface. Our results complete the control of the conduction at complex oxideinterfaces and suggest the possibility for new devices based on complex oxide interfaces.

PFM-B3-2 ______________________________________________________________________________________________________________________

Anomalous Photovoltaic effect in BiFeO3
Akash Bhatnagar, Marin Alexe
Max Planck Institute of Microstructure Physics
Weinberg 1, 06120 Halle (Saale),Germany
e-mail: malexe@mpi-halle.mpg.de

In the recent past, the entire field of photo-ferroelectrics has been revitalized by the reports ofphotovoltaic (PV) effect in BFO. Unlike traditional semiconductors the open circuit voltages in BFO are
not limited by band gap. Initial investigations assumed that the PV effect in BFO is primarily due to thepresence of a potential step at the domain wall which enables a more efficient separation of charge
carriers [xvi]. However, in a recent work [xvii] it was observed that the generation and recombination ofphoto-generated non-equilibrium carriers in a BFO single crystal are primarily affected by the presenceof shallow energy levels and the domain walls might not playing a major in the corresponding PV effect,
as initially proposed. Thus, till now there is not yet a clear model of the PV effect in BFO. In this work,in order to get a further insight into the actual mechanism for the generation of PV effect in epitaxial
BFO thin films, time and temperature resolved measurements have been performed. Time resolved
measurements, namely photo induced transient spectroscopy (PITS) bring valuable data regarding
generation and recombination of the photo-excited carriers. Providing that the ferroelectric domain
configuration in BFO does not change at low temperature, variable temperature measurements of PV
effect can provide information on details regarding the electronic structure of BFO, respectively shallow
or deep levels in the band gap, that may affect the conduction mechanism as reported in [2].

PFM-B3-3 ______________________________________________________________________________________________________________________

Optimization of carbon nanotube tips for improved scanningprobe microscopy studies of ferroic thin films
Yuliya Lisunova1*, J Heidler2, I. Levkivskyi3, I. Gaponenko1, A. Weber2, L.J. Heyderman2, C.Cailler1,
M. Klaui4 and P. Paruch1
1
DPMC-MaNEP, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4,Switzerland
2
Paul Scherrer Institut , 5232 Villigen PSI, Switzerland
3
DPT, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
4
University of Mainz, Institute of Physics, Staudinger Weg 7, 55128 Mainz, Germany
Email: yuliya.lisunova@unige.ch
Scanning probe microscopy is an essential research tool for both fundamental and technology-driven
studies, mapping diverse functional properties in a wide range of materials with a nanoscale resolution,
defined by the specific tip geometry and properties. Its imaging capacity can be significantly enhanced
by carbon-nanotube-based (CNT) tips [1], whose small size and outstanding mechanical and electricalproperties improve resolution in topographical, electrostatic and surface potential microscopy modes.
Further modification of the CNT tips [2-3] extends their application to magnetic force microscopy, whenferromagnetically coated, and to contact-based techniques, when rigidified with an insulating silicon
dioxide layer. In the rapidly developing field of domain wall nanoelectronics [4], such ultra-highresolution tips could provide unprecedented access to the novel and highly localized functional
properties of domain walls in ferroelectric and magnetic materials.
Here, we report on extended studies of such CNT tips, benchmarking their properties againstcommercially available tips on ferroic thin films. Introducing molecular beam epitaxy deposition ofcobalt on single-walled CNT, we demonstrate sub-10 nm resolution in hard magnetic samples, and nonperturbative magnetic force microscopy imaging of complex domain and domain wall (DW) structuresin micropatterned permalloy, both at ambient conditions [5]. We also develop theoretical models
allowing us to extract the key imaging parameters and their dependence on the tip properties, and tailor
the tip design to optimize resolution under given measurement conditions [5]. Integrating rigidified tips
in ferroelectric thin film studies, we demonstrate more precise spatial resolution of the conducting
region, allowing us to determine the minimal separation of DW in potential nanoelectronic devices, andthe writing and reading of ferroelectric domain structures. These results are expected to have an impact
on future probe-based technology, data storage and material characterization.
References[1] J.H. Hafner et al. J. Am. Chem. Soc. 121, 9750 (1999)[2] H. Kuramochi et al. Nanotechnology. 16, 24 (2005)[3] N. Tayebi et al. Appl. Phys. Lett. 93, 103112 (2008)[4] G. Catalan et al. Rev. Mod. Phys. 84, 119 (2012)[5] Y. Lisunova et al. Nanotechnology 24 105705 (2013)

PFM-B3-4 ______________________________________________________________________________________________________________________

Characterizing piezoelectric MEMs displacement
J. Evans, S. Chapman
Radiant Technologies, Inc., Albuquerque, NM USA
Email: sframboss@ferrodevices.com
Piezoforce Response Microscopy is a popular tool for studying ferroelectric and piezoelectric materials
at the nanometer level.33,34 Progress in piezoelectric MEMs (pMEMs) fabrication is highlighting theneed to characterize absolute displacement at the nanometer and Ångstrom scales, something AFM
might do but PFM cannot. The lack of calibration standards for atomic force microscopes at thosescales plus high ambient noise levels exceeding the maximum displacement under study make accurate
displacement characterization difficult. Nevertheless, once acceptable accuracy has been achieved it
becomes possible to measure converse d33 for thin piezoelectric films and to determine the motions of
MEMs structures that are far too complex to accurately simulate using finite element analysis tools.
Absolute displacement measurement at the pMEMs level must target electroded devices. A major issue
is that the demand for electrical current by electroded ferroelectric capacitors easily destroys the lightly
metalized conductive cantilever tips used for PFM studies. This issue requires the development of morerobust cantilevers to actuate pMEMs capacitors. Reliable conductive cantilevers make possible longterm studies of actuator reliability, uniformity,
and yield, all of which are prerequisites for
manufacturing.
As fully integrated pMEMs
devices become available, the top electrode metal
will be passivated by glass or other layers.
Conductive cantilevers will no longer be needed
since electrical connections will occur through thesample chuck to the pMEMs package pins. These
extra layers above the actuator capacitor arenecessary for long term product reliability but
they will greatly complicate modeling device
performance in product form. The results of ongoing research by the authors on pMEMs
characterization progress and challenges will be Fig. 9: 1-micron-thick niobium-dope PZT capacitor
presented.
and its displacement butterfly loop.

33

S. V. Kalinin and A. Gruverman, “Scanning Probe Microscopy of Functional Materials, Nanoscale Imaging andSpectroscopy”, Springer, 2011
34

M. Alexe and A. Gruverman, “Nanoscale Characterization of Ferroelectric Materials: Scanning Probe Microscopy
Approach”, Springer, 2004

Lead-free ceramics: StructureCLUB A
Monday, July 22 2013, 04:30 pm - 06:00 pm
Chair:

Jacob Jones
University of Florida

ISAF3-C1-1 ____________________________________________________________________________________________________________________

Tilted or Distorted Octahedra in Perovskite Structures - what is
the limit of what we can learn from powder diffraction?
Pam Thomas1, Mike Glazer1&2, Dean Keeble1, David Woodward1
1 Department of Physics, University of Warwick, Coventry CV4 7AL, UK
2 Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK
Email: p.a.thomas@warwick.ac.uk
Powder diffraction, whether by x-rays or neutrons, is well known as a technique for “finger-printing”
crystal structures of all sorts, with automated search-match procedures and databases such as the ICDD
making this practice relatively routine in many cases. However, when dealing with highly pseudosymmetric structures that are derived either actually or theoretically from a cubic aristotype, powder
diffraction patterns must be scrutinized with considerable rigour and one must rationally discriminate
between very similar refinement fits to derive the correct structural model. In so doing, factors such as
the resolution of the experiment and the broadening contributed by the sample must also be correctly
accounted for.
In perovskite structures it has well been known since the seminal work of Glazer in the 1970’s, that thestructure can distort via tilting (rotating) of the oxygen octahedra about the unit cell axes of the parent
phase. These tilts can be classified according to the Glazer notation and their effects on the powder
pattern calculated. In particular, different systems of oxygen octahedral tilts lead to doublings of the unit
cell, which are detected via super-structure peaks (often called “tilt peaks” in common parlance). It is
usual for materials scientists (physicists, chemists etc) to look for particular super-structure peaks e.g.
orin a powder pattern to conclude that they have antiphase or in-phase octahedral
tilts, respectively.
In recent work on refinements of the crystal structure of the archetypal lead-free piezoelectric sodium
bismuth titanate, Na0.5Bi0.5TiO3 (NBT), in its tetragonal phase (at T>673K), we have discovered apreviously unconsidered characteristic of powder patterns for perovskites. In this talk, we will show how
there is a degeneracy in the powder patterns for (a) a tilted octahedral model of the structure or (b) a
distorted but untilted octahedral model of the structure. The effect of this is that the computed powder
patterns of these two quite different structures are virtually indistinguishable from each other, a very
unusual situation in powder diffraction! The implications of this for the wider interpretation of powder
diffraction data for a range of perovskite structures, including some fluorides with highly distorted(fluorine) octahedra, are discussed.

ISAF3-C1-3 ____________________________________________________________________________________________________________________

Lead-free Piezoelectric Ceramics (Na0.5K0.5)NbO3 doped with
LiTaO3 and BiScO3
Fangyuan ZHU1, Jing-Feng Li1, Michael B. Ward2, Tim P. Comyn2, Andrew J. Bell2 and Steven J.
Milne2
1

School of Materials Science and Engineering, Tsinghua University, Beijing, China
2
Institute for Materials Research, SPEME, University of Leeds, Leeds, UK
Email: jessie-zhufangyuan@hotmail.com

A series of compositions along the compositional join in the ternary NKN-LT-BS system,
extending from 0.98Na0.5K0.5NbO3-0.02BiScO3 toward LiTaO3 have been prepared and characterized. A
composition [NKN0.98-(LiTaO3)0.02]0.98–[BiScO3]0.02 showed enhanced piezoelectric properties, relative
to similar compositions, with d33 values of 215 pC/N. This can be attributed to a phase content of mixed
orthorhombic (or monoclinic) and tetragonal phases at ambient temperatures. Variable temperature Xray diffraction (XRD), and dielectric measurements as a function of temperature, indicated phasetransitions (on heating) from an orthorhombic (or monoclinic) crystal system to tetragonal and thencubic crystal systems at ~25°C and ~370°C respectively.
Different types of dielectric behavior were observed on increasing the LT content. A NKN5%LT-2%BS composition exhibited twin dielectric peaks at high temperatures (~370°C and ~470°C),
along with broad X-ray diffraction peaks and a fine grain size, < 0.5 μm. The twin dielectric peaks
suggest that chemical inhomogeneities may have been present; this was examined using transmission
electron microscopy (TEM) with energy dispersive X-ray analysis (EDX). Elemental segregation wasobserved within individual grains, such that a core-shell grain structure was evident. Subsequently, aseries of other compositions were prepared in the wider Na0.5K0.5NbO3-LiTaO3-BiScO3 ternary system.
Considering the combined data from XRD, dielectric measurements, SEM, TEM andpiezoelectric properties for a wide range of compositions within the NKN-rich region of the NKN-LTBS system, materials may be grouped into three categories, exhibiting the following defining
characteristics.
Type I: single, sharp dielectric Curie peak (~370°C); single phase by XRD; large grain size (510μm); chemically uniform by TEM-EDX.
Type II: broad, single dielectric peak (~350°C); single phase by XRD; large grain size; noobvious chemical segregation.
Type III: twin, broad dielectric peak(s) (~370°C and ~470°C); broad XRD peaks; small grain
size (~0.5μm); chemical segregation (core-shell structure) identified by TEM-EDX.

ISAF3-C1-4 ____________________________________________________________________________________________________________________Breaking of the centric symmetry in ferroelectric and paraelectricphases of unpoled ceramics.
Alberto Biancoli1 and Dragan Damjanovic1
1

Ceramics Laboratory, Swiss Federal Institute of Technology in Lausanne –EPFL, Switzerland.
Email: alberto.biancoli@epfl.ch

In the recent years, flexoelectricity attracted a growing interest as an electro-mechanical couplingmechanism alternative to piezoelectricity and electrostriction. Flexoelectric polarization is proportional
to elastic strain gradient, which scales inversely with the size of sample, and thus was in general
expected to play a major role only on nano-scale. In the past decade however, the experimental findingof large apparent flexoelectric coefficients in bulk ferroelectrics (three to four order of magnitude larger
than theoretically predicted) raised the hope to exploit flexoelectricity for practical applications in bulk
materials as well.
On the other hand, the recent observation of piezoelectric and pyroelectric-like responses in unpoled
ferroelectric and paraelectric phases of ceramics suggests a breaking of the macroscopic centric
symmetry caused by a mechanism other than the already known symmetry breaking induced underelectric field. An insight into the origin of this breaking of the symmetry would have important
implications on the understanding of the flexoelectric effect in bulk materials and may provide an
explanation for the unexpectedly high apparent flexoelectric polarization reported for some bulk
materials.
We report here on investigations of the described spontaneous symmetry breaking in unpoled ceramics.
Materials examined include BaTiO3, SrTiO3, Ba1-xSrxTiO3, (Ba,Ca)(Zr,Ti)O3 and PbZr1-xTixO3 solid
solutions. Barium titanate, Ba1-xSrxTiO3, (Ba,Ca)(Zr,Ti)O3 were examined both below and above theirCurie temperature. A number of systematic studies were performed in a search for a possible driving
force for the symmetry breaking.
The influence of dielectric permittivity, temperature, surface electrodes and grain size on apparent
electro-mechanical and pyroelectric response of unpoled ferroelectric and paraelectric samples werestudied. Grain size of a BaTiO3 sample could be changed by thermal annealing. A fine-grained BaTiO3
sample with a large permittivity exhibits a lower pyroelectric response than the same sample with alarger grain size and a lower permittivity. Response in BaTiO3 and SrTiO3 ceramics was compared tothat in respective single crystals. Both ceramics and single crystals of BaTiO3 exhibit nonzero
piezoelectric and pyroelectric signals above the Curie temperature. Within resolution of ourmeasurements, neither single crystal nor ceramics of SrTiO3 show any symmetry breaking at room
temperature. Pressing and sintering conditions for ceramics were analyzed and it was found that thecooling rate after sintering does not significantly affect the response.

ISAF3-C1-5 ____________________________________________________________________________________________________________________

Laser Beam Scanning Microscopy Observation of Domain
Switching in NaNbO3 Epitaxial Film
Ichiro Fujii, Akihiro Kohori, Seiji Yamazoe, and Takahiro Wada
Department of Materials Chemistry, Ryukoku University, Otsu, Shiga, Japan
Email: ifujii@rins.ryukoku.ac.jp
Domain switching, or polarization reversal, substantially affects the dielectric and piezoelectric
properties of ferroelectric materials. Thus, it is important to understand how the domain structurechanges with the electric field amplitude. Laser beam scanning microscopy (LSM) with a polarizer is amethodology that allows us to see domain patterns and their polarization directions.35, 2 We applied thistechnique to a 001-oriented NaNbO3 (NN) film, and observed a drastic change in the domain structure
after a large electric field of 230 kV/cm was applied. In this study, evolution of the domain patterns offerroelectric 001-oriented NN film was observed using LSM during application of ac electric fields withsmaller amplitudes, and the domain structures were analyzed.
Before deposition of the NN film, we deposited SrRuO3 (SRO) film as a bottom electrode on (001)
SrTiO3(STO) substrate by pulsed laser deposition (PLD). Then, a 001-oriented NN film was prepared ona (001) SRO/(001)STO substrate by PLD. Pt top electrodes were formed on the NN film by sputtering.
An electric field large enough to induce the ferroelectric response was applied by measuring polarization– electric field (P-E) loops with a ferroelectric tester. The domain structures were observed by LSM
during the application of a triangular electric field. Here, a polarizer was placed between the film and theobjective lens, and rotated to see the polarization directions of the domains.
A ferroelectric P-E loop was observed for the NN film when an ac electric field amplitude of 100 kV/cm
was applied. Figure 1 (a) shows a
representative LSM image of the NN film.
Rotation of the polarizer found that thedomain structure consisted of the vertical andhorizontal domains and the slanted domains,asillustrated in Fig. 1 (b). When the electric field
decreased from maximum electric field(+Emax) to minimum electric field (–Emax), twodifferent domain-switching routes wereobserved. One is that the slanted domains
changed to vertical and horizontal domains,which then reverted to slanted domains. Thesechanges indicated that the polarization
direction, for example, changed from out-of- Fig. 1: (a) LSM image of NN film using 45˚
plane[101] to in-plane [110] and to out-of-plane polarized laser beam, and (b) schematics of[10-1].
polarization directions of domains.
The other route will be also discussed.

35
2

S. Yamazoe, H. Sakurai, T. Saito, and T. Wada, Appl. Phys. Lett., 96, 092901 (2010).

S. Yamazoe et al., J. Appl. Phys. 112, 052007 (2012).

Materials for High Power and High Temperature Applications
CLUB B
Monday, July 22 2013, 04:30 pm - 06:00 pm
Chair:

Ian Reaney
University of Sheffield

ISAF1-C2-1 ____________________________________________________________________________________________________________________BaTiO3 – Bi(Zn1/2Ti1/2)O3 – NaNbO3 Dielectric Ceramics for
Advanced Capacitor Applications
Natthaphon Raengthon1, Harlan J. Brown-Shaklee2, Geoff L. Brennecka2 and David P. Cann1
1

Materials Science, School of Mechanical, Industrial, and Manufacturing Engineering,
Oregon State University, Corvallis, OR, USA
2
Electronic, Optical, and Nanostructured Materials Department, Sandia National Laboratories,
Albuquerque, NM, USA
Email: raengthn@onid.orst.edu
Dielectric ceramics for high temperature electronics are desired for advanced technologies since existing
technologies of ceramic capacitors (X7R or NP0) are not compatible with extreme environments, especiallyat temperatures higher than 200 ºC. In recent years, several research groups have developed new BaTiO3 –based materials that exhibit promising dielectric properties for high temperature applications. Previous
studies on BaTiO3 – Bi(Zn1/2Ti1/2)O3 – BiScO3 ceramics demonstrated that a temperature-stable permittivity
can be obtained over a broad temperature range36. However, a large change in permittivity between room
temperature and 100 ºC persisted which might limit the usage of the material over that temperature range.
Therefore, BaTiO3 – Bi(Zn1/2Ti1/2)O3 – NaNbO3 ceramic solid solutions were investigated. The effects of
BaTiO3 and NaNbO3 additions on the dielectric properties of ternary compounds are of interest. A
broadening of the temperature-dependent permittivity maximum and a decrease in overall permittivity wereobserved when the content of BaTiO3 decreased while the Bi(Zn1/2Ti1/2)O3:NaNbO3 ratios were kept
constant. A shift in the temperature of the maximum permittivity (Tmax) down to -103 ºC was achieved whensubstituting Bi(Zn1/2Ti1/2)O3 with NaNbO3 for the compositions with constant BaTiO3 concentration. A
broad permittivity peak was observed in several compositions that was comparable to other BaTiO3 –Bi(Zn1/2Ti1/2)O3 based ceramics as shown in Figure 1. The
dielectric characteristics of the 50BT-25BZT-25NN
composition also satisfies the X9R standard (ΔC/C25 = ±15%over a range of -55 to 200 ºC). A linear dielectric response isalso presented under high electric fields at various
temperatures. In conclusion, the investigation of BT-BZTNN compounds resulted in promising dielectric properties
with broad temperature ranges with a high permittivity, which
is of interest for advanced capacitor applications.
Figure 1. Temperature dependence of relative permittivity of Bi(Zn1/2Ti1/2)O3 – BaTiO3 based
compounds (BZT: Bi(Zn1/2Ti1/2)O3, BT: BaTiO3, BI: BiInO3, BS: BiScO3, NN: NaNbO3).

36

N. Raengthon, T. Sebastian, D. Cumming, I. M. Reaney, and D. P. Cann, “BaTiO3 – Bi(Zn1/2Ti1/2)O3 – BiScO3 Ceramics for HighTemperature Capacitor Applications”, J. Am. Ceram. Soc., 95[11] 3554-3561 (2012).
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of
Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC0494AL85000. This work was supported by the Department of Energy’s Office of Electricity Delivery and Energy Reliability, Energy
Storage Systems program managed by Dr. Imre Gyuk.

ISAF1-C2-2 ____________________________________________________________________________________________________________________

Large Field Property Assessment of Mn:PIN-PMN-PT Crystals forHigh Power Transducers
Jun Luo1, Sam Taylor1, Shujun Zhang2 and W. Hackenberger1
1

2

TRS Technologies, Inc, State College, PA 16801
Material Research Institute, Pennsylvania State University, PA16801
Email: jun@trstechnologies.com

The third generation of advanced relaxor-PT piezoelectric single crystals, Mn:PIN-PMN-PT (manganese
doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3), has attracted broad attention for the high powertransducers due to their greatly reduced mechanical loss but well-maintained, extremely highelectromechanical coupling coefficient. Small signal characterization of Mn:PIN-PMN-PT crystals havebeen extensively studied. However, systematic large signal tests of Mn:PIN-PMN-PT crystals were
urgently needed for further assessing the properties for high power transducer operation.
A systematic large signal, quasistatic measurement has been conducted for Mn:PIN-PMN-PT crystals
under variable prestress, temperature and electric field. Preliminarily optimized operation domains forhigh power transducer design have been revealed for [001]-poled crystals for achieving maximum
acoustic power density with low hysteretic losses caused by nonlinearity and phase transitions. It wasproved that the uniaxial prestress can stabilize the rhombohedral phase and suppress the electric field
induced phase transition. Furthermore, driven by a combination of a bipolar AC field and a positive DC
bias field, the crystals exhibit a broader range of linear strain and polarization response under uniaxial
prestress, which means, at room temperature, a positive DC bias field (applied in the same direction withthe poling field) expands the linear range of strain response under a bipolar AC field (1Hz). As shown in
Fig. 1, for a +4kV/cm DC bias, the crystal was driven by a 6kV/cm bipolar AC field with no domain
switch. A larger AC field driving range may benefit the high power transducer applications.

Fig. 1: S-E loops of a Mn: PIN-PMN-PT crystal sample measured under 10MPa prestress and
4kV/cm external DC bias: (a) for 1-15kV/cm bipolar fields and (b) for 1-6kV/cm bipolar fields

ISAF1-C2-3 ____________________________________________________________________________________________________________________

Effects of excess Bi on high-temperature dielectric andpiezoelectric properties of lead-free 0.75BiFeO3-0.25BaTiO3
ceramics
Jianguo Chen , Jinrong Cheng1
1School of Materials Science and Engineering, Shanghai University, Shanghai, People’s Republic of
China
Email: chenjianguo@shu.edu.cn

0.75BiFeO3-0.25BaTiO3 (BF-BT) ceramics with different excess Bi contents were prepared by solidstate reaction method. The effects of excess Bi content on the structure, dielectric and piezoelectric
properties of BF-BT ceramics were studied. XRD results indicated that the modified BF-BT ceramics
exhibited single perovskite structure with rhombohedral symmetry. The introduction of excess Bi in thesolid solutions showed positive effects on both dielectric and piezoelectric properties. The Curie
temperature Tc, dielectric constant  and loss tan (1 kHz), piezoelectric constant d33, and plannerelectromechanical coupling factor kp of BF-BT ceramics with 1 % excess Bi were 514 oC, 230, 440, 4.6%, 115 pC/N and 0.28, respectively. The piezoelectric constant d33, and planner electromechanicalcoupling factor kp of BF-BT ceramics with 1 % excess Bi were stable up to 450 oC, about 300 oC higher
than that of PZT-based ceramics. The combination of improved piezoelectric constant d33 andtemperature stability indicated that BF-BT ceramics with excess Bi were promising candidates for hightemperature and lead-free piezoelectric applications.

ISAF1-C2-4 ____________________________________________________________________________________________________________________

Novel high temperature BiFeO3-(K0.5Bi0.5)TiO3-PbTiO3
piezoceramics
Jim Bennett1, Andrew.J.Bell1, Tim.J.Stevenson1 and Tim.P.Comyn1
1Institute for Materials Research, University of Leeds, Leeds, UK
Email: pm07jb@leeds.ac.uk

There is currently a need for high strain piezoelectric actuators that are capable of operating under
extreme temperatures and pressures in applications such as aerospace, deep sea oil drilling and inchemical processing. PZT is currently the dominant piezoelectric ceramic material in actuators,
sensors and transducers, however, PZT has a restricted operating temperature.
Ceramics belonging to the (1-x-y)BiFeO3-x(K0.5Bi0.5)TiO3-yPbTiO3 system have been fabricated. X-ray diffraction was utilized along with PUND, strain-field, polarization-field and high temperatureelectrical measurements in order to characterize the new materials. The Curie temperatures, TC, of thecompositions presented far exceed those of PZT, coupled with piezoelectric coefficients in the regionof 152-225 pC/N. A link was found to exist between the c/a ratio of the tetragonal phase across the
MPB and TC.
This work also examines the extrinsic piezoelectric effect as a function of temperature using thepiezoelectric Rayleigh relations. The effects of composition upon intrinsic contributions, d33 and EC are
also detailed. The d33, intrinsic and extrinsic contributions of these materials were found to increase up
to 150 °C while adhering to the Rayleigh model. The composition with the highest room temperature d33
was found to have a Rayleigh coefficient of 58.83 x 10-18 (m2/V2), an order of magnitude increase
compared to La-doped BiFeO3-PbTiO3.
Ternary and psuedoquaternary systems have recently been subject to large amounts of researchas many of the possible binary systems have been explored. This has led to a raft of materials with
reported high piezoelectric coefficients; these are often electrostrictive or have limited operating
temperatures. This system shows that with only small amounts of a third end member such as potassium
bismuth titanate in BFPT, the electrical properties of a binary system can be drastically altered.

ISAF1-C2-5 ____________________________________________________________________________________________________________________

Clive Randall1, Dennis P. Shay1, Russell Maier1, Doo Hyun Choi2, Michael Lanagan3
1
Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA, 2Materials Science andEngineerign, The Pennsylvania State University, University Park, PA, USA, 3Engineering Science and Mechanics, The
Pennsylvania State University, University Park, PA, USA

Designing Dielectric Materials for High Power and Energy Density-a New Era for Capacitor Based
Applications

This paper will develop a rationale for new dielectric materials that are required for new hightemperature and high energy density capacitors. We will consider the voltage saturation issues innonlinear dielectrics, degradation, and breakdown processes. We will also consider the impact ofcoupled dipole mechanisms on energy density and power density behavior of selected dielectricmaterials . These new insights into high energy density capacitors could be applied to electrochemicaland hybrid capacitor designs.

PFM3
CLUB C
Monday, July 22 2013, 04:30 pm - 06:00 pm
Chair:

Patrycja Paruch
University of Geneva

PFM-C3-1 ______________________________________________________________________________________________________________________

Interplay of polarization dynamic and surface electrochemistry in ferroelectrics: from ionic transport tochaotic dynamics and fractal growth
S.V. Kalinin,1 A. Morozovska,2 and V. Shur3
sergei2@ornl.gov

3

1

The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory,
Oak Ridge, TN 37922

2

Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University,
620000 Ekaterinburg, Russia

Institute of Physics, National Academy of Sciences of Ukraine, 46, pr. Nauki, 03028 Kiev, Ukraine

Polarization switching in ferroelectric materials is inseparable from the screening processes, which in many cases
are realized by mobile surface ions. In this presentation, I will discuss experimental evidence for the existence andslow dynamics of these ions based on variable temperature Kelvin Probe Microscopy data, and present
experimental strategies for exploring the injection and ionic transport phenomena based on the time-resolved
KPFM. The nontrivial effects of the ionic dynamics on domain structure and dynamics in ferroelectric thin films
and crystals, including metastable nanoscale phase separated domain states, slow switching dynamics, andformation of fractal domains and chaotic dynamics during switching are discussed.
This work is supported by the Center for Nanophase Materials Sciences which is sponsored by the Scientific User
Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy

PFM-C3-2 ______________________________________________________________________________________________________________________

Nanoscale electrochemical diode in proton-exchanged LiNbO3Michele Manzo,1 Nina Balke,2Amit Kumar,2 Stephen Jesse,2 Sergei V. Kalinin,2Brian J. Rodriguez,3 and Katia Gallo1
1
2

Dept. of Applied Physics, KTH - Royal Institute of Technology, Stockholm, Sweden
The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak
Ridge, Tennessee, USA
3
School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
Email: manzo@kth.se

Gaining deeper understanding of nanoscale ionic transport in solid-state materials is a key aspect
towards more efficient energy harvesting, storage, and conversion devices, as well as progress in otherapplications, such as memristors and holographic memories. LiNbO3 (LN) is an artificial ferroelectric(widely used in the context of nonlinearity and electro-optics)xviii where such insights are furthermore
relevant for an even broader range of applications, encompassing also photonics. Through macroscopic
studies on LN crystals of different stoichiometry, a clear correlation of its electrical conductivity to thehydroxyl content has been established.xix However, such analyses are performed at high temperatures(400÷1000 K) where conductivity is associated with thermal-activated ionic mobility. On the other
hand, estimations at room temperature report extremely low values (10-18 mS/cm) and hence are usuallyassessed by indirect methods.
Here we present room-temperature
b)
a)
Inner
(PE
) PE
Inner
conductivity
measurements
on60
Z
congruent LN substrates in whichc-AFM
40
ON state
OFF state
LN
protons have been controllably
PE
d
PE
PE
20
introduced via selective periodic
PE
α Y
X
PE
proton-exchange (PE). The electrical
0
Vext
-10
-5
0
5
10
excitation was applied via a nanoscale
V (V)contact, by means of conductive
Fig.10 a) 3D sketch of the periodic PE:LN wedged sample with which
atomic force microscopy (c-AFM), on PE and LN regions were probed by c-AFM. b) Current flowing throughwedge-polished samples as in Fig.1a. the sample plotted as a function of the DC-bias voltage (Vext) applied toThis offered the direct assessment on the crystal (bottom electrode in 1a). Measurements performed at thethe mechanisms for ionic transport in center of the PE region.
LN, highlighting conductivity enhancements up to four orders of magnitude localized at the core of the
PE regions. Furthermore, a strongly unipolar response of the measured currents as a function of theapplied voltage was observed (Fig. 1b). The effect was modeled by the Butler-Volmer equationsxx andascribed to the interplay of both electrically-activated ionic transport of interstitial protons in the corePE region and surface nanoscale electrochemical reactions occurring at the c-AFM tip. This response
was also systematically compared to the one arising in LN and regions with much lower proton content.
The study presented in this work opens a new approach to investigate and engineer at the nanoscale theinterplay among ionic motion, electrochemical, and photochemical phenomena on ferroelectric surfaces.
Current (pA)3ext

PFM-C3-3 ______________________________________________________________________________________________________________________

Formation of Ordered and Disordered Nanodomain Chainsas a Result of Switching by Conductive Tipof Scanning Probe Microscope
Ievlev Anton 1, Shur Vladimir1, Neradovskiy Maxim1,
Morozovska Anna2, Eliseev Eugene2, and Kalinin Sergei3
1
Ferroelectric Laboratory, Ural Federal University, Ekaterinburg, Russia
2
Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine,
Kiev, Ukraine
3
The Center for Nanophase Materials Sciences and Technology Division,
Oak Ridge National Laboratory, Oak Ridge, TN, USA
Email: anton.ievlev@labfer.usu.ru
Formation of the domain chains under the action of electric field produced by conductive tip of scanningprobe microscope (SPM) has been studied in 20 m-thick z-cut plate of congruent lithium niobate.
Switching was carried out by bipolar triangular pulses with amplitude Usw ranged from 20 V to 100 V
and duration 250 ms. The chain period d ranged from 100 nm to 1 m. The uniform, ordered anddisordered nanodomain chains was created in different switching conditions.
Uniform chains of non-interacted domains appeared forswitching with periods above 300 nm (for Usw = 50V)
(Fig. 1a). Decreasing of the period led to change of thenanodomain chains types due to domain-domaininteraction. Weak interaction at shorter periods(300 nm >d > 250 nm) led to formation of the uniform
chains with larger first domain. Further decrease of theperiod to 150 nm led to formation of ordered anddisordered chains (Fig. 1c,d). At the periods below
150 nm the domain merging started (Fig. 1b). Moreoverthe strong influence of the temperature and humidity in
the SPM chamber on the chain parameters has been
revealed.
Experimental results were attributed to influence of the Fig. 11: Different types of nanodomain
residual depolarization field of older domain, which chains formed after local switching withdifferent parameters. (a) Uniform chain; (b)suppresses the domain growth at short distances andmerging of domains in the chain; (c), (d)stimulate nucleation at proper distance. The proposed intermittent switching in the chain.
model has been confirmed by calculation of the spatial
distribution of electric field in the vicinity of the isolated needle-like domain both by computer
simulation and analytically.
Equipment of the Center of Nanophase Material Science of Oak Ridge National Laboratory was used(project CNMS2012-113). The research was made possible in part by RFBR (Grants 13-02-01391-а, 1102-91066-CNRS-а), by Ministry of Education and Science (Сontract 14.513.12.0006).

PFM-C3-4 ______________________________________________________________________________________________________________________

Towards a Better Understanding of Lateral Piezoresponse ForceMicroscopy
Shiming Lei1,2, Ryan C. Haislmaier1, Tom T. A. Lummen1, Wenwu Cao2,3, Venkatraman Gopalan11Materials Research Institute and Department of Materials Science and Engineering, Pennsylvania State
University, University Park, Pennsylvania, USA
2
Condensed Matter Science and Technology Institute and Department of Physics, Harbin Institute ofTechnology, Harbin, People's Republic of China
3
Materials Research Institute and Department of Mathematics, Pennsylvania State University, University
Park, Pennsylvania 16802, USA
Email: sul46@psu.edu
Piezoresponse Force Microscopy (PFM) has been widely used for probing and imaging domain
structures of ferroelectric materials. In order to obtain a comprehensive information of probed polarmaterials, both vertical and lateral signals are necessary to be used. In this sense, it is of vital importanceto bridge the PFM signal correctly to the corresponding properties of the probed materials.
Our previous theoretical calculations systematically analyzed the mechanisms of lateral and vertical
PFM response for Lithium Niobate single crystal (LiNbO3)37. But for the realistic experimental signals,
they are always contaminated by the frequency-dependent background noise, which is inherent to theexperimental setup2. Jungk et al. proposed an effective treatment to recover vertical contrast. However,to our best knowledge, no effective background noise treatment has been proposed for the lateral signal
so far, which undoubtedly holds back the quantitative understanding of lateral PFM signals. Here we
reported an effort towards eliminating the background noise in the lateral PFM signal. The results after
this treatment showed an excellent agreement with theoretical calculations. In addition, the 90° lateral
PFM signal scanning across the anti-parallel LiNbO3 domain wall, which was dismissed as an artefact
before, is confirmed with repeatable results in the present effort.

37

Lei et al, "Origin of piezoelectric response under a biased scanning probe microscopy tip across a 180° ferroelectric domain
wall", PHYSICAL REVIEW B 86, 134115 (2012)2

Jungk et al, "Quantitative analysis of ferroelectric domain imaging with piezoresponse force microscopy", Appl. Phys. Lett.
89 163507 (2006).

PFM-C3-5 ______________________________________________________________________________________________________________________

Application of Atomic Force Acoustic Microscopy and UltrasonicPiezoelectric Force Microscopy to Characterization of BismuthBased Piezoelectric Ceramics
Ute Rabe, Leonardo Batista, Sigrun Hirsekorn
Fraunhofer Institute for Non Destructive Testing (IZFP), Saarbruecken, Germany
Email: Ute.Rabe@izfp.fraunhofer.de
The combination of ultrasonics with scanning force microscopy allows one to exploit the bending modesof Atomic Force Microscope (AFM) cantilevers for material characterization with a local resolution in
the nm range. In Atomic Force Acoustic Microscopy (AFAM) the resonances of the cantilevers
vibrating in contact with the sample surface are evaluated to image local elasticity qualitatively and/or
quantitatively. The contact resonances are furthermore used for contrast enhancement in UltrasonicPiezoelectric Force Microscopy (UPFM). In the framework of a European/Mexican project, Bismuthbased epitaxial thin films have been investigated and evaluated by different operation modes of an AFM(Fig. 1)38. Especially, dynamic modes in the ultrasonic frequency range such as AFAM and UPFM havebeen used. Ferroelectric materials have found many useful applications for example as sensors,
actuators, transducers, and memories. However, most of these materials are based on toxic elements,
e.g., Lead (Pb). With the new European regulations restricting the use of such toxic elements, the needarises for new materials which provide the same or better functional properties. These properties such as
piezoelectric constants, polarizability and high electromechanical coupling factors are mostly
determined by the microstructure and the arrangement of the ferroelectric domains.

Fig. 12: (a) AFM topography image, (b) AFAM amplitude image and (c) UPFM image of the same surface areaof a BiFeO3 thin film on SrTiO3 (100)1

The macroscopic properties of Bismuth-based, polarized bulk samples Na0.5Bi0.5TiO3 (NBT) and
0.94Na0.5Bi0.5TiO3-0.06 BaTiO3 (NBT-BT) were also examined. The piezoelectric activity wascharacterized by impedance and 3D laser vibrometer measurements. Furthermore, the Young’s modulus
and the shear modulus were calculated from the longitudinal and transverse wave sound velocities andthe density. Using these data and the geometrical parameters of the samples, the first thickness andradial resonance frequencies were calculated and compared to experimental spectra.

38

R. P. Fernandes, L. Batista, A. C. G. Castro, L. Salamanca-Riba, M. P. Cruz, F. J. Espinoza-Beltrán, S. Hirsekorn, U. Rabe,
J. Muñoz-Saldaña, G. A. Schneider, Mater. Res. Soc. Symp. Proc. Vol. 1477, DOI: 10.1557/opl.2012.1701 (2012).

ISAF Group 1 Posters
Forum Hall
Monday, July 22 2013, 01:00 pm - 04:30 pm

ISAF-P1A-1 ____________________________________________________________________________________________________________________

Ultrahigh superelastic and actuation strains in BaTiO3 crystals by
reversible electromechanical domain switching
Yingwei. Li1, Faxin. Li1,4 , Xiaobing. Ren3, Haosu. Luo5, Daining. Fang2
1

State Key Lab for Turbulence and Complex Systems, College of Engineering, Peking University,
Beijing, 100871, China

2

3

Department of Aeronautics & Astronautics, College of Engineering, Peking University, Beijing,
100871, China

Materials Physics Group, National Institute for Materials Science, Tsukuba, 305-0047, Ibaraki, Japan
4

HEDPS, Center for Applied Physics and Technologies, Peking University, Beijing, China

5

Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, China
Email: yingweili@pku.edu.cn

Superelasticity (SE), characterized by large recoverable hysteretic stress-strain curve, has been observedin shape memory alloys and other smart materials including the relaxor ferroelectrics via reversible
phase transformation, while it has rarely been realized in normal ferroelectrics. Theoretically, SE could
appear in polyaxial ferroelectrics via reversible ferroelastic domain switching but should be under a bias
electric field because different domains are by default energetically identical. Chaplya and Carman
realized SE under electromechanical loading by non-180o ferroelastic domain switching in Lead
Titanate Zirconate ceramics; however, influenced by the interaction between grains, SE was realized
only under large external preload bias electric fields and compressive stresses. In this work, by using
BaTiO3 crystal, we realized ultrahigh superelastic strain of up to 0.85% in a pre-poled BaTiO3 crystal
under uni-axial electromechanical loading. The superelasticity was realized under bias electric fields of
only 200V/mm during compression with the maximum stress at 15MPa. More importantly, it was
tunable by the applied electric field, making it very promising for advanced damping applications. In
addition, when keeping the compression and making unipolar electric fields cycling, an actuation strainof 0.93%, which is larger than the previous reported value of ~0.8% by Bucsu et al, was obtained at
800V/mm. These characteristics stem from the reversible 90o domain switching under the competitionof electrical and mechanical loading. A unified incremental switching criterion was proposed to depict
the domain switching process.

Fig 1. Principle of realization of superelasticity and actuation in a poled BTO crystal via reversible 90odomain switching under electromechanical loading (a-d), and the measured experimental results (e-f).

ISAF-P1A-2 ____________________________________________________________________________________________________________________

2D Ferroelectrics – Material for Future Memory Devices?
Vilgelmina Stepkova1, Pavel Marton1, Jiri Hlinka1
1

Department of Dielectrics, Institute of Physics, Academy of Sciences of the Czech Republic,
Prague, Czech Republic
Email: stepkova@fzu.cz

Ferroelectric materials are characterized by existence of spontaneous polarization, which can bereoriented by application of electric field. The dependence of polarization on electric field magnitude is
described by hysteresis loop in analogy to ferromagnets. Typically, ferroelectric structure splits into
domains – the regions which differ by the direction of spontaneous polarization. These properties givean opportunity to store information.
It is already well known that ferroelectric memory
devices have a variety of advantages, such as nonvolatility, low energy consumption, fast information
writing, large number of rewriting cycles, etc.
However, the already existing ferroelectric random
access memory (FeRAM) is not very popular
nowadays due to it's low density of information
arrangement, high cost and limited capacity.
Present work is devoted to the investigation ofrecently predicted new type of ferroelectric domain
walls, so-called “Bloch walls”39,40,41,42 in analogy toferromagnets. These walls are characterized bynonzero out of plane component (Pt) (see Fig.1),
which has an orientation perpendicular tospontaneous polarization. The idea for new type ofmemory devices lies in switching of this polarizationout of plane component within the wall, not wholedomain state, which requires much lower energy
loses and in principle allow higher density of
information arrangement.

Fig. 13: Variation of polarization P

within Bloch- and Ising-type domain
walls. The Bloch-type structure (a,b)
conserves the magnitude of the local
vectorial order parameter.

39

P. Marton, I. Rychetsky, and Jiri Hlinka, “Domain walls of ferroelectric within the Ginzburg-Landau-Devonshire
phenomenological model ”, Phys. Rev. B, vol. 81, p.144125, 2010.
40

J. Hlinka, V. Stepkova, P. Marton, I. Rychetsky, V. Janovec, and P. Ondrejkovic “Phase-field modelling of 1800 “Blochwalls” in rhombohedral BaTiO3”, Phase Transitions, vol. 84, p. 738-746, 2011.
41

V. Stepkova, P. Marton, and J. Hlinka “Stress-induced phase transition in ferroelectric domain walls of BaTiO3”, J. Phys:
Condens. Matter, vol. 24, p. 212201, 2012.
42

M. Teherinejad, D. Vanderbilt, P. Marton, V. Stepkova and J. Hlinka, “Bloch-type domain walls in rhombohedral BaTiO3”, Phys. Rev. B, vol. 86, p. 155138, 2012.

ISAF-P1A-3 ____________________________________________________________________________________________________________________

Electrostrictive effect of PMN-PT crystals
Fei Li1, Li Jin1, Zhuo Xu1, and Shujun Zhang1,2
1Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education andInternational Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China
2
Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802, USA
Email: ful5@mail.xjtu.edu.cn
For exploring high performance piezoelectric materials, researchers generally resort to theferroelectric phase transition regions in perovskite solid solutions, where the polarization can be easilychanged by external field, leading to high dielectric and piezoelectric responses. This approach,however, improves the piezoelectricity at the cost of thermal stability. In addition, over the developmentof last sixty years, there is limited space to enhance the piezoelectric activity through this method. The
electrostrictive effect, which is a critical factor for controlling the piezoelectric response inferroelectrics, on the other hand, has received limited attention. With the aim of searching alternative
approaches to enhance the piezoelectric response, the electrostrictive effect was studied inPb(Mg1/3Nb2/3)O3-PbTiO3 relaxor ferroelectric crystal, a representative high performance piezoelectricmaterial, with respect to orientation, temperature and composition. The electrostrictive coefficients Q11C ,C
Q12C and Q44
of PMN-xPT (x=0.25-0.37) crystals are found to be about 0.055, -0.024 and 0.020 m4 C-2*
respectively. The maximum and minimum Q33
is found to be along <001> and <111> directions, being

about 0.055 and 0.014 m4 C-2, respectively. The relation between piezoelectric and electrostrictive
effects is discussed for domain engineered PMN-xPT crystals. Based on this research, it is expected thatthe piezoelectric activity of relaxor-PbTiO3 crystals can be greatly enhanced by improving theirelectrostrictive coefficients to the typical level of classical perovskite crystals.
[001] oriented PMN-0.28PT[110] oriented PMN-0.28PT[111] oriented PMN-0.28PT
Fitting curves

0.5

Strain (%)

0.4

[001]

Q11

4

Q11

[111]

Q11

0.2

2

=0.053 m /C

[110]

0.3

@ 80 kV/cm

4

2

4

2

=0.024 m /C

=0.014 m /C

0.1
0.0
-0.3

-0.2

-0.1

0.0

0.1

2

0.2

Polarization (C/m )0.3

ISAF-P1A-4 ____________________________________________________________________________________________________________________

Formation of Nanodomain Structure in Front of Moving Domain
Wall in Proton Exchanged Lithium Niobate
Mikhail Dolbilov1, Vladimir Shur1, Ekaterina Shishkina1, Ekaterina Angudovich1, Andrey Ushakov1,
Pascal Baldi2, Marc P. De Micheli2, Emmanuel Quillier2
1

2

Feroelectric laboratory, Ural Federal University, Ekaterinburg, Russia
Laboratory of condensed matter physics, University of Nice Sophia-Antipolis, Nice, France
E-mail: mikhail.dolbilov@labfer.usu.ru

Formation and evolution of the bands with nanodomain structure in front of the moving domain wall werestudied in a field range in the congruent lithium niobate LiNbO3 single crystals modified by proton exchange(CLN-PE). PE method is a well-developed technique which can produce the surface layers with step profileof spontaneous polarization and refractive index43.
Continuous motion of the domain wall led to the smooth switching current was optically observed in CLNPE in contrast to CLN. This process was caused by formation of with nanodomain structures in front of thewall which was revealed by Raman confocal microscopy (RCM). The averaged width of the nanodomain
bands grew with increasing of the external field.
For switching in constant field the domain structure evolution strongly depends on the applied field value.
Three different types of evolution were obtained: 1) continuous growth of the hexagon domains at low field(21.0 kV/mm) (Fig. 1a); 2) formation and growth of the wide domain wall in medium field (21.5 kV/mm)(Fig. 1b); 3) growth of micro- and nanodomain ensembles in high field (22.0 kV/mm) (Fig. 1c). The discreteswitching being the origin of all obtained effects is caused by retardation of the depolarization field screening
in the crystal with the surface dielectric layer44. The fitting of the measured field dependence of thenanodomain front propagation allowed to extract the value of the threshold and activation fields.

Fig. 14: Domain structure evolution during switching in constant field:(a) 21.0 kV/m, (b) 21.5 kV/m, (c) 22.0 kV/m
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has been used.
The research was made possible in part by RFBR (Grants 13-02-01391-а, 11-02-91066-CNRS-а, 12-0231731-mol-а), by Ministry of Education and Science (Сontract 14.513.12.0006), by UrFU development
program.

43

M.P. De Micheli, Ferroelectrics, vol. 340, p. 49, 2006.

44

V.Ya. Shur, Journal of Materials Science, vol. 41, p.199, 2006.

ISAF-P1A-5 ____________________________________________________________________________________________________________________

Forming a regular domain structures at 127º Y’-cut of a LiTaO3
crystal by using direct e-beam writing
Evgeny Emelin1, Dmitrii Roshchupkin1, Sergey Lavrov2, Nikita Ilyin2, Andrey Kudryavtsev2
1

Institute of Microelectronics Technology and High-Purity Materials Russian Academy of
Sciences/Chernogolovka/Russian Federation
2
Moscow Institute of Radioengineering, Electronics and Automation/Moscow/Russian Federation
Email: EEmelin@iptm.ru
Regular domain structures (RDS) were formed at the 127º Y'-cut of a LiTaO3 crystal by direct e-beamwriting. The period of RDS was 2 and 10 μm. After e-beam writing process the optical contrast wasobserved at the irradiated surface without chemical etching and was stable for at least several months.
To visualize the formed domain structures two methods were used:
1) selective chemical etching in a HF+2HNO3 solution for 60 s at 110 ºC. In this case domains ofdiffering signs were revealed due to different etching rates on surface areas of opposite polarity45. Fig.1
shows both irradiated and opposite crystal surfaces after the etching process. As can be seen from Fig.1,
the reliefs formed on the irradiated and the back sides of the crystal after etching are shifted with respect
to each other. The domains distribution inside the 127º Y'-cut of a LiTaO3 occurs at the angle 37º to theirradiated surface;2) generation of the second harmonics of optic radiation on the RDS (Fig.2). This method enables
nondestructive study of the domain structure. The sensitivity of the method is sufficient to resolve thedomain structure lines. The domain lines consist of single domain of triangle shapes merged together(base-to-apex).

Fig.1. A regular domain structure inside the127º Y'-cut of LiTaO3 crystal with the period
2 µm.

45

Fig.2. Second harmonic generation of optic
radiation at the irradiated surface of 127ºY'-cut of LiTaO3 crystal. The period of
RDS was 10 μm.

O. Norio, I. Takashi, “Etching study of microdomains in LiNbO3 single crystals”, J. Appl. Phys., vol. 46, p. 1063, 1975.

ISAF-P1A-6 ____________________________________________________________________________________________________________________

Phase Transitions and Electrocaloric Effect in Ca modified
Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 Solid Solutions
Marija Dunce1, Eriks Birks1, Jani Peräntie 2, Juha Hagberg2, Maija Antonova1, Andris Sternberg1
1

Department of Ferroelectrics, Institute of Solid State Physics, University of Latvia, Riga, Latvia
2
Microelectronics and Material Physics Laboratories, University of Oulu, Oulu, Finland
Email: marija.dunce@cfi.lu.lv

Na1/2B1/2TiO3 (NBT) and its solid solutions attract interest mostly as an alternative for nowadays widely usedferroelectrics with high lead content, use of which is gradually limited due to environmental considerations.
According to our previous studies, composition 0.4NBT-0.4SrTiO3-0.2PbTiO3 is located in the region of the(T,x) phase diagram of 0.4NBT-(0.6-x)SrTiO3-xPbTiO3 solid solution where stability of relaxor state,evaluated as width of temperature region between the maximum of dielectric permittivity Tm and thetemperature of spontaneous phase transition between relaxor and ferroelectric states Tt, diminishes.

T ( C)In the present work dielectric properties, electric field-induced phase transitions and electrocaloric effect(ECE) are studied in 0.4NBT-0.4SrTiO3-0.2PbTiO3, if Sr in this composition is gradually replaced by Ca. At
low concentrations of Ca, stability of the phase transition temperature (Fig. 1) and polarization as a functionof Ca content, on the one hand, and steep200
decreasing of dielectric properties, on theTm (heating)other hand, is explained assuming that at
Tm (cooling)these concentrations Ca resides inside polar
150
nanoregions,stabilizingthemandTt (heating)preventing their reorientation in weakTt (cooling)100
external electric field, leaving thesurrounding media free from Ca.
50

Electric field-induced 1st order phasetransition between relaxor and ferroelectric0states is studied both by means criticalfields, obtained from double polarization-50
hysteresis loops, and ECE. Behaviour of
ECE at low Ca concentrations resembles
0.0
0.1
0.2
0.3
0.4
pure
0.4NBT-0.4SrTiO3-0.2PbTiO3,oyreaching value of 1.1 C at the electric fieldinduced phase transition. Like for Tt as a Fig. 15: Temperatures of maximum of dielectric
function of Ca content, remarkable permittivity Tm and spontaneous phase transition between
decreasing of the maximal value of ECE relaxor and ferroelectric states Tt as functions of Ca
starts at 15at% of Ca, while polarization at concentration y in 0.4NBT-(0.4-y)SrTiO3-0.2PbTiO3high electric field remains weakly dependent yCaTiO3, measured both on heating and cooling at 1 kHz.
on concentration up to 30at% of Ca.
Apparently decreasing of ECE indicates that concentration of polar nanoregions, which do not contribute to
ECE at the electric field-induced phase transition, increases at higher content of Ca.

ISAF-P1A-7 ____________________________________________________________________________________________________________________

X-Ray, Dielectric, Piezoelectric and Mossbauer Studies of
PbFe0.5Ta0.5O3 Multiferroic
A.V. Blazhevich1, I.P. Raevski1, M. S. Molokeev2, S.V. Misjul3, S.P. Kubrin1,
E.I. Sitalo1, S. I.Raevskaya1, V.V. Titov1, D.A. Sarychev1, M.A. Malitskaya1
1

Faculty of Physics and Research Institute of Physics,
Southern Federal University, Rostov-on-Don / Russia
2
Kirensky Institute of Physics, Siberian Branch of theRussian Academy of Sciences, Krasnoyarsk/ Russia
3
Institute of Engineering Physics and Radio Electronics,
Siberian Federal University, Krasnoyarsk/ Russia
Email: ablagh@gmail.com
X-ray, dielectric, piezoelectric, and Mossbauer studies of PbFe0.5Ta0.5O3 (PFT) powder and highlyresistive Li-doped PFT ceramics have been carried out. X-ray powder diffraction studies

Fig. 16: Temperature dependences ofd31 (pCoul/N)

 /1000

confirmed symmetry changes on cooling from cubic to tetragonal at 270 K and then to monoclinic at
220 K, reported earlier for PFT crystals46. Temperature dependence of the monoclinic angle exhibits ananomaly in the vicinity of mean temperature of the antiferromagnetic phase transition TN ≈ 180 K
determined from the temperature dependence of the doublet relative intensity η in the 57Fe Mossbauer
spectra2. Permittivity maximum is well below the
cubic-tetragonal transition and shows a strong75
frequency dependence (Fig.1) well described by a
Vogel-Fulcher law. This relaxor-like behavior seems
20
d31
to be due to coexistence of tetragonal and cubic
50
phases in a wide temperature range. This assumption
correlates with a plateau of piezoelectric modulus,
1025
within the range of tetragonal phase (Fig.1).

TN values of PFT powders and ceramics studied
varied from 120 to 190 K depending on the sintering
00conditions. This dependence may be attributed to the
100
200
300
3
changes in the degree of Fe clustering or Fe and Ta
Temperature (K)ordering.
dielectricThis study was partially supported by RFBR grant 12- permittivity ε measured at frequencies 102, 103, 104,08-00887.
105 and 106 Hz and piezoelectric modulus d31 forpoled Li-doped PFT ceramics.

46

N Lampis, P, Sciau, A.G. Lehmann, “Rietveld refinements of the paraelectric and ferroelectric structures of PbFe 0.5Ta0.5O3”, J.
Phys.:Condens. Matter., vol. 12, p. 2367–2378, 2000.
2

I. P. Raevski, S. P. Kubrin, S. I. Raevskaya, V.V. Stashenko, D. A. Sarychev, M. A. Malitskaya, M. A. Seredkina, V. G. Smotrakov, I.
N.Zakharchenko,V. V. Eremkin, “Dielectric and Mossbauer studies of perovskite multiferroics”, Ferroelectrics, vol. 373. p.121-126, 2008.
3

I. P. Raevski, S. P. Kubrin, S. I. Raevskaya, D. A. Sarychev, S. A. Prosandeev, M. A. Malitskaya, “Magnetic Properties of
PbFe1/2Nb1/2O3: Mossbauer Spectroscopy and First Principles Calculations”, Phys. Rev. B., vol. 85, p.224412-1 - 224412-5, 2012.

ISAF-P1A-8 ____________________________________________________________________________________________________________________

Linear and nonlinear optical properties of congruent LiNbO3
Arthur Riefer, Simone Sanna, Arno Schindelmayr, Wolf Gero Schmidt
Theoretische Physik, Universität Paderborn, Warburger Str. 100,
33100 Paderborn, Germany
Email: riefer@mail.uni-paderborn.de
Lithium niobate (LN) is one of the most important ferroelectric materials and the most important opticalmaterial. Recently, the linear49,50,51 and nonlinear5,52 optical properties of highly ordered stoichiometric LN(SLN) have been investigated theoretically. However, the technologically relevant material is thecongruently melting LN (CLN), containing up to 6% empty Li sites. In this work, we have investigated thelinear and the nonlinear optical properties of congruent LN from first-principles. Thereby CLN is simulated
both within the established Li and the Nb site vacancy models53 [in Fig. 1 denoted by CLN(Li) andCLN(Nb)]. Our approach allows us to calculate the dielectric function as well as the second harmonic
generation spectra within the independent particle approximation. The influence of the intrinsic defects on
the optical and electronic properties of LN is discussed. The results are compared with experimental
measurements1,2,54.

Fig. 17: Imaginary part of the ordinary and extraordinary dielectric function of SLN calculated within
the independent-particle approximation (IPA), including quasiparticle self-energy effects calculated
either within the GW approximation (GWA) or obtained from a scissors operator (Sci) and including
electron-hole attraction and local-field effects from the solution of the Bethe-Salpeter equation (BSE).
Also shown are IPA calculations for CLN and experimental data (solid line47, dashed line48).

47

E. Wiesendanger and G. Güntherodt, Sol. State Commun. 14, 303 (1974).

48

A. M. Mamedov, M. A. Osman, and L. C. Hajieva, Appl. Phys. A 34, 189 (1984).

49

W. G. Schmidt et al., Phys. Rev. B 77, 035106 (2008).

50

C. Thierfelder et al., phys. stat. sol. (c) 7, 362 (2010).

51

A. Riefer et al., IEEE Trans. on Ultrasonics, Ferroelectrics and Frequency Control 59, 1929 (2012).

52

S. Cabuk, Central European Journal of Physics 10, 239 (2012).

53

T. Volk et al., Lithium Niobate, Berlin Springer, 2008.

54

D.A. Roberts, IEEE J. of Quantum Electronics 28, 2057 (1992).

ISAF-P1A-9 ____________________________________________________________________________________________________________________

Dynamic Denisyuk holograms in photorefractive crystals:
fundamental physical properties and applications forinterferometry
Pavel V. Zuev1, Stanislav M. Shandarov1, Sergey S. Shmakov1, Nikolay I. Burimov1,
Bykov1, Alexander E. Urban, Yury F. Kargin2, Vasiliy V. Shepelevich3

Vitaly I.

1

Department of Electronic Devices, Tomsk State University of Control System andRadioelectronics, Tomsk 634050, Russia
2
Baikov Institute of Metallurgy and Materials Science Sciences of the RAS,
Moscow
119991, Russia
3
Department of Theoretical Physics, I.P. Shamyakin Mozyr State Pedagogical University,
Mozyr
247760, Belarus
Email: zuev.p.v@gmail.com
We report on adaptive interferometry based on dynamic reflection holograms in photorefractive crystals. The
basic physical principles of the interaction of two counterpropagating light waves on dynamic reflection
gratings formed in the Denisyuk scheme in photorefractive crystals due to the diffusion mechanism of thecharge transfer are considered. We analyze the nonlinear response relating to both phase (photorefractive)
and amplitude (absorption) components of the reflection grating. Along with conventional linear electrooptic effect the additional elasto-optic contributions to the phase grating induced by secondary phenomena
are taken into account. We consider two converse effects, piezoelectric and flexoelectric ones, as the causesof existence of the elastic-strain gratings in the electro-optic (photorefractive) crystals.
The peculiarity of reflection volume holograms, which formed by interaction of waves from visible region, isthe small spatial period assuming values about 100 nm55. In this case the reflection holograms areaccompanied by electric-field gradient may be as high as several TV/m2. It is shown that owing to converse
flexoelectric effect, these giant gradient values are capable of generation in photorefractive crystal theappreciable elastic strains. We have considered the contradirectional interaction between a strong stationaryreference wave and a weak phase-modulated signal wave on a reflection grating in the X-cut piezoelectric(electro-optic) crystals belonging to the point symmetry groups 23, 43m , 42m , 422, 622, and 222. . It was
shown that qualitative distinctions in photorefractive response induced by linear electro-optic effect and by
converse flexoelectric effect together with the elasto-optic one are exhibited at phase demodulation in an
adaptive interferometric setup utilizing interaction of two counterpropagating light beams on the reflection
holograms. Based on the experiments with such interaction in the (100)-cut Bi12TiO20:Fe,Cu crystals weestablished that theirs flexoelectric coefficient f11 can be estimated as the value in the range from 1.9 to 5.3
nC/m2.
This work was supported in part by the Russian Foundation for Basic Research (grant No 12-0290038_Bel_а), and by the Belarusian Republican Foundation for Fundamental Research (grant No F12R222).

55

S.M. Shandarov, S.S. Shmakov, N.I. Burimov, O.S. Syuvaeva, Yu.F. Kargin, and V.M. Petrov, “Detection of thecontribution of the inverse flexoelectric effect to the photorefractive response in a bismuth titanium oxide single crystal,”
JETP Letters, vol. 95, p. 699–702, 2012.

ISAF-P1A-10 ___________________________________________________________________________________________________________________

Modeling of switching and piezoelectric phenomena in PVDF
Vladimir Bystrov1,2, Ekaterina Paramonova2, Varsenik Gevorkyan3, Leon Avakyan3, Igor Bdikin4,
Robert Pullar1 and Andrei Kholkin1
1
2

Department Materials Eng. and Ceramics & CICECO, University of Aveiro, Aveiro, Portugal
Institute of Mathematical Problems of Biology, Rus. Academy of Sciences, Pushchino, Russia
3
Physics Faculty, Southern Federal University, Rostov-on-Don, Russia
4Centre for Mechanical Technology and Automation, University of Aveiro, Aveiro, Portugal
Email: vsbys@mail.ru , bystrov@ua.pt

At the present work we consider the molecular model of ferroelectric polymer polyvinylidene fluoride(PVDF) film, consisting from one, two chains [-CH2-CF2-]n and for PVDF unit cell. The main software wasHyperChem 8.0 for all models as for quantum calculations as well for molecular mechanics. First principle
calculations were employed, using various quantum-chemical methods (QM), including semi-empirical(PM3) and various density functional theory (DFT) approaches, and in addition combined with molecularmechanics (MM) methods in complex joint approaches (QM/MM). The first model, is limited by n= 6
elementary units CH2CF2. The first principle approach PM3 and molecular dynamic run were applied forinvestigation of the switching and its kinetics for these models. It is revealed, that kinetics of polarization
switching shows a homogeneous critical behavior with critical point at Landau-Ginzburg-Devonshire (LGD)
coercive field E = EC. Two types of 2 PVDF chains behavior were established: simultaneous andconsequence rotation in low and high electric field for two chains model. Our modeling and first principle
calculation for one chain model was obtained hysteresis loop for PVDF with LGD intrinsic coercive field EC~ 1 GV/m and for two chains it is confirmed with EC ~ 2…2.5 GV/m. These obtained results are comparedwith experimental data at the nano-scale level by the atomic force microscopy. These data are related alsowith arisen of the PVDF piezoelectric effects, especially of the negative piezoelectric coefficients. Performed
detailed molecular modeling was applied to study the nature of this negative piezoelectric effect in PVDF,
and these results confirmed by actual nanoscale measurements. Both PVDF molecular chains and a unit cellof crystalline -phase PVDF were modelled. This computational molecular exploration clearly shows thatthe nature of the so-called negative piezo-electric effect in the ferroelectric PVDF polymer has a selfconsistent quantum nature, and is related to the redistribution of the electron molecular orbitals (wavefunctions), leading to the shifting of atomic nuclei and reorganization of all total atomic charges to the new,energetically optimal positions, under an applied electrical field. As a results, complex cooperative dipole
reorganization occurs on the bonded molecular chain under the action of this applied electrical field.
Complicated non-uniform and nonlinear anisotropy deformations in the PVDF molecular chain result,involving both individual interactions of C2H2F2 dipoles, as well as the whole PVDF unit cell, leading tonegative deformation in relation to the applied field. Molecular modeling and first principles calculations
show that the piezoelectric coefficient d33 has negative values in the range d33 ~-16.5…-33.5 pC/N (pm/V),
corresponding to known data, and allowing us to explain the reasons for the negative sign of the piezoresponse. For value of we obtained a value of another oriented coefficient d31 ~ +15.5 pC/N (with apositive sign). This computational study is corroborated by measured nanoscale data obtained by atomic
force and piezo-response force microscopy (AFM / PFM). This study could be useful as a basis for further
insights into organic and molecular ferroelectrics.

ISAF-P1A-11 ___________________________________________________________________________________________________________________

Dielectric properties of ferroelectric thin films with full and partial
depletion and the possible inversion of the thickness effect in thepresence of impurities
I. B. Misirlioglu, M. Yildiz
Faculty of Engineering and Natural Sciences, Sabancı University, Istanbul, Turkey
Email: burc@sabanciuniv.edu
Interfaces in ferroelectric structures are important not only because these are the boundaries at which theregular structure of the crystal terminates but also because of the termination of the polar arrangement
and nature of the contact with the electrodes if the system is electroded. Therefore, the treatment offerroelectrics as polar semiconductors becomes inevitable when examining polarization stability anddielectric properties especially in reduced dimensions. In this work, we study the effect of electricalboundary conditions on ferroelectrics in thin film form and possible scenarios in case the ferroelectrichas moderate to high densities of vacancies or impurities. Our recent findings reveal the extent ofcoupling between the dielectric response and depletion charges and how depletion charges alter theCurie point in fully and partially depleted films, a phenomena often neglected in discussing size effects
in films. The possibility that high densities of depletion charges might invert the thickness effectconcerning the stability of polarization in ferroelectric films is demonstrated where thicker films have ahigher dielectric response with respect to thinner ones for the same impurity density (Fig. 1). We also
investigate the effect of line defects on depletion charge and impurity distribution as a function of film
thickness to shed light on the possible impact of line defects on leakage currents in ferroelectric thinfilms.

Fig. 1: Computed thickness dependence of the small signal dielectric response at zero bias for BaTiO 3
sandwiched between Pt electrodes on SrTiO3 as a function of impurity density 56. The lines are guides
for the eyes.

56

I. B. Misirlioglu, M. Yildiz, “Dielectric response of fully and partially depleted ferroelectric thin films and inversion of the thickness
effect”, J. Phys. D: Appl. Phys., vol. 46, p.125301-11, 2013.

ISAF-P1A-12 ___________________________________________________________________________________________________________________

Influence of the piezoelectric effect on
ferroelectric properties and phase transition
Andreas Leschhorn1 , Herbert Kliem1
1Institute of Electrical Engineering Physics, Saarland University, Saarbruecken, Germany
Email: a.leschhorn@lusi.uni-sb.de

The Weiss model for magnetization can also be applied to the polarization of ferroelectrics 57. In thismodel, the local field is the superposition of the applied field Ea and of a field proportional to thepolarization P:(1)
The coupling parameter α describes the coupling between the dipoles by the electrostatic fields. The
dipoles with moment p are assumed to fluctuate thermally activated in double well potentials yielding(temperature T, dipole density n)
(

)

(2)

With (1) and (2) we have a feedback loop for the polarization. In this form the model predicts several
properties of ferroelectric materials like the polarization hysteresis and the phase transition fromferroelectric to paraelectric at the Curie temperature. However, the model only yields a ferro- toparaelectric transition of the second type.
The type 2 transition can be converted into a type 1 transition by introducing the piezoelectric effect58.
Simultaneously the single hysteresis of polarization splits into a double hysteresis loop close to the Curie
point.
With the piezoelectric effect the distances inside the sample depend on the polarization. In this way
some parameters in (1) and (2) are functions of P, namely the dipole moment p, the density n and thecoupling parameter α. If the length of the sample is changed due to the polarization the distances
between the dipoles are altered and e.g. the coupling constant α is also varied like (piezo coefficient
ς)
( )

(

)

(3)

Combining (1), (2) and (3) yields the ferro- to paraelectric transition of the first order. In an analogous
way also the variation of p and/or n with the polarization P can cause this change from type 2 to type 1
transition.
Acknowledgement: This work is supported by the Deutsche Forschungsgemeinschaft.

57

J. C. Burfoot , G. W. Taylor, “Polar Dielectrics”, MacMillan Press, London, 1979.

58
H. Kliem, , “Strain induced change from second order to first order ferroelectric phase transition”, Ferroelectrics,
vol. 425, p. 54-62, 2011.

ISAF-P1A-13 ___________________________________________________________________________________________________________________

Modeling and Numerical Study of Electroacoustic Behavior of
Lithium Niobate Under an Initial Electrical Stress
Domenjoud Mathieu1, Lematre Michaël2, Fortineau Jérôme2, Feuillard Guy2 and Tran-Huu-Hue LouisPascal2
1

GREMAN, UMR CNRS 7347, University of Tours, Tours, France
2
GREMAN, UMR CNRS 7347, ENIVL, Blois, France
Email: mathieu.domenjoud@univ-tours.fr

Piezoelectric materials are frequently used for various applications, such as sensors, actuators ortransducers, many of which imply operation under harsh environmental conditions like hightemperature, high pressure, external electrical DC bias field or mechanical stress. For instance, Tonpilz
piezoelectric transducers are built in such a way that a stress-bolt assembly maintains the piezoelectric
stacks under compression, leading to an increased efficiency and lifetime. Conversely, in high power
ultrasonic transducers used for therapy, the electroacoustic response can be improved by applying astatic electrical field. However, the presence of high external (mechanical or electrical) stress induces
non-linear effects that significantly modify the piezoelectric characteristics through a shift of material
properties from their stress-free values. The improvement of electromechanical performance due toexternal prestress is not very well known and designers of systems, who have to deal with difficulties toevaluate piezoelectric material properties in real operating conditions, often rely on empiricalconsiderations.
Recently, we developed a second order formalism of piezoelectric structures under an external(mechanical or electrical) stress in the natural (nondeformed) and current (predeformed) coordinate
systems59. Here, our formalism is used to evaluate the effect of an applied electrical stress on theelectroacoustic behavior of piezoelectric materials. Knowing the coercitive field of lithium niobatematerial, we numerically quantify nonlinearities induced by an electrical prestress on the deformations,wave velocities and coupling coefficients for a lithium niobate plate. Evolutions of these parameters arestudied in the two coordinate systems as a function of the azimuthal and elevation angles as well as
electrical prestress values.
We show that the contribution of nonlinearity to deformation reaches 22.5% in a specific cut
plane. Moreover, the maximum shift in wave velocities induced by prestress is found to be 33 and 9 m/s
for quasi-longitudinal and quasi-transversal modes respectively. Numerical studies of electromechanicalcoupling coefficients show that the electrical prestress is able to produce an increase of about +1.1%.
Finally, we show that electrical prestress in specific cut planes significantly increases longitudinal wave
velocities and electromechanical coupling coefficients. This study shows that, by designing an electricalprestressed transducer using a piezoelectric material in well determined cuts, it is possible to increase theperformance and that this can be predicted.

59

M. Lematre, M. Domenjoud and L. P. Tran-Huu-Hue, “Exact second order formalism for the study of electro-acoustic
properties in piezoelectric structure under an initial mechanical stress”, Ultrasonics, vol. 51, p 898-910, 2011.

ISAF-P1A-14 ___________________________________________________________________________________________________________________

The abnormal polarization switching of relaxor terpolymer films at low
temperature
B. B. Tian, X. L. Zhao, B. L. Liu, J. L. Wang, J. L. Sun, X. J. Meng and J. H. Chu
1State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academyof Sciences, Yu Tian Road 500, Shanghai 200083, China

Abstract
The ferroelectricity of the Poly(vinylidene fluoride-trifluoroethylene-chlorofloroethylene) terpolymer
films fabricated by the Langmuir–Blodgett (LB) technology were investigated from 180 to 300 K. The
temperature dependence of the remanent polarization and the dielectric response shows a broad peak at~ 270 K, suggesting a ferroelectric phase transition. Contrary to the perovskite relaxor, a deviation from
the Merz’s law is observed in the relation between the coercive field and frequency for the relaxor
terpolymer. The particular ferroelectricity of the relaxor terpolymer is considered to be associated withthe distinct structure and the dynamics of its typical molecular conformations.

ISAF-P1A-15 ___________________________________________________________________________________________________________________

Effect of grain size on the microwave dielectric properties of βBZN ceramics
Gao-qun Zhang1, Hong Wang1, Di Zhou1, Jing Guo1
1

Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education,
Xi’an Jiaotong University, Xi’an 710049, China
Email: gaoqunzhang2012@gmail.com

In this study, β-BZN ceramics were prepared by the traditional solid state method. The samples sinteredat 930 oC for 2 h possessed a relative permittivity of 74 and a Q×f value of 3740 GHz. The grain size ofβ-BZN ceramics was regulated by changing sintering temperature and heat preservation time. When thesintering temperature was increased from 780 oC to 990 oC, the grain grew from 0.7 um to 1.9 um as
approximate exponential function. Grain growth mechanism of β-BZN ceramic with sintering
temperature was discussed. The functionln 1000  l 3p t   3e

T 1000 3

about the relationship between the grain size of β-BZN and sintering temperature was obtained bysimulation, whose results were in accord with experimental values. For the samples at different heat
preservation time, there was deviation between experimental values and results from theory model
formulaG 2  G02  Ct .

For well dense β-BZN, the grain size has little effect on the relative permittivity. And the Q×f value
increased with increasing grain size from 0.7 um to 1.2 um, but for β-BZN ceramics of the average grain
size above 1.2 um, the Q×f value decreased. When the grains grew from 0.7 um to 1.2 um, there was auniform microstructure, and a reduction in the number of grain boundaries per unit volume would resultin material with a lower loss. When the average size of the grains was more than 1.2 um, some large
grains appeared, which introduced more defect and deteriorated the quality factor.

ISAF-P1A-16 ___________________________________________________________________________________________________________________

Density Functional Theory Calculations of
Doped
Perovskite Barium Titanate (BaTi0.6Nb0.2Fe0.1O3): Structural
Deformations and Ferroelectric Properties
Piyarat Nimmanpipug1,2, Wiranwit Wankawee1, Laongnuan Srisombat1,2,
Laosiritaworn1,2

Yongyut

1

FacultyComputational Simulation and Modelling Laboratory (CSML), Department of Chemistry,of Science, Chiang Mai University, Chiang Mai 50200, Thailand

2

Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education,
10400, Thailand

Bangkok

Email: piyarat.n@cmu.ac.th, piyaratn@gmail.com
The structural deformations and ferroelectric properties of doped barium titanate were theoreticallyanalyzed using density functional theory (DFT). Niobium (Nb5+) and ferrous (Fe2+) ion were substituted
in all possible titanium sites to evaluate all possible structures. The distortion of octahedral hole wasfound depending on size of dopant and neighboring atoms. The direction of atomic displacement inoctahedral holes were investigated and related to the direction of polarization. The splitting of phononmodes was observed in doped barium titanate indicating ferroelectric instability of the structure. The
electronic band structure and density of states (DOS) indicate decrease of energy band gap in doped
structures. The hybridization of the Ti-3d, Nb-4d and Fe-3d with the O-2p orbitals was remarked
corresponding with the shift in the frequency of phonon modes.

ISAF-P1A-17 ___________________________________________________________________________________________________________________

Free energy of BaTiO3 single crystal
Raphaël Renoud1, Mostafa Ragheb1, Gilles Damamme2, Caroline Borderon1, Hartmut Gundel1
1

2

IETR, University of Nantes, Nantes, France
CEA/DAM, centre de Gramat, Gramat, France
E-mail: raphael.renoud@univ-nantes.fr

The thermodynamic description of a ferroelectric material is generally done using the approach ofLandau. This latter is based on the development of the free energy around the para/ferro-electrictransition temperature. Following the formulation of Devonshire (1949) [1], many authors have tried to
improve the description level. In this context, the free energy due to the elastic behavior of the material
has been included in models. In the case of BaTiO3, for example, we can hold work of Li et al. [2], Bell[3] or Wang et al. [4]. Despite this progress, the development of the free energy in successive power ofthe polarization still depends on parameters that must be set in an ad hoc manner. We propose here aformulation of the free energy for displacive ferroelectrics which takes direct account of the polarization
but also of the coupling with temperature and of the electrostrictive coupling. We apply this formalism
to the case of BaTiO3 single crystal. A comparison with experiment and with previous works [2-4] isperformed. The proposed approach allows for example to properly account for the evolution of the
spontaneous polarization [5-6] and lattice parameters [7] as a function of temperature in all polar phases.
4,04

0,40

c

Lattice parameter (Å)

Tetragonal

0,35
Orthorhombic-2

Pz (C·m )0,30
Rhombohedral

0,25
0,20
0,15
Wang
Bell
Li

0,10
0,05
0,00

Merz, Wieder
ModèleKay 1949

4,03
4,02

c

4,01
a=b=c

4,00
a=b

3,99
a=b

3,98

Rhombohedral
Orthorhombic

0

50

100

150

200

250

300

350

400

450

T (K)

Fig. 1: Spontaneous polarization Pz as a function of
the temperature T. Comparison of the modelwith the approach of Li et al. [2], Bell [3] andWang et al. [3]. Comparison with experimental
data of Merz [5] and Wieder [6]Tetragonal

Cubic

3,97
0

50

100

150

200

250

300

350

400

450

T (K)
Fig. 2: Lattice parameter as a function of thetemperature. Comparison of the model withexperimental data of Kay and Vousden [7][1] A.F. Devonshire, Phil. Mag. 40 (1949) 1040
[2] Y.L. Li, L.E. Cross, L.Q. Chen, J. Appl. Phys. 98 (2005) 064101[3] A.J. Bell, J. Appl. Phys. 89 (2001) 3907
[4] Y.L. Wang, A.K. Tagantsev, D. Damjanovic, N. Setter, V.K. Yarmarkin, A.I. Sokolov, I.A. Lukyanchuk,
J. Appl. Phys. 101 (2007) 104115[5] W.J. Merz, Phys. Rev. 91 (1953) 513[6] H.H. Wieder, Phys. Rev. 99 (1955) 1161
[7] H.F. Kay, P. Vousden, Phil. Mag. 40 (1949) 1019

ISAF-P1A-18 ___________________________________________________________________________________________________________________

Ferroelectric domain engineering in tricolour superlattices
C. Hubault1,5, I. C. Infante2, A. Boulle3, N. Boudet4,C. Davoisne5, L. Dupont5, V. Demange6, A. Perrin6,
B. Gautier7, M.G. Karkut1 and N. Lemée1*
1

LPMC, Université de Picardie Jules Verne, Amiens, France
2

SPMS, CNRS UMR 8580, Ecole Centrale Paris, France
3

4

SPCTS, CNRS UMR 7315, Limoges, France

D2AM-CRG, ESRF and Institut Néel, CNRS, Grenoble, France
5

LRCS, CNRS UMR 7314, Amiens, France

6
7

USCR, CNRS UMR 6226, Rennes, France

INL, CNRS UMR 5270, INSA, Villeurbanne, France
Email: nathalie.lemee@u-picardie.fr

Functional properties of perovskite ferroelectric thin films are highly influenced by their domain
structure which is determined both by epitaxial strain and depolarizing fields. Ferroelectric superlattices
can provide a way to disentangle the competition between the elastic and electrostatic energy. Recently
we have applied tensile in-plane strain to PbTiO3 (PT) by combining PT, PbZr0.2Ti0.8O3 (PZT 20-80) andSrTiO3 (STO) in tricolour superlattices60. In bicolour PT/PZT 20-80 SLs, an a/c polydomain structure
was evidenced61. In tricolor PT/STO/PZT superlattices, the introduction of ultrathin layers of STO (2-3unit cells) between each ferroelectric layer seems to play a significant role in the decoupling of
ferroelectric interactions. Indeed, the insertion of STO layers induces a strong decrease in thetetragonality of the overall superlattice, and inhibits this 90° polydomain formation. X-ray diffraction
measurements evidence the presence of satellites around the out-of-plane SL Bragg peaks. This
modulation is characteristic of 180° ferroelectric domains of alternate “up” and “down” polarization,
presumably produced to minimize the electric field arising from the STO induced depolarizing field.
Their polar origin is clearly confirmed by their disappearance close to the superlattice ferroelectrictransition temperature. In order to investigate the in-plane polar structure, reciprocal space maps wererealized using grazing incidence diffraction at beamline BM2-D2AM at ESRF. The period  of theobserved satellites is consistent with the polar modulation measured around the specular reflections.
These measurements show that in the tricolour PT/STO/PZT 20-80 superlattices the polarization has
both in-plane and out-of-plane components, which is an argument in favour of a polarization rotation
away from the normal. Using piezo-force microscopy, it is possible to write and image polarization
domains, confirming that the piezoelectric response of the sample is still retained with the 180°
nanodomain formation. This work demonstrates that such tricolour ferroelectric superlattices provide a
powerful tool to study the role of electrostatic and strain effects in the control of polarization orientation.

60

C. Hubault et al., J. Appl. Phys., vol. 112, 114102, 2012

61

C. Hubault et al., Appl. Phys. Lett., vol. 99, 052905, 2011

ISAF-P1A-19 ___________________________________________________________________________________________________________________

Modeling of Glycine polymorphic and switching properties
Vladimir Bystrov1, Ensieh Hosseini1, Igor Bdikin2, Svitlana Kopyl2 and Andrei Kholkin1
1

Department Materials Eng. and Ceramics & CICECO, University of Aveiro, Aveiro, Portugal
2
Centre for Mechanical Technology and Automation, University of Aveiro, Aveiro, Portugal
Email: bystrov@ua.pt

Polymorphism of glycine nano-crystal structure is known – it could exist in and in several casesas modification. The most interest for nano-electronic present non-centro-symmetric structures: glycine (space group P21) and -glycine (space group P32). These structures reveal piezoelectric andpolar properties. But the value of polarization is not clear as well its switching behaviour. In this work
computational modelling of both glycine
polymorphic crystal structures were
performed using combined method with
LDA first principle calculations ofatomic optimized crystal structures on
Linux cluster and with molecular semiempirical calculations by HyperChem
8.0 software.
Figure show both
molecular nano-crystal structures in two
projections with hydrogen bonds net andtotal dipole. The main difference forthese strictures consist that for -glycine
we have very strong oriented along OZ
axis hydrogen-bonded net with total
dipole moment preferably oriented inthis direction. Computed value ofpolarization by PM3 method is P ~ Pz =0.17 C/m2. But for the glycine we Figure: Computed molecular models of two polymorphic
have layered structure with hydrogen glycine structures:-glycine and -glycine.
bonds in XOZ plane, while total dipole
moment has several components and polarization is oriented under angle to main axis. Computed valuesof polarization components are smaller and have average P ~ 0.025 C/m2. The orientation of polarization
vector could provide several components (Pz, Py, Pz) and piezo-response, while glycine could have
only Z-component. Estimation of coercive electric field for -glycine have high value Ec ~ 3 GV/m = 30
MV/cm, oriented along OZ axis, and it made non-possible polarization and piezo-response switching inthis case. For glycine we obtain 10 times less value of coercive electric field Ec ~ 0.4 GV/m = 4
MV/cm for different polarization components, which make possible for switching phenomena. For theseestimations we use value of dielectric permittivity for glycine ~ 6. These computed data and obtained
switching properties for both models of and glycine polymorphic structures are confirmed by
AFM/PFM measurements. As result, we can conclude that namely glycine could demonstrate
ferroelectric properties.

ISAF-P1A-20 ___________________________________________________________________________________________________________________

Domain Kinetics in Lithium Niobate Single Crystals
Inhomogeneously Modified by Annealing in Vacuum
Alikin Denis, Pryakhina Victoria, Shur Vladimir, Negashev Stanislav, Palitsin Ilya
Ferroelectric laboratory, Institute of the Natural Science, Ekaterinburg, Russia
Email: denis.alikin@labfer.usu.ru
It is known that annealing of the lithium niobate (LN) crystals in vacuum leads to sufficient increase of thebulk conductivity caused by out-diffusion of oxygen ions62. We present experimental study of thepolarization reversal in the single crystalline plates of congruent LN annealed in vacuum in different
temperature-time regimes: 300oC, 1h, 300oC, 10 h and 850oC, 15 min.
The polarization reversal was carried out by
application of electric field using liquid electrolyte(aqua solution of LiCl). Instantaneous domain
patterns were in situ visualized by polarized optical
microscope (Carl Zeiss LMA 10, Germany). The
static domain patterns revealed by chemical etchingwere
observedbyopticalmicroscopy.
Nondestructivehighresolution
domainvisualization was achieved by piezoresponse force
microscopy and Raman confocal microscopy (NTMDT NanoLaboratories NTEGRA Aura and
NTEGRA Spectra, Russia).
Annealing at 300oC during 1 h didn’t change thedomain kinetics remarkably. The annealing at theFig.1. Domain kinetics in vacuum annealed lithium
same temperature during 10 h leads to domain
niobate (850 °C, 15 min). Time form the beginningkinetics with formation of the residual domains andof the pulse: (а) 48.8 s, (b) 51.6 s, (c) 53.2 s, (d)traces of the domain walls typical for modification
53.6 s.
of the thin surface layer 63.
Annealing at high temperature (850oC) drastically modified the domain kinetics and leads to smoothisotropic motion of the domain walls in the bulk (Fig. 1). The stable domain structure with charged domain
walls appeared over the whole switched area. The obtained switching in the bulk and isotropic domain
growth was attributed to inhomogeneous field distribution caused by inhomogeneous bulk conductivity.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has been used.
The research was made possible in part by RFBR (Grants 13-02-01391-а, 12-02-31377, 11-02-91066-CNRSа), by Ministry of Education and Science (Сontract 14.513.12.0006).

62

P.F. Bordui, D.H. Jundt, E.M. Standifer, R.G. Norwood, R.L. Sawin, J.D. Galipeau, “Chemically reduced lithium niobate single crystals:
Processing, properties and improved surface acoustic wave device fabrication and performance“, Appl. Phys, vol. 85, p. 3766 – 3769, 1999
63

D.O. Alikin, V.Ya. Shur, V.I. Pryakhina, N.V. Gavrilov, M. Carrascosa, J. Olivares, The Domain Kinetics in Congruent Lithium Niobate
Modified by Low and High Energy Ion Irradiation, Ferroelectrics, vol. 441, p. 17-24, 2012

ISAF-P1A-21 ___________________________________________________________________________________________________________________

Polarization Reversal Process in Lithium Niobate Single
Crystals with Photoresist Dielectric Layer
Shur Vladimir1,2, Akhmatkhanov Andrey1,2, Baturin Ivan1,2, Zorikhin Dmitriy1,2, Chuvakova Mariya1,
Lukmanova Almira1, Zelenovskiy Pavel1, Neradovskiy Maxim1.
1

Ferroelectrics laboratory, Ural Federal University, Ekaterinburg, Russia
2
Labfer Ltd., Ekaterinburg, Russia
Email: ahmathanov@labfer.usu.ru

The creation of the tailored periodic domain structure in lithium niobate (LiNbO3, LN) single crystals is
widely used technique for efficient conversion of the laser light frequency based on quasi-phasematching effect. The regular domain structure in LN is usually created by application of inhomogeneous
external electric field through the photoresist mask using liquid electrodes. Thus the study of domain
kinetics in LN covered by photoresist film is of the great practical importance for developing themethods of domain engineering.
The domain structure evolution during polarization reversal has been investigated in congruent LN(CLN) single crystals covered by photoresist dielectric film. The films with thickness ranged from 0.5 to
5.5 μm of positive (AZ-series) and negative (nLOF) photoresist were spin coated on Z+ polar CLN
surface. The polarization reversal process has been studied by in situ optical visualization of the domain
kinetics and analysis of the switching current data
It was revealed that the domain structure evolution changes drastically for film thickness about 2 m. The
conventional growth of hexagonal domains by jump-like motion of the plane domain walls oriented
along Y crystallographic directions accompanied by isolated pulses of switching current was observed
for film thickness below 2 m. In contrast the continuous domain wall motion and the smooth current
shape have been revealed for film thickness above 2 m caused by formation of the isolated
nanodomains in front of the moving domain wall.
The experimental switching current data was successfully fitted by Kolmogorov-Avrami formulamodified for switching in linearly increasing electric field in finite mediaxxi. Two stages of the switchingprocess representing ”continuous nucleation” and “growth only” processes revealed by fitting of theswitching current data were confirmed by in situ observation of the domain kinetics.
The complex study of the obtained static domain structures by optical, scanning probe and Raman
confocal microscopy allowed to reconstruct the unusual domain evolution scenario during polarization
reversal in CLN covered by thick photoresist film. The obtained results are important for creation of theperiodically poled CLN crystals.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has been used.
The research was made possible in part by RFBR (Grants 13-02-01391-а, 11-02-91066-CNRS-а), by
Ministry of Education and Science (Сontract 14.513.12.0006), by OPTEC LLC and in terms of Ural Federal
University development program with the financial support of young scientists.

ISAF-P1A-22 ___________________________________________________________________________________________________________________

Structural, elastic, and vibrational properties of Topological Insulatorson A2 5B36 compound based
H. Koc64, Amirullah M. Mamedov2, Ekmel Ozbay2
1
2

Department of Physics, Siirt University, 56100 Siirt, Turkey
Nanotechnology Research Center (NANOTAM), Bilkent University, 06800 Bilkent, Ankara, Turkey
Email: mamedov@bilkent.edu.tr

We have performed a first principles study of structural and elastic properties of rhombohedral Sb2Te3
and Bi2Te3 compounds using the density functional theory within the local density approximation. The
lattice parameters, bulk modulus, and its pressure derivatives of considered compounds have been
calculated. The second-order elastic constants have been calculated, and the other related quantities suchas the Young’s modulus, shear modulus, Poisson’s ratio, anisotropy factor, sound velocities, Debye
temperature, and hardness have also been estimated in the present work. The phonon dispersion curves
are derived using the direct method. The present results demonstrate that this compound is dynamicallystable.

Fig. 1: Energy band structure for Sb2Te3 and Bi2Te3. The calculated electronic band structure shows that Sb2Te3
and Bi2Te3 compounds have an direct band gap with the value 0.093 eV and 0.099 eV, respectively.

64

H. Koc, E. Deligöz, Amirullah M. Mamedov, “The elastic, electronic, and optical properties of PtSi and PtGe compounds”
Philophical Magazine, Vol. 91, p. 3093-3107, 2011.

ISAF-P1A-23 ___________________________________________________________________________________________________________________

Linear and Non-Linear Optical Properties of AgBO3(B=Nb, Ta):First Principle Study
Sevket Simsek, Amirullah M. Mamedov, Ekmel Ozbay
Nanotechnology Research Center (NANOTAM), Bilkent University 06800, Bilkent, Ankara, Turkey
Email: mamedov@bilkent.edu.tr
The linear and nonlinear optical properties of ferroelectrics AgBO3 (B=Ta, Nb) are studied by density functional
theory (DFT) in the local density approximation (LDA) expressions based on first principle calculations without
the scissor approximation. Specially, we present calculations of the frequency- dependent complex dielectric
function    , and the second harmonic generation response coefficient  (2) (2, ,  ) over a large frequency
range in rhombohedral phase for the first time. The electronic linear electrooptic susceptibility  (2) (, , 0) is
also evaluated below the band gap. These results are based on a series of the LDA calculation using DFT. Our
goals are to give the details of the calculations for linear and nonlinear optical properties, including the linear
electro-optic (EO) tensor for some ABO3 structures with oxygen octahedral structures using first-principles
methods65, 66.

65

S. Cabuk and S. Simsek, “First-principles calculation of the linear and nonlinear optical properties of LiTaO3”, Phys. Scr.,
Vol. 81, p. 055703-055710, 2010.
66
H. Akkus, Amirullah M. Mamedov, “Linear and Nonlinear Optical Properties of SbSI: First-Principle Calculation”,
Ferroelectrics, Vol. 352, p.148–152, 2007.

ISAF-P1A-24 ___________________________________________________________________________________________________________________

One and Two-Dimensional Ferroelectric LiNbO3 Photonic Crystal
Sevket Simsek, Amirullah M.Mamedov, Ekmel Ozbay
Nanotechnology Research Center (NANOTAM), Bilkent University 06800, Bilkent, Ankara, Turkey
Email: mamedov@bilkent.edu.tr
In this report, we present an investigation of the optical properties and band structure calculations for thephotonic crystal structures (PCs) based on one-dimensional (1D) and two-dimensional (2D) ferroelectric
LiNbO3 crystal67. Here we use 1D and 2D periodic crystal structure of dielectric rods and layers in air
background. We have theoretically calculated photonic band structure and optical properties of 1D and
2D LiNbO3 PCs. Beside, we have calculated affect PBG properties of different parameters such as
filling fraction and the shape. In order to get photonic gap map, we have calculated the gaps as afunction of radius of the rods. We have also investigated the nature of guided modes in line defectwaveguide. In our simulation, we employed the finite-difference time domain (FDTD) technique which
implies the solution of Maxwell equations with centered finite-difference expressions for the space andtime derivatives. FDTD schemes are especially promising for the investigation of PBG structures, as
they provide an opportunity of analyzing the spatial distribution of the electromagnetic field in PBG
structure.

67

S. Simsek, Amirullah M. Mamedov, E. Ozbay “Two-Dimensional Ferroelectric Photonic Crystals: Optics and Band
Structure”, Ferroelectrics (in pres: accepted for publ).

ISAF-P1A-25 ___________________________________________________________________________________________________________________

Lattice Dynamics of Alkali Halides in the Anharmonic Regime
M. Kempa1, J. Hlinka1, P. Ondrejkovic1, P. Marton1
1

Department of Dielectrics, Institute of Physics AS CR, Prague, Czech Republic
Email: kempa@fzu.cz

Simple alkali halides, such as NaI or KBr, have been model examples of ionic crystals for decades,
being studied both experimentally and theoretically. Recently, renewed interest in dynamics of alkali
halides appeared: Among others, incorporation of three-body interactions into the polarizable shellmodel has been shown to improve considerably the agreement between lattice dynamic calculations andexperimental results on phonon dispersion68. Furthermore, an intrinsic localized mode (breather) was
discovered in the phonon gap of NaI doped by Tl [2] at high temperatures. Breathers can be regarded as
dynamic nanoclusters, they have been discussed in the context of relaxors3,4, and it would be very
interesting to observe them in simple systems. Such an anharmonic lattice mode could be the same as
the locally excited vibrational mode that causes photoluminescence quenching in alkali halides doped by
ns2 ions5,6, and had been theoretically predicted7, but never experimentally observed before in such asimple structure.
In this contribution, we present our inelastic neutron scattering data on both pure and doped KBr and
NaI, at room and high temperatures, as well as our first-principles calculations based on density
functional theory within the local-density approximation. The position and size of the energy gap in thephonon density of states in a wide range of temperatures from 10 to 700 K are discussed in connection
with a pronounced temperature effect which effectively leads to closure of the phonon gap at hightemperatures8. The results are also discussed in the context of studies of possible intrinsic localized
modes in the phonon gap of alkali halides. We have also attempted to induce the anharmonic latticemodes at low temperatures by UV excitation of the impurity electronic states of Tl+ substitution
centers9.

68

U.C. Srivastava, R.S. Pandey, K.S. Upadayaya, Int. J. Phys. Sci. 5, 972 (2010).
M.E. Manley, A.J. Sievers, J.W. Lynn, S.A. Kiselev, N.I. Agladze, Y. Chen, A. Llobet, A. Alatas, Phys. Rev. B 79, 134304(2009).
3
A. Bussmann-Holder, A. R. Bishop, J. Phys.: Condens. Matter 16, L313 (2004).
4
A. Bussmann-Holder, A. R. Bishop, T. Egami, Europhys. Lett., 71, 249 (2005).
5
J. Hlinka, E. Mihokova, M. Nikl, Physica Status Solidi (b) 166, 503 (1991).
6
E. Mihokova, L.S. Schulman, J. Phys. A: Math. Theor. 43, 183001 (2010).
7
S.A. Kiselev, A.J. Sievers, Phys. Rev. B 55, 5755 (1997).
8
M. Kempa, P. Ondrejkovic, P. Bourges, J. Ollivier, S. Rols, J. Kulda, S. Margueron, J. Hlinka, J. Phys.: Condens. Matter
25, 055403 (2013).
9M. Kempa, P. Ondrejkovic, J. Ollivier, S. Rols, J. Kulda, S. Margueron, M. Fernandez, J. Hlinka, Ferroelectrics 440, 42(2012).
2

ISAF-P1A-26 ___________________________________________________________________________________________________________________

Electrical properties of ferroelectric composites described in terms of local field
inhomogeneity
L. Padurariu1 and L. Mitoseriu1
1Faculty of Physics, Alexandru Ioan Cuza University, 11 Bv. Carol I, 700506 Iasi, Romania

In last years, the material scientists attention was focused in investigation of new dielectricmaterials with tailored properties: permittivity, tunability, P(E), etc. for specific applications.
Unfortunately, the required electrical properties are not usually accomplished in single phase systems,
and the solution was the development of multiphase composite materials. By comparison with a single
phase material, a composite is characterized by the presence of interfaces separating regions withdifferent permittivities, which induce the formation of local inhomogeneous fields which should betaken into account when a theoretical model is proposed.
The aim of this work is the theoretical investigation of the role of the local electric field
inhomogeneity on different electric properties of composites: effective permittivity, nonlinear tunability
and P(E) response. The local field calculations were performed by Finite Element Method (FEM), bysolving the Laplace's equation:   V   0 , where  is the local permittivity, V is the local potential
and the local field is the potential derivative E  V .
Different structures with various microstructure particularities were generated and investigatedby FEM analysis in order to estimate different properties. A remarkable agreement between theexperimental tunability features and the model calculations was obtained in nanostructured BaTiO3
ceramics (composite with di-similar grain bulk and grain boundary regions) with grain size between
5000 to 90 nm and for porous PZT materials (composite with ceramic bulk and air pores) with different
porosity levels [1,2]. Others satisfactory results were derived for a combined FEM-Preisach model
applied to estimate the field-dependence of the polarization (MHL and FORC) in ferroelectriccomposites (particular case: porous PZTN ceramics).
Acknowledgments:
The financial support of the CNCS-UEFISCDI Projects No. PN-II-ID-PCE-2011-3-0745 and
PCCE II-2011-0006 are highly acknowledged.
References:[1] L. Padurariu et al. Phys.Rev.B 85, 224111 (2012)[2] L. Padurariu et al. Appl.Phys.Lett. 100, 252905 (2012)

ISAF-P1A-27 ___________________________________________________________________________________________________________________CALCULATION OF THE DAMPING CONSTANT AND THE ORDER PARAMETERFOR THE LATTICE MODES IN FERROELECTRIC PbTiO3
A. Kiraci and H. Yurtseven*
Department of Physics,
Mıddle East Technical University,
06531, Ankara-Turkey*

Corresponding author: hamit@metu.edu.tr

ABSTRACTThe temperature dependences of the damping constant and the order parameter are calculated forthe lattice modes A1(1TO) and E (1TO) in PbTiO3 using the experimental data by the soft mode- hardmode coupling model and the enrgy fluctuation model. Calculation of the damping constant of bothlattice modes is performed in the temperature range of 400-490 0C close to the ferroelectric-paraelectrictransition (TC=493 0C) in PbTiO3.By relating the frequency to the order parameter (spontaneouspolarization), the temperature dependences of the frequencies for the A1(1TO) and E (1TO) modes in the
ferroelectric phase of PbTiO3 are calculated from the mean field theory.
Our calculated values for the damping constant and the order parameter describe the observed
behaviour of PbTiO3 close to the ferroelectric-paraelectric transition adequately. Our predicted values
for the damping constant of the A1(1TO) lattice mode can be compared with the experimental
bandwidths of this mode when this data is available in the literature.

ISAF-P1A-28 ___________________________________________________________________________________________________________________

Magnetically induced change of polarization due internal
magnetoelectric coupling in PFW-PT ceramics
Bárbara Fraygola1,2, José A. Eiras1
1

Universidade Federal de São Carlos, Departamento de Física, Grupo de Cerâmicas Ferroelétricas, SãoCarlos –SP - Brazil
2
École Polytechnique Fédérale de Lausanne, Material Institute, Ceramic Laboratory LC, Lausanne,
Switzerland.
Email: barbara.fraygola@epfl.ch

2

Polarization (C/cm )Piroelectric Current (nA)

The magnetoelectric (ME) coupling in a material can be either extrinsic (obtained by applying fields) or
intrinsic (characteristic of the material). Multiferroic materials do not necessarily exhibit extrinsic effect.
Their characteristic feature is the presence of, together (or not) with ME effects induced by an external fields,
intrinsic ME effects due to the interaction of strong internal electric and magnetic fields. These spontaneous
effects are manifested at electric and magnetic phase transitions, mediated by an elastic contribution. A
concomitance of magnetism and ferroelectricity then has
0.1
to rely on more subtle microscopic coupling50
PFW-17PT
0.0
mechanisms, driven by spin-orbit coupling in the form
-0.1
40
of Dzyaloshinskii-Moriya interactions or exchangePAFM-0.2
striction, generally obtained in materials with
30
-0.3
complicated structure and low order temperature. For-0.4
example, TbMnO3 and other spin-induced ferroelectrics
20-0.5
exhibit relatively large ME coupling. Another option
PFE
10
-0.6
looking for materials with a large ME coupling goes toTTmixed solid solutions. In this work, a polarization study-0.7
0
was done in Pb(Fe2/3W1/3)(1-x)TixO3 (x=0.15, 0.17,0.20)
-0.8
0
50
100
150
200
250
300
350
400
ceramics looking for the temperature dependence around
Temperature (K)the para-antiferromagnetic transition temperature, inwhich the multiferroic state is established, with a G-type Fig. 18: Pyroelectric current and spontaneous
antiferromagnetic structure. The results where polarization as a function of the temperature forcomplemented with elastics, magnetic and dielectric PFW-17PT ceramic.
proprieties.
N

C

Fig. 1 shows the obtained temperature dependence of the electric polarization for PFW-17PT as an example.
The sample was cooled down to 10 K under an electric field of 0.5 kV/mm and then the current flow fromthe sample was recorded upon heating without the electric field. A series of large decreases of polarization
occurs as the temperature is increased: at 235K, at the ferroelectric phase transition (ΔP FE=26μC/cm2) andaround 143 K (ΔPAFM=24μC/cm2), which is the magnetic transition temperature, showing that an additional
magnetic contribution to the ferroelectric polarization occurred and not only the intrinsic ferroelectric one.
These results can be explained by the governing equations for magnetoelectroelastically coupled materials
and an interpretation of the increase in the electric polarization in the antiferromagnetic phase transition is
proposed on the foundation of general phenomenological basis. The changes in AFM phase transition
observed in PFW-PT are considered to be the result of a renormalization of the FE constants by themagnetoelectric interaction, and are compared with colossal values.

ISAF-P1A-30 ___________________________________________________________________________________________________________________

Magnetoelectric Coupling of Multiferroic Composites under
Combined Thermal-Mechanical-Magnetic loadings
Fang Fei1, Xu Yantao, Zhou Yangyang, Jing Wenqi, Yang Wei
School of Aerospace, Tsinghua University, Beijing 100084
Email: fangf@mail.tsinghua.edu.cn
Extensive scientific and technological interests have been drawn by multiferroic materials since theirversatile combinations of ferroelectricity, ferromagnetism and ferroelasticity. In multiferroic composites,
the ME coupling is a strain mediated product effect achieved via the interfaces between the magnetic
and electrical subsystems through elastic deformation. Due to the strong ME coupling, multiferroic
composites are suitable for applications such as magnetic field sensors, transformers and microwave
resonators. Such applications frequently involve environments where the temperature alters and/or sufferfrom the variation of the mechanical loads.
In this presentation, we will focus on three aspects of our recent developments on ME coupling for
multiferroic composites. Firstly, a multi-peak phenomenon of ME coupling are reported which is very
promising for applications in double-band ME resonators and filters, etc (Fig. 1). An theoretical analysis
was carried out, which agrees well with the experimental observations and enables us to conclude theresonance modes. Secondly, investigations on the temperature or mechanical effects on ME coupling are
carried out. The study aims at exemplifying the temperature or mechanical sensitivity of ME coupling
for the composites, as well as exploring the particular material parameter(s) which plays a dominantrole. Thirdly, an intriguing phenomenon of four-state ME coupling is reported for embedded composites(Fig. 2). A geometric factor k is proposed which captures the size effect on the ME behavior for theembedded composites. Finite element analysis is performed, which fits well with the experimental dataand enables us to deduce the underlying mechanism of the four-state ME coupling.

PP
H

Frequency (kHz)ME (mV/cmOe)H

Hs (Oe)Fig. 1 A 3-D surface chart of ME couplingversus frequency and Hs.

P

H

P

H

Fig. 2 Schematics of the four-statemagnetoelectric coupling.

ISAF-P1A-31 ___________________________________________________________________________________________________________________

Phase transitions of high insulating rhombohedral
xLaxFe1-yTiyO3 multiferroic ceramics

Bi1-

Jian Yu and Linlin Zhang
Functional Materials Research Laboratory, Tongji University, Shanghai 200092, China
Email: jyu@tongji.edu.cn
BiFeO3 is the only known high temperature single-phased multiferroic material, which exhibits
coexistence of ferroelectric and antiferromagnetic ordering below Néel temperature of 370oC. Owing tothermodynamic instability of BiFeO3 compound, it is very difficult to prepare phase pure samples, often
accompanying with impurities of Bi25FeO39 and Bi2Fe4O9. Meanwhile, synthesization of high insulating
BiFeO3 ceramics is a major challenge for material scientists.
In this report, Bi1-xLaxFe1-yTiyO3 multiferroic ceramics with 0.02 ≤ x ≤ 0.12 and 0.01 ≤ y ≤ 0.08 wereprepared with refined electroceramic processing of traditional solid state reaction method. It was foundexperimentally that La/Ti-codoping stabilizes rhombohedral BiFeO3 through forming ternary solid
solution. Then the electrical properties of robust insulating with resistivity of ~1011 m under 90 kV/cm
electric field and low dielectric loss below 0.03 over the frequency range of 20 - 1M Hz were obtained
for all composition studied here. Their robust insulating property was also able to be demonstrated bypoling experiments, for example, the Bi0.98La0.02 Fe0.99Ti0.01O3 ceramics bore more than 5kV DC electricfield at 120oC and then exhibited piezoelectric constant of d33 = 0.6 pC/N. The mechanisms for highinsulating and low dielectric loss were also experimentally investigated and discussed relating to defectand thermodynamic stability of BiFeO3.
For these rhombohedral Bi1-xLaxFe1-yTiyO3 multiferroic ceramics, differential thermal analysis,
temperature-dependent X-ray diffraction and magnetization measurements probe four structural phasetransitions, e.g. TH = 305oC, TN = 365oC, TC = 810oC and TS = 830oC observed in theBi0.98La0.02Fe0.99Ti0.01O3, which are reasonably attributed to antiferromagnetic-helimagnetic,
helimagnetic-paramagnetic, ferroelectric-paraelectric and rhombohedral-cubic lattice structural phasetransition, respectively. With increasing x and y in our experiments, TH and TN changes little but TC and
TS decrease gradually. The change of magnetic phase transition from second-order to first-order andemergence of helimagnetic ordering phase was attributed to Ti 3+ d1 disordered distribution in the -Fe3+
d5-O-Fe3+ d5-O-Fe3+ d5-O- chains.
The rhombohedral Bi1-xLaxFe1-yTiyO3 multiferroic ceramics with robust insulating and low dielectricloss may be able to find possible applications as microwave dielectrics, different from those normal
diamagnetic dielectrics.

ISAF-P1A-32 ___________________________________________________________________________________________________________________

Mixtures of the ferroelectric liquid crystal and magnetic
nanoparticles: New Soft Magnetoelectrics
Brigita Rožič1,2, Marko Jagodič3,4, Sašo Gyergyek1, George Cordoyiannis1,2,5, Mihael Drofenik1, Zvonko
Jagličić3,6, Samo Kralj7, Vassilios Tzitzios8 and Zdravko Kutnjak1,2,9
1
Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
2
Centre of Excellence Namaste, Jamova cesta 39, 1000 Ljubljana, Slovenia
3
Institute of Mathematics, Physics and Mechanics, Jadranska 19, 1000 Ljubljana, Slovenia
4
EN-FIST Centre of Excellence Namaste, Dunajska 156, 1000 Ljubljana, Slovenia
5
Department of Physics, University of Athens, 15784 Athens, Greece
6
Faculty of Civil and Geodetic Engineering, Jamova cesta 2, 1000 Ljubljana
7
Faculty of Natural Science and Mathematics, Koroška cesta 160, 2000 Maribor, Slovenia
8
National Centre for Scientific Research Demokritos, Aghia Paraskevi 15310, Greece
9
Jozef Stefan International Postgraduate School, 1000 Ljubljana, Slovenia
Email: brigita.rozic@ijs.si
Magnetoelectrics have recently attracted significant attention due to their properties and potential forvarious applications69. So far the main focus remains on solid magnetoelectrics, but in our case we
focused on the magnetoelectric effect in a soft material based on mixtures of a ferroelectric liquid crystal(FLC) and magnetic nanoparticles (MNPs).
In this work we report the theoretical estimation and experimental observation of the magnetoelectriceffect in similar systems of two different FLCs, i.e., SCE9 and Felix 015/100, and two different
ferromagnetic NPs, i.e., maghemite and magnetite magnetic NPs70,71,72. NPs were weakly anisotropic
with an average size of 20 nm and coated with an oleic acid to avoid instability of the suspension in thetoluene. The high resolution calorimetry, dielectric spectroscopy and magnetic susceptibility
measurements were performed in the vicinity of the ferroelectric phase transition. Similar disordering
effects on the ferroelectric phase transition were found as in the case of the aerosils73 and the impact of
the MNPs on the dielectric response was observed. Measurements of the impact of the electric field on
the magnetic susceptibility via SQUID-based magnetometer confirmed the indirect coupling between
the NP’s magnetic moments and LC’s electric polarization.
Obtained experimental results are in good agreement with the theoretical predictions and they provide astrong support for the generally expected behavior in such mixtures. This enhances the chance toengineer the soft composite magnetoelectrics.

69

W. Erenstein et al., “Multiferroic and magnetoelectric materials”, Nature, vol. 442, 05023, 2006.

70

B. Rožič et al., “Orientational order-magnetization coupling in mixtures of magnetic nanoparticles and the ferroelectricliquid crystal”, Ferroelectrics, vol. 410, p. 37-41, 2011.

71

B. Rožič et al., “Multiferroic behavior in mixtures of the ferroelectric liquid crystal and magnetic nanoparticles”, Mol.
Cryst. Liq. Cryst., vol. 545, p. 99-104, 2011.

72

B. Rožič et al., “Mixtures of magnetic nanoparticles and ferroelectric liquid crystal: New soft magnetoelectrics”,
Ferroelectrics, vol. 431, p. 150-153, 2012.

73

G. Cordoyiannis et al., “Pretransitional effects near the smectic A-smectic C* phase transition of hydrophilic andhydrophobic aerosil networks dispersed in ferroelectric liquid crystals”, Phys. Rev. E, vol. 75, 021702, 2007.

ISAF-P1A-33 ___________________________________________________________________________________________________________________

Epitaxial (Sr1-xBax)MnO3 thin films: towards strain-induced
ferroelectricity
L. Maurel1,2, J. A. Pardo1,3,*, M. Algueró4, C. Becher5, E. Langenberg1, J. Blasco2,6, C. Magén1,2, P.
Ramos7, R. Jiménez4, J. Ricote4, P. Štrichovanec1, I. Lucas2,6, L. Morellón1,2, M. Fiebig5, M. R. Ibarra1,2,
P. A. Algarabel2,61

INA, University of Zaragoza, Spain. 2Condensed Matter Physics Dept., University of Zaragoza, Spain.
Materials Science Dept., University of Zaragoza, Spain. 4ICMM-CSIC, Cantoblanco, Spain. 5Materials
Dept., ETH, Switzerland. 6ICMA-CSIC, Zaragoza, Spain. 7Dpto. Electrónica, UAH, Alcalá de Henares,
Spain

3

(*) email: jpardo@unizar.es
Recent theoretical predictions and experimental results suggest that paraelectric SrMnO3 with the ABO3
perovskite structure could become ferroelectric upon artificial expansion of the unit cell, either by
epitaxial strain1 or partial substitution of Ba for Sr (ref.2). This would give rise to a new class ofmultiferroic pervoksites where ferroelectricity would be driven by off-centring of the magnetic cation
Mn4+.
Here we have investigated the effect of both Ba doping and epitaxial strain on the structure and electric
properties of SrMnO3 thin films. Pulsed laser deposition with in situ RHEED monitoring was used to
grow strained (Sr1-xBax)MnO3, 0≤x≤0.5 (SBMO) thin films on (001)-oriented perovskite substrates, withstrain ranging from -1% (compressive) to +3% (tensile). X-ray diffraction shows that, under appropriate
deposition conditions, the perovskite pseudocubic phase is stabilized over the hexagonal phase, despite
the latter being favored with increasing Ba content. Optimized films show fully coherent cube-on-cube
epitaxial growth and are chemically homogeneous and defect-free, as determined by scanningtransmission electron microscopy and electron energy loss spectroscopy.
Nonlinear optics measurements reveal that some of our SBMO films emit optical second harmonic
generation signal, pointing to spatial inversion symmetry being broken (necessary condition for
ferroelectricity). Electric measurements and piezoresponse force microscopy were used to investigate
the ferroelectric properties of epitaxially strained SBMO films.

__________________________________
1

J. H. Lee and K. M. Rabe, Phys. Rev. Lett. 104, 207204 (2010)2

H. Sakai et al., Phys. Rev. Lett. 107, 137601 (2011)

ISAF-P1A-34 ___________________________________________________________________________________________________________________The Magnetoelectric Coupling in a Self-Assembled Epitaxial
Nano-composite Driven by Chemical Interaction
Wen-I Liang1, Yuanming Liu2, Wei-Cheng Wang3,Heng-Jui Liu1, Sheng-Chieh Laio4, Hong-Ji Lin3,
Chih-Huang Lai4, Elke Arenholz5, Jaingyu Li2, Ying-Hao Chu1
1
Department of Materials Science and Engineering, National Chiao Tung University, HsinChu, 30010,
Taiwan2
Department of Mechanical Engineering, University of Washington, Seattle, WA 98195, USA
3
National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
4Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013,
Taiwan5
Advanced Light Source, Berkeley, CA 94720, USA
Email: yhc@nctu.edu.tw

Complex oxide heterostructures have triggered a plethora of studies with novel phenomena incondensed matter physics because it provides the possibility to integrate dissimilar oxide with diverse
functionalities. Among them, self-assembled vertical nano-composite, as one approach to build
heterostrucutre, has enlarged the playground of complex oxide heterostructure due to structural, physicaland chemical interactions between dissimilar oxides. From the previous studies, the structural andphysical interactions are demonstrated comprehensively; however, the information of chemicalinteraction, or atomic diffusion, which is more or less inevitable in two-phase system, is still missing so
far. In this study, it is designed the chemical-interaction-induced magnetoelectric coupling effect exhibits
in two antiferromagnetic materials: BiFeO3 and LiMn2O4 vertical nano-composite.
The self-assembled (BiFeO3)x:(LiMn2O4)1-x vertical heterostructure with different composition ratio
were grown by pulse laser deposition. Via the scrutiny of scanning electron microscope, X-ray
diffraction, nano Auger and high resolution transmission electron microscope, a fundamental view
between the inter-diffusion and the composition ratio is visualized. Based on this chemical interaction,
we have found the both ferroelectricity and ferromagnetism coexist in the (BiFeO3)0.75:(LiMn2O4)0.25
nano-heterostructure. Furthermore, in order to understand this behavior, a concrete connection between
chemical diffusion and the induced magnetic moment is proposed when we conduct soft x-ray circulardichroism to investigate the local environment of transition metals. The last part of this study shows thestrong magnetoelectric coupling effect between these two chemical changed phases. Thus, in this study,
we have manipulated successively the chemical interaction between dissimilar oxides heterostructure todemonstrate the new-emerged physical properties and its coupling effect, which would be a key study toextend the practical value in vertical nanoheterostructure.

ISAF-P1A-35 ___________________________________________________________________________________________________________________

Effect of composition on functional properties of ferroelectric-ferrite
composite systems
Cristina Elena Ciomaga1, Mihai Valentin Pop1, Leontin Padurariu1, Mirela Airimioaei2, Carmen Galassi3and Liliana Mitoseriu1
12Faculty of Physics, “Al. I. Cuza” University of Iasi 700506, Romania
Faculty of Chemistry, “Al. I. Cuza” University of Iasi 700506, Romania
3
CNR -ISTEC, Via Granarolo no. 64, I-48018 Faenza, Italy
E-mail: cristina.ciomaga@uaic.ro

The ferroelectric, dielectric and magnetic properties related to the microstructures in the xNiFe2O4-(1x)Pb0.988(Zr0.52Ti0.48)0.976Nb0.024O3 (xNF-(1-x)PZTNb) magneto-electric composites with x= 2, 5, 10, 20,
30, 40, 50, 60, 70 and 100 wt% are investigated. The di-phase ceramics prepared in situ by sol-gel
method present homogeneous microstructures, higher density and a better mixing of the two phases.
The temperature dependence of dielectric properties showed a sharp ferroelectric to paraelectric phasetransition peak at around 360°C for low NF concentrations and a diffuse phase transition at around
330°C for high amounts of ferrite in the composites. Thus, the addition of NF phase induces a
microscopic heterogeneity in composites and a distribution of different localized Curie points. From
frequency dependence of the complex dielectric permittivity it was observed a dispersive behavior, due
to Maxwell-Wagner effect. The higher degree addition of magnetic phase contributes to the interfacial
polarization, causing a significant increase of the real part of permittivity for frequencies below 1 kHz.
The ferroelectric properties reveal that with increasing the NF concentration in the composites it was
obtained flattened P-E loops with smaller values of the remnant polarization. In contrast, the magnetic
properties improve with addition of ferrite phase. However the coercitive field (Hc) for all the composite
samples is larger than that of pure NiFe2O4 phase.
For describing the dependence of the polarization on the applied electric field, a combined model basedon Classical Preisach Model (CPM) and Finite Element Method (FEM) was developed and comparedwith the experimental data.
Acknowledgements: These works were financial supported by CNCSIS-UEFISCSU, projects number
PN II-RU TE code 187/2010 and PN-II-ID-PCE-2011-3-0745.

ISAF-P1A-36 ___________________________________________________________________________________________________________________

Influence of substrate–film interface engineering on themultiferroic BiFeO3

Alim Solmaz1, Mark Huijben1, Beatriz Noheda2, Guus Rijnders1
Mesa+ Institute for Nanotechnology , University of Twente, Enschede, The Netherlands
2
Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
1

Email: a.solmaz@utwente.nl
Multiferroics, such as BiFeO3, which simultaneously exhibit multiple order parameters such as
antiferromagnetism and ferroelectricity, enable the development of novel magnetoelectric devices byutilizing the intrinsic magnetoelectric coupling in which one can control the electric polarization by
applied magnetic fields or the magnetism by applied electric fields. This could lead to new applications
in magnetic data storage, spintronics, and high-frequency magnetic devices, which do not require large
currents and magnetic fields for operation.
In bulk, BiFeO3 is a rhombohedrally distorted perovskite crystal where the ferroelectricity arises due tothe displacement of Bi ions with respect to FeO6 octahedra. This results in an electrical polarization thatlies along the <111>pc directions and, thereby, to formation of three types of domain walls i.e. 71˚, 109˚
and 180˚, each of which show distinctive properties such as conductivity and magnetism. In addition tothat, the antiferromagnetic properties of BiFeO3 are exploited in order to create an exchange bias with aferromagnetic layer such that two coupling effects can be used to manipulate the ferromagnetic state byelectric field74. Additionally, it has been shown that a ferromagnetic state can be induced at the interface
between BiFeO3 and La0.7Sr0.3MnO3 thin films75. Thus it is important to have atomic level control of thegrowth of BiFeO3 thin films in order to obtain specific properties at domain walls and interfaces.
In our work, we focus on the heteroepitaxial growth of BiFeO 3 single crystal thin films on SrTiO3
substrates by pulsed laser deposition. We demonstrate that the initial BiFeO3 growth is very sensitive tothe terminating layer of the substrate. Singly TiO2-terminated substrates can be switched to SrO
termination by interval deposition with the assistance of Reflective High Energy Electron Diffraction(RHEED) technique. BiFeO3 thin films grown on SrO and TiO2 singly-terminated substrates show
different morphologies as well as different ferroelectric domains. This indicates that the sticking of
bismuth oxide species on TiO2-terminated surfaces is different than that of iron oxide on SrO terminatedsurfaces. This determines the interface quality between the BiFeO3 thin film and the substrate. Keeping
in mind that the interfaces become more influential as the film gets thinner, we emphasize theimportance of interface engineering for highly controlled multiferroic devices. We claim that, in BiFeO3
thin film growth, the atomic terminating layer of the substrate should be taken into account as well, next
to other factors that are known to influence the ferroelectric domain formation, such as screening
charges, lattice mismatch or substrate miscut.

74

Chu Y. et al., Electric-field control of local ferromagnetism using a magnetoelectric multiferroic , Nat. Mater., 7, 478(2008).
75

Yu P. et al, Interface Ferromagnetism and Orbital Reconstruction in BiFeO3-LaSrMnO Heterostructures, PRL 105, 27201(2010).

ISAF-P1A-37 ___________________________________________________________________________________________________________________

Optimal Layout Design of Magnetoelectric Laminates: Effects of Mechanical Boundary Conditions
Kyung Ho Sun1, Jae Eun Kim2, Yoon Young Kim3
1

2

Department of System Dynamics, Korea Institute of Machinery & Materials,
Faculty of Mechanical and Automotive Engineering, Catholic University of Daegu,
3
School of Mechanical and Aerospace Engineering, Seoul National University
Email: sunkh@kimm.re.kr

Recently, multiferroic or magneto-electro-elastic composites, made of piezoelectric andmagnetostrictive materials, have received a significant research interest for potential applications in
novel multifunctional devices. These multiferroic composites exhibit an additional functionality: theextrinsic magnetoelectric (ME) effectvia elastic mediation. In suchcomposite materials, the performanceis critically dependent on thecomposition of constituent materials
and their structural configuration. The
authors first proposed the design
method of multiferroic composites by
topology optimization and provided
the understanding of the maximized
ME effects76. In this investigation, apractical layout design approach tofind optimal ME laminates (2-2 type) Fig. 19: The optimized ME laminates with 5 layouts under threemechanical boundary conditions. Note that optimal layout
using the genetic algorithm will besequence is different according to the given mechanical boundarypresented. The multiferroic BaTiO3conditions.
CoFe2O4 composite is analyzed by a
two-dimensional finite element formulation and the magnetoelectric coupling factor by some stored
energy expressions is considered as an objective function to evaluate the magnetoelectric effect. Since
ME effect is the stress-mediated phenomenon, the performance of ME laminates is highly dependent onmechanical boundary conditions. Figure 1 shows the optimized piezoelectric/magnetostrictive phasesequence by the proposed design method. A comparison of results indicates that the ME composites
should have different layouts with each boundary condition. From this study, a design guideline on how
to enhance the ME effects in terms of the applied mechanical boundary conditions can be gained.

76

K. H. Sun and Y. Y. Kim, “Design of magnetoelectric multiferroic heterostructures by topology optimization”, J. Phys. D:
Appl. Phys., vol. 44, 185003, 2011.

ISAF-P1A-38 ___________________________________________________________________________________________________________________

Angular Dispersion of Oblique Phonon Modes in BiFeO 3 frommicro-Raman scattering
J. Hlinka1, J. Pokorný1,2, F. Borodavka1, E. Simon1, I. Gregora1, S. Karimi2, I. M. Reaney2
1

Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
2
Dept. of Materials Science and Engineering, The University of Sheffield, Sheffielk, UK
Email: pokorny@fzu.cz

Bismuth ferrite (BiFeO3) is a prototypical multiferroic system, ferroelectric up to TC ~ 1100 K and
antiferromagnetic up to TN ~ 640 K. It exhibits rhombohedrally distorted perovskite structure with R3csymmetry at room temperature. Characterisation of polar phonon modes is essential for understanding
its dielectric and electromechanical behaviour.
Assigning Raman spectra of BiFeO3 is a complex
task due to mixing of vibrational modes caused bygeneral orientation of naturally grown crystal facets.
The measured oblique phonon modes do not coincidewith any pure TO or LO mode and their frequencies
continuously vary with the orientation of the phonon
propagation vector (angular dispersion). For an
optically uniaxial single crystal, modes can be
assigned by analysing a set of spectra taken fordifferent angles between the phonon propagation
vector and the optical axis. To avoid demanding
experiment on de-twinned single crystal, we collecteda large enough set of micro-Raman spectra obtained
within different randomly oriented grains of bulk
ceramics. The data were curve fitted to a sum of
damped harmonic oscillators and sorted by frequency
evolution of one of the clearly distinct modes. The
angle between the phonon propagation vector and theFig. 20: Angular dispersion of phonon
vector of the spontaneous polarisation (optical axis)xxii
was obtained numericallyusing initial TO and LO modes in BiFeO3. Solid lines represent thecomputed angular dispersion curves, open
frequencies from DFT calculated data. The obtained
circles are the experimental fitted mode
angular dispersion of the phonon mode parameters then frequencies as a function of grain
enabled full mode assignment.
orientation.
This work was supported by EPSRC Grant No.
EP/H048049/1, by Project GACR P204/10/0616 and by AV0Z10100520.

ISAF-P1A-39 ___________________________________________________________________________________________________________________

Structural Phase Transitions in Bi1-xCaxFeO3 Multiferroics
V. A. Khomchenko1, I. O. Troyanchuk2, D. M. Többens3, V. Sikolenko4, J. A. Paixão1
1

2

CEMDRX/Department of Physics, University of Coimbra, Coimbra, Portugal
SSPA “Scientific-Practical Materials Research Centre of NAS of Belarus”, Minsk, Belarus
3
Helmholtz-Zentrum-Berlin for Materials and Energy, Berlin, Germany
4
Laboratory for Neutron Scattering, Paul Scherrer Institute, Villigen, Switzerland
Email: uladzimir@fis.uc.pt

BiFeO3 perovskite remains one of the most popular objects of condensed matter research. Indeed, thecoexistence of spin and electric dipole ordering observed in this material in a broad temperature range
and giving rise to the promissing cross-coupling effects is interesting from the viewpoint of both
fundamental and applied physics. BiFeO3 crystallizes in a rhombohedral R3c structure permitting thepolar ionic displacements along the <111>c direction of the parent cubic perovskite cell. To be suitable
for applications, the polarization should be coupled to the net magnetization, which is, however, lockedin the cycloidal modulation superimposed on the G-type antiferromagnetic (with a weak ferromagnetic
component) structure. One of the ways allowing the modulation to be suppressed is a chemical
substitution.
In present work, the neutron powder diffraction and magnetization measurements of the Bi1-xCaxFeO3(0.05≤x≤0.14) compounds belonging to the intermediate concentration range separating the polar
antiferromagnetic (x~0) and nonpolar antiferromagnetic (x~0.2) phases have been carried out. It has
been shown that Ca substitution induces appearance of weak ferromagnetism in the initial ferroelectricR3c phase, but modifies the picture of polar displacements, so the average PbZrO3-like antiferroelectric
structure (S.G. Pbam) is stabilized at x=0.11. Further increase of the Ca content leads to thetransformation of the antipolar ionic shifts to give rise to the Pbam→Imma transition near x=0.14. A
structural study performed for the x=0.05 compound at high temperature reveals the heating-induced
R3c→Pnma phase transition. Analysis of the compositional dependence of the spontaneous
magnetization and polarization in the R3c phase shows that Ca2+ substitution ensures a balanced
influence on the magnetic and ferroelectric subsystems of BiFeO 3 allowing its multiferroic behavior to
be improved.
This work is supported by funds from FEDER (Programa Operacional Factores de Competitividade
COMPETE) and from FCT-Fundação para a Ciência e a Tecnologia under the project PEstC/FIS/UI0036/2011.

ISAF-P1A-40 ___________________________________________________________________________________________________________________

DIELECTRIC AND IMPEDANCE SPECTROSCOPY OF Fe DOPED
0.94(Na0.5Bi0.5TiO3)-0.06BaTiO3 CERAMICS

Kęstutis Bučinskas1, Maksim Ivanov1, Robertas Grigalaitis1, Jūras Banys1, Eva Sapper2, Jürgen Rödel2
1

2

Faculty of Physics, Vilnius University, Lithuania
Institute of Materials Science, Technische Universität Darmstadt, Germany
Email: maksim.ivanov@ff.vu.lt

Ever since the discovery of piezoelectric effect, piezoelectric materials have been rapidly developed andwidely used. The most widely used piezoelectric materials are Pb(Zr,Ti)O3(PZT)-based ceramics
because of their superior piezoelectric properties. However due to legislative enforcements,
representatively the European RoHS/WEEE regulations77, lead-free piezoelectric materials have been
extensively studied last decade. Among the10
studiedmaterials,(1-x)(Na0.5Bi0.5TiO3)500K
10441K
xBaTiO3 ceramic family has been of
10
403K
360K
particular interest because of the similar
10
piezoelectric properties to PZT ceramics78.
10
3
2
1
0



' (S m 

-1
-2

10

In the present work the dielectric and
10
impedance
properties
of
Fe
doped
10
0.94(Na0.5Bi0.5TiO3)-0.06BaTiO3 ceramics in
10
20Hz-1GHz frequency range and 300-500K
10temperature range are investigated. The
10
10 10 10 10 10 10 10 10 10 10 10 10
measurements of dielectric permittivity weref (Hz)
performed during freezing cycle with 1K/min
Fig. 21: Frequency dependency of real part of complex
temperature variation rate. Conductivity was conductivity of Fe doped 0.94(Na0.5Bi0.5TiO3)-0.06BaTiO3
calculated using dielectric permittivity data. ceramics
Fig. 1 shows frequency dependency of the realpart of complex conductivity. Experimental
data was fitted with generalized universal Jonscher’s law79. The best fits were obtained for 403K-500K
temperature range. One conductivity process was distinguished with Arrhenius behavior of σ DC andpossible cause of conductivity process is discussed.
-3
-4
-5
-6
-7

-1

0

1

2

3

4

5

6

7

8

9

10

77

EU-Directive 2002/95/EC: Restriction of the use of certain hazardous substances in electrical and electronic equipment(RoHS). Official Journal of the European Union 46 (L37) pp. 19-23,2003.
78
Thomas R. Shrout, Shujun J. Zhang, “Lead-free piezoelectric ceramics: Alternatives to PZT?” J. Electroceram. 19, pp 111124, 2007.
79

I. I. Popov, R. R. Nigmatullin, A. A. Khamzin, and I. V. Lounev, “Conductivity in disordered structures: Verification of
the generalized Jonscher's law on experimental data”, J. Appl. Phys. 112, 094107, 2012.

ISAF-P1A-41 ___________________________________________________________________________________________________________________

Proton Diffusion
as an Origin of Dielectric Properties of Water and Ice
Alexander Volkov1, Vasily Artemov1, Artem Pronin1,2
A. M. Prokhorov Institute of General Physics, RAS, 119991 Moscow, Russia
2
Dresden High Magnetic Field Laboratory, HZ Dresden-Rossendorf, 01314 Dresden, Germany
1

Email: aavol@bk.ru
Despite of ubiquity of water and ice and a very long history of investigations of their physical properties,
the microscopic origins of the electrodynamic properties of these substances are still in focus of sharp
scientific debates [1]. It is generally accepted that both, water and ice, are dielectrics with unexpectedly
high proton dc conductivity and high static permittivity, the origin of which is not fully understood. The
orientational motion of the dipole moments of H2O molecules is traditionally related to the static
permittivity, while the dc conductivity is explained by the ability of a Н2О molecule to self-dissociate.
To a large extent, these two directions of research (orientation → permittivity, ionization →conductivity) are being developed independently and hardy overlap. The first of them deals not onlywith water, but also with other substances, particularly with hydrogen-bonded ferroelectrics, such as
KDP [2]. The second direction is closely related to the chemical acid-base index, the pH [3].
Recently, from our analysis of broad-band panoramas of dielectric response (Fig. 1), we have found an
approach, which offers a uniform explanation for both, the permittivity and the conductivity spectra [4].
The new approach reveals the Debye relaxation and the dc conductivity to be two manifestations of asingle microscopic mechanism – the diffusion of protons, generated via self-ionization of H2O
molecules. In Ref. [4], we developed aphenomenological model of Brownian-like
diffusion and showed that the static permittivity ofwater results from flickering of separated charges
with a fast recombination rate, while the dc
conductivity is due to diffusion with a much slower
recombination rate. These long-living charges are
eventually responsible for pH = 7.
In this presentation, we apply our model to the caseof solid ice and compare the obtained parameters
for ice and water. We show that the dielectric
spectra of ice can be scaled up to the liquid-water
spectra (Fig. 1), using a single parameter, theactivation energy for diffusion. The ice lattice isappeared to be inherently filled with a giant amount Fig. 22: Dielectric response of water and ice at
0 °C in terms of the dielectric function (top) andof ionic defects.
the dynamical conductivity (bottom).
1

A. von Hippel, “The Dielectric Relaxation Spectra of Water,
Ice, and Aqueous Solutions,and their Interpretation”, IEEE Transactions on Electrical Insulation, vol. 23, p. 801-816, 1988.
2
R. Blinc, B. Žekš, “Soft modes in ferroelectrics and antiferroelectrics“, p. 317, North-Holland, Amsterdam, 1974
3
D. Marx, “Proton Transfer 200 Years after von Grotthuss: Insights from Ab Initio Simulations“, ChemPhysChem,
Vol. 7, p. 1855-1870, 2006.
4
A. A. Volkov, V. G. Artemov, A. V. Pronin, “Proton Electrodynamics in Liquid Water“, arXiv:1302.5048, 2013.

ISAF-P1A-42 ___________________________________________________________________________________________________________________

Study of the ferroelectric phase transition in GeTe
using time-domain THz spectroscopy
C. Kadlec, F. Kadlec, P. Kužel and J. Petzelt
Institute of Physics, Academy of Sciences, Prague, Czech Republic
Email: kadlecch@fzu.cz
Germanium telluride (GeTe) is a narrow-gap semiconductor with conducting properties important forpotential applications. It belongs to so-called phase change materials: its crystalline form exhibits anelectrical conductivity orders of magnitude higher than the amorphous one. The unit cell of crystalline
GeTe includes two atoms only, thus it is the simplest known ferroelectric (FE). Upon heating, it
becomes paraelectric (PE) at Tc≈350°C. However, a controversy persists about the character of its FE
phase transition (PT). While Raman spectra showed phonon softening in the FE phase and suggested adisplacive character of the PT, there is no such evidence above Tc. Recent XANES data80 showed no
anomaly of the Ge-Te bond length at Tc, which indicates an order-disorder behavior. The question about
the PT character is of fundamental interest.
The free charge carriers prevent the use of traditional
spectroscopic techniques on bulk crystals. We present
results of high-temperature measurements of GeTethin ﬁlms by means of time-domain terahertz
spectroscopy. We were able to detect the IR active
excitations; both FE and PE phases were studied. The
PT manifests itself in a change of slope in the THz
conductivity σTHz(T). Above Tc, we detected an
excitation located in the sub-THz range. This mode isabsent in the FE phase and unambiguously present in
the PE phase (see Fig. 1).
The complex permittivity spectra ε(ω) were determined numerically from the complex transmittance. We
set up a model of ε(ω) with the high-frequency limit
ε∞, one harmonic oscillator, one Drude term due to Fig.1:
free THz spectra of real permittivity ofGeTein the PE phase; symbols:
carriers and, in the PE phase, one relaxator:
experimental data, lines: fits. Inset:
2
2
p
 0
 r rconductivity at 0.4 THz with a minimum PE      2
 2

2
0    i   i r  i at the PT.
where ω0 , ωp and ωr are the oscillator, free carrier plasma and relaxation frequencies, respectively, Γand γ denote the oscillator and plasma damping and ∆ε, ∆εr are the contributions to ε(ω) due to theoscillator and relaxator, respectively. The relaxator parameters in the PE phase are compatible with theCurie-Weiss law: ∆εr = C/(T − Tc) with C ≈ 105 K.
To summarize, we performed the ﬁrst time-domain THz spectroscopy study of the FE PT in GeTe thinﬁlms. In the PE phase, we observed a relaxation typical for an order-disorder behavior. Moreover, only alimited softening of the lowest-lying phonon occurs. Therefore, our experimental data indicate themixed (displacive and order-disorder) nature of the PT81.

80

P. Fons et al., 'Phase transition in crystalline GeTe: Pitfalls of averaging effects', Phys. Rev. B 82, 155209, 2010
F. Kadlec et al., 'Study of the FE PT in GeTe using THz spectroscopy', Phys. Rev. B 84, 205209, 201181

ISAF-P1A-43 ___________________________________________________________________________________________________________________

Thermal evolution of crystal structure of Bi1-xPrxFeO3 ceramics acrossrhombohedral-orthorhombic phase boundary
D.V. Karpinsky, A.L. Kholkin
CICECO/Department of Materials and Ceramics Engineering, University of Aveiro, 3810-193 Aveiro,
Portugal
Email: karpinski@ua.pt
Enhanced ferroic properties expected in BiFeO3-based multiferroics near the morphotropic phaseboundaries still attract continuous interest, while an origin of such improvement is still ambiguous [1, 2].
Assuming a close correlation between the enhanced ferroic properties and specific structural phases wefocused our study on thermally driven phase transition of Bi1-xPrxFeO3 compounds with chemicalcomposition within the phase boundary region.
Room temperature XRD patterns of Bi1-xPrxFeO3 ceramics prove the following sequence of thephase transitions with increasing x: rhombohedral polar (R) – orthorhombic antipolar (O2) –orthorhombic nonpolar (O1) [3]. The crystal structure of the selected compound Bi0.875Pr0.125FeO3 ischaracterized by a coexistence of the rhombohedral (R) and the orthorhombic (O2) phases. An analysisof the variable temperature diffraction data testifies a decrease of the antipolar orthorhombic phasefraction with temperature growth. The antipolar phase remains at temperatures above 350°C, whereas at
400°C a strong evidence of new nonpolar orthorhombic phase has been revealed, thereby at thetemperatures about 400°C all three phases coexist.
The structural phase transition
occurring in the vicinity of the triple point isof particular interest as its mechanism candecipher a driving force of the polar nonpolar phase transformations. Taking into
account available structural data for REdoped BiFeO3 solid solutions [4] and theevolution of crystal structure estimated forBi0.875Pr0.125FeO3 compound we consider thedominant role of the chemical bondpeculiarities
associatedwithorbitalhybridization along with the size effect inthe structural phase transitions in BiFeO3
based materials.
Fig.1: Structural phase diagram of Bi0.875Pr0.125FeO3 compoundshowing phase coexistence regions along with the evolution of theunit cell volume.

4.

1.
Y. H. Chu, Q. Zhan, C.-H. Yang et al., Appl.
Phys. Lett. 92 (2008) 102909.
2.
G. L. Yuan, S. W. Or, J. M. Liu, Z. G. Liu,Appl. Phys. Lett. 89 (2006) 052905.
3.
D.V. Karpinsky, I.O. Troyanchuk, O.S.

Mantytskaya et al., Solid State Commun. 151 (2011) 1686.
I.O. Troyanchuk, D.V. Karpinsky, M.V. Bushinsky et al., J. Am. Ceram. Soc. 94 (2011) 4502.

ISAF-P1A-44 ___________________________________________________________________________________________________________________High temperature single-phased magnetic ferroelectrics: BiFeO3Bi(Zn1/2Ti1/2)O3-PbTiO3 ceramics
Linlin Zhang, Xianbo Hou, Jian Yu*
Functional Materials Research Laboratory, Tongji University, Shanghai, China
Email: 0zhanglinlin0621@tongji.edu.cn *jyu@tongji.edu.cn
Multiferroic materials have been attracting an increasingly fundamental and practical interest. Owing to
the lacking of high-temperature single-phased ferromagnetic-ferroelectric multiferroics with strong
linear magnetoelectric coupling effect, these materials have not been widely applied yet. Meanwhile,
synthesization of pure single-phased and high insulating material is a major challenge for materialscientists. Here, perovskite-structured BiFeO3-Bi(Zn1/2Ti1/2)O3-PbTiO3 solid solutions, fabricated withconventional electroceramic processing and sintered at temperature around 890oC, were systematicallyinvestigated. The authors reported on the dielectric, ferroelectric and magnetic properties of the ternary
solid solutions. It was found that high insulating and low dielectric loss ceramics are obtained for the (12x)BiFeO3-xBi(Zn1/2Ti1/2)O3-xPbTiO3 ceramics (0.05 ≤ x ≤ 0.25). Pure rhombohedral phase of
0.7BiFeO3-0.14Bi(Zn1/2Ti1/2)O3-0.16PbTiO3 was obtained, with the dielectric loss below 0.04@1kHz,
which bore 4kV DC electric field at 100oC and exhibited piezoelectric constant of d33 = 0.5 pC/N. Twoferroic phase transition temperatures of TN ~ 330 oC and TC ~ 810 oC were detected from DSC and DTA
measurements, respectively. The magnetic and electrical properties were also studied under different
heat treatments. Our researching is to design high temperature high performanced perovskite-structured
magnetic-ferroelectric multiferroic compounds.

ISAF-P1A-45 ___________________________________________________________________________________________________________________

Does the lithium niobate Z cut surface reconstruct?
Rebecca Hölscher, Simone Sanna, Wolf Gero Schmidt
Computational Materials Science Group, University of Paderborn, Germany
Email: reh@mail.upb.de
LiNbO3 (LN) is a frequently used material for optical and acoustic applications due to its strong
piezoelectric, pyroelectric, and photorefractive properties. As for other ferroelectric materials, thesurface reactivity can be manipulated by polarization reversal. This opens the possibility for therealization of devices like molecular detectors82.
Unfortunately, there are only few data about the microscopic structure of the surface available. Whilemost existing studies83, do not find surface periodicities other than the 1x1 bulk-truncated structure,
there are very recent indications that at elevated temperatures large surface reconstructions might occur
for both the positive and the negative Z cut84.
Here surface phase diagrams calculated from first principles are presented. Thereby a large number ofstructures of different morphology andstoichiometry are investigated by means ofdensity functional theory within thegeneralized gradient approximation (DFTGGA). In contrast to earlier work85, thepossibility of large surface reconstructions istaken into account. Interestingly, we find thatfor certain preparation conditions indeed large
surface reconstructions may be stable. Their
formation is rationalized in terms of surface
electrostatic interactions.

Fig. 23: Top view of one of the possible reconstructions
on the LiNbO3 (0001) surface, lithium atoms are shownin grey (light and dark), niobium atoms in white andoxygen atoms in red, the surface unit cell is outlined indark grey.

82

D. Li, M. H. Zhao, J. Garra, et al., “Direct in situ determination of the polarization dependence of physisorption on
ferroelectric surfaces”, Nature Materials, vol. 7, p. 473-477, 2008.
83
S. Rode, R. Hölscher, S. Sanna, et. al., “Atomic-resolution imaging of the polar (0001) surface of LiNbO3 in aqueous
solution by frequency modulation atomic force microscopy“, Physical Review B, vol. 86, p. 075468, 2012.
84

85

A. Kühnle, S. Klassen, S. Rode, Private communication

S. Sanna, W. G. Schmidt, “Lithium niobate X-cut, Y-cut, and Z-cut surfaces from ab initio theory”, Physical Review B, vol.
81, p. 214116, 2010.

ISAF-P1A-46 ___________________________________________________________________________________________________________________

Behavior of Polar Nanoregions in Lead Free Relaxor
Ferroelectrics
Chandra Shekhar Pandey1, Juergen Schreuer1, Manfred Burianek2, Manfred Muehlberg2
1

Institute of Geology, Mineralogy, & Geophysics, Cristallography, Ruhr University Bochum, Bochum,
Germany2
Institute of Crystallography, University of Cologne, Cologne, Germany
Email: chandrashekhar.pandey@rub.de

An understanding on how the polar nanoregions (PNRs) affect on the properties of materials is a subjectof great curiosity, challenge and one of the key parameters of interest to the materials scientist as well ascondensed matter physicist. PNRs observed in relaxor ferroelectrics (hereafter relaxors) are an exampleof this type of challenge.
Behavior of polar nanoregion and hence relaxor behavior of lead free relaxor ferroelectrics will be
explained incorporating elastic properties, and Czochralski grown Ca0.28Ba0.72Nb2O6 (CBN-28) as an
example. CBN-28 belongs to the partially filled tetragonal tungsten bronze (TTB) family. The unit cellof the TTB-structure contains two voids of type A1 and A2, and four small voids of type C.
Consequently, the general formula for niobateswith TTB-structure is (A1)2(A2)4C4Nb10O30.
Recently, we have reported the relaxor behaviorof CBN-28 with the evidence of the existence of
the Burns temperature TB, and the intermediatecharacteristic temperature T*.86 In the present
work, we show that the dynamics of polar
nanoregions (and hence the relaxor behavior)
strongly varies with the variation ofcomposition87 (see Fig. 1), and doping88.
Evidence is found for a more pronounced
relaxor behavior with increasing A1 site content.
Curie temperature (TC) and the Burns
temperature are also very sensitive to thecomposition, whereas the T* appears unaffectedwith composition variation and doping.
Presented results open the perspective tounderstand the relaxor behavior of many lead Fig. 24: Temperature evolution of the cij (in relative
free relaxors with composition variation, and scale) for CBN-x in its paraelectric phase.
doping above TC.
86

Pandey et. al., Anomalous elastic behavior of relaxor ferroelectric Ca 0.28Ba0.72Nb2O6 single crystals, Phys. Rev. B 84,
174102, 2011.
87

Pandey et. al., Relaxor behavior of CaxBa1-xNb2O6 tuned by Ca/Ba ratio and investigated by resonant ultrasoundspectroscopy, Phys. Rev. B (Accepted for publication, in press), 2013.
88

Pandey et. al., Anomalous elastic behavior of relaxor ferroelectric Ca 0.28Ba0.72Nb2O6:Ce studied by resonant ultrasoundspectroscopy, Appl. Phys. Lett. 99, 252901, 2011.

ISAF-P1A-47 ___________________________________________________________________________________________________________________

Ferroelectric and dielectric properties of solid solutions in thesystem xBi0.5K0.5TiO3 – (100-x)Bi0.5Na0.5ZrO3
Espen Tjønneland Wefring, Maxim I. Morozov, Mari-Ann Einarsrud, Tor Grande
Department of Materials Science and Engineering,
Norwegian University of Science and Technology, Trondheim, Norway
Email: tor.grande@ntnu.no
Development of lead-free piezoelectric ceramics has attained significant attention in recent years as
there are environmental concerns related to the lead containing Pb(Zr1-xTix)O3 commonly used today.89
One prominent class of lead-free alternatives is mixed bismuth-alkali titanates such as Bi0.5K0.5TiO3 andBi0.5Na0.5TiO3, both in their pure state and as a solid solution. Substitution of Zr for Ti in these materials
has not been studied widely earlier. Here we report on synthesis and characterization of thexBi0.5K0.5TiO3 – (100-x)Bi0.5Na0.5ZrO3 (BKT-BNZ) materials system.
Conventional solid state synthesis was used to fabricate dense and phase pure ceramics. Structuralcharacterization was done using x-ray diffraction both at room temperature (RT, Fig. 1) and elevatedtemperatures (RT - 600°C). A transition from tetragonal BKT to pseudo cubic xBKT was identified forx ≤ 90. Dielectric properties were studied with respect to both temperature (RT - 600°C) and frequency(10a Hz, a = {6, …, 0}) and the electric field induced strain response of the materials was investigated at
RT. All materials studied show relaxor-like behaviour with a frequency dispersion of the dielectric
constant, and the maximum dielectric constant was observed for 85BKT (Fig. 2). The maximum strain
response of the composition joint was seen for 90BKT. Both compositions of maximum performanceare close to where the phase transition from tetragonal to pseudo cubic crystal structure was observed.

Fig. 25: X-ray diffractograms of compositions Fig. 2: Temperature dependence of the dielectric
100BKT-50BKT
constant for 100BKT – 50BKT at 1 kHz

89

J. Rödel, W. Jo, et al. "Perspective on the Development of Lead-free Piezoceramics.", J. Am. Ceram. Soc., vol. 92(6), p.
1153-1177, 2009.

ISAF-P1A-48 ___________________________________________________________________________________________________________________

Influence of Plasma-Source Ion Irradiation on Formation of
Domain Structure in MgO:LiNbO3 Single Crystals
Shur Vladimir, Pryakhina Victoria, Alikin Denis, Negashev Stanislav, Besedina Nadezhda
Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University,
Ekaterinburg, Russia
Email: victoria.pryahina@labfer.usu.ru
We have studied the formation of the domain structure with charged domain walls (CDW) underapplication of the inhomogeneous electric field in MgO doped LiNbO3 single crystals after plasmasource ion irradiation.
The investigated samples represented 1-mm-thick plates of single-crystalline LiNbO3 doped by 5%
MgO (MgO:LN) cut normal to the polar axis. The irradiation of Z+ polar surface was done by Ar+ ionswith energy ranged from 2 to 5 keV (flux 0.5 μA/cm2, fluence (1-6)∙1017 cm-2, time 5 min, vacuum 10-4Torr). The maximal temperature caused by radiation heating ranged from 400 to 600OC. The sample was
fixed on the metal substrate by silver paste to prevent modification of the opposite polar surface.
It was shown that plasma-source ion irradiation of MgO:LN drastically increases the bulk conductivity
due to out-diffusion of oxygen in vacuum90. The spatially inhomogeneous sample conductivity leads todependence of the switching field in the bulk on the depth. The field distribution in the bulk and its timedependence has been extracted from the recorded interferometry pattern on the YZ side of the sample.
The variation of the irradiation energy and duration allows to change the field value and distribution.
Kinetics of the domain structure during polarization reversal under application of triangular andrectangular field pulses has been studied by recording of instantaneous domain images. The switching
field was applied using liquid electrolyte (saturated LiCl water solution). The formation and growth of
domains with CDW91 have been observed. Interaction between approaching domain walls leads toformation of the dense net of residual domains.
The position and the shape of the stable CDW have been studied by confocal Raman spectroscopy anddomain visualization on YZ cross-sections. The correlation between domain structure and field
distribution has been revealed.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has beenused. The research was made possible in part by RFBR (Grants 13-02-01391-а,
12-02-31377, 11-02-91066-CNRS-а), by Ministry of Education and Science (Сontracts 14.513.12.0006,
16.740.11.0585).

90

V.I. Pryakhina, V.Ya. Shur, D.O. Alikin, S.A. Negashev, “Polarization reversal in MgO:LiNbO 3 single crystals modified
by plasma-source ion irradiation”, Ferroelectrics, vol. 439, p. 20-32, 2012.
91

V.Ya. Shur, E.L. Rumyantsev, E.V. Nikolaeva, E.I. Shishkin, “Formation and evolution of charged domain walls incongruent lithium niobate”, Appl. Phys. Lett., vol. 77, p. 3636-3638, 2000.

ISAF-P1A-49 ___________________________________________________________________________________________________________________

Interface Control of Surface Photochemical Reactivity in Ultrathin
Epitaxial Ferroelectric Films
Jason Chen1,5*, Haidong Lu2, Heng-Jui Liu3, Ying-Hao Chu3, Steve Dunn4, Kostya (Ken) Ostrikov5,6,Alexei Gruverman2, and Nagarajan Valanoor1
1School of Materials Science and Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
2Department of Physics and Astronomy University of Nebraska Lincoln,
Lincoln, NE 68588, United States
3Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
4School of Engineering and Materials, Queen Mary University of London, Mile End Road, E1 4NS, London
5CSIRO Materials Science and Engineering, P. O. Box 218, Lindfield, New South Wales 2070, Australia
6School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia

Email: jason.chen1@student.unsw.edu.au
Asymmetricalelectricalboundary
conditions
in(001)-oriented
Pb(Zr0.2TiO0.8)O3 (PZT) epitaxial ultrathin
ferroelectric films are exploited to control
surface photochemical reactivity determinedby the sign of the surface polarization
charge. The preferential orientation ofpolarization in the as-grown PZT layer canbe manipulated by choosing an appropriate
type of the bottom electrode material.
Photochemical activity of the PZT surfaces
with different surface polarization charges
has been tested by studying deposition ofsilver nanoparticles from AgNO3 solution Figure 1. PFM (a, d), SEM (b, e) and EDX (c, f) data acquired
under UV irradiation. We found that PZT in PZT/SRO/STO (a-c) and PZT/LSCO/STO (d-f). The PFM
surfaces with preferential C+ orientation images demonstrate that the bottom electrode controls the asgrown polarization orientation. The SEM images obtained
possess a more active surface for metal after UV irradiation show the appearance of particulates with
reduction than their C counterparts, the particle density being visibly higher on PZT/SRO/STO.
evidenced by large differences in the EDX scans confirm the presence of Ag on both samples afterconcentrationofdepositedsilver UV irradiation with the intensity of the Ag signal being more
nanoparticles. This effect is attributed to prominent in PZT/SRO/STO.
band bending at the bottom interface which
varies depending on the difference in work functions of PZT and electrode materials. A full descriptionof the band profile will be presented to explain the observed effects.
This work is supported by Australian Research Council (ARC), Australian Nanotechnology Network (ANN),EPSRC, National Science Foundation - Materials Research Science and Engineering Center (NSF grant DMR080521). J.C. thanks CSIRO for OCE Ph.D. top-up scholarship support.

* jason.chen1@student.unsw.edu.au

ISAF-P1A-50 ___________________________________________________________________________________________________________________

Multiscale modeling of multiferroic nanocomposites
Prokhorenko Sergei, Igor Kornev
Laboratoire Structure, Propriétés et Modélisation des Solides, Ecole Centrale Paris
Email: sergei.prokhorenko@ecp.fr
Multiferroic and magnetoelectric crystals form a very specific class of materials with possibly wide
range of applications in novel electronic devices, such as next-generation biomagnetic sensors,
actuators, energy storage and tunable microwave devices. Owing to coexistence of several orderparameters of different nature and various coupling mechanisms between them, modeling of multiferroic
compounds becomes one of the main challenges in the field of material-design.
Leaving aside the problem of pure single-phase multiferroics, our study focuses on nanocomposites
comprising multiferroic and ferroelectric compounds with perovskite structure. Taking as a base an
existing ab initio effective Hamiltonian model92, we develop a new methodological extension targeting
better consideration of local and global symmetry of the supercell structure. As a consequence, shortrange intersite dynamical matrix obtains a bigger set of independent coefficients93 and thus encodes the
local morphology of the material, while dipole-dipole interaction symmetry captures the global
structure, e.g. connectivity of the composite.
The developed computational scheme is then applied to BiFeO3 based nanocomposites. It is shown thatby varying geometrical characteristics of the structure such as connectivity of inclusion components,
surface area of the hetero-interface or fractality of the host matrix, one can drastically change energybalance between short-range and long-range interactions allowing for transition temperature tuning,
control of the symmetry of the ordered phases, and change of coupling between different orderparameters. For instance, BiFeO3-BaTiO3 nanocomposites with different connectivities and nanoscalemorphology show rich crossover behavior patterns (Fig.1).
The obtained results show that the developed methodology captures main features of nanocomposites
systems, opening a new path to optimization and design of multiferroic materials. This work is
supported by ERA.Net RUS, STProject-133, Nano-C grant.
Fig.1 (BiFeO3)0.5(BaTiO3)0.5; Magnetoelectriceffectdependency
ongeometry
during“Checkerboard”- “Disordered mixture” crossover.
This figure shows dependence of normalized
polarization on applied external magnetic field forstructures with different texture. While incheckerboard structure (curve 1) the coupling
between polarization and magnetic field is purely
defined by interaction of electric dipoles at theinterface, the disordered mixture (curve 4) exhibits
behavior close to BiFeO3 nanoclusters embedded
in polarizable matrix.

92

Zhong, D. Vanderbilt, K. Rabe Phys. Rev. Lett. 73, 1861 (1994); Phys. Rev. B 52, 6301 (1995)

93

A. A. Maradudin, S. H. Vosko Rev. Mod. Phys. 40, 1 (1968)

PFM Poster
Forum Hall
Monday, July 22 2013, 01:00 pm - 04:30 pm

PFM-PA-1______________________________________________________________________________________________________________________

Piezo- and ferroelectricity of cellular polypropylene electrets films
characterized by piezoresponse force microscopy
Faxin Li1, Chenhong Miao1, Yao Sun1, Yongping Wan2
1

State Key Lab for Turbulence and Complex Systems, College of Engineering, Peking University,
Beijing, 100871, China
2
School of Aeronautics and Astronautics, Tongji University, Shanghai, 200050, China
Email: lifaxin@pku.edu.cn

Cellular electrets polymer is a new ferroelectret material exhibiting large piezoelectricity and has
attracted considerable attentions in research and industries. Property characterization is very important
for this material and current investigations are mostly on macroscopic properties. In this work, we
conduct nanoscale piezoelectric and ferroelectric characterizations of cellular polypropylene (PP) films
using piezoresponse force microscopy (PFM). First, both the single-frequency (or conventional) PFM
and the dual frequency resonance-tracking PFM testing were conducted to map the converse
piezoelectric constant d33 of the cellular PP film, which is only 13-18pC/N for the former and 7-11C/N
for the latter, strongly dependent of the vibration amplitude (or pressing force). Then, using theswitching spectroscopy PFM (SS-PFM), we studied ferroelectricity of the cellular PP films. Results
show that it exhibits the typical ferroelectric-like phase hysteresis loops and butterfly-shaped amplitude
loops, which is similar to that of a poly(vinylidene fluoride) (PVDF) ferroelectric polymer film (SeeFig.1). However, both the phase and amplitude loops of the PP film are intensively asymmetric, which isthought caused by the nonzero remnant polarization after poling. Finally, the D-E hystersis loops of boththe cellular PP film and PVDF film were measured by a ferroelectric analyzer, using the same wave
form as that in the SS-PFM, and show significant differences. In conclusion, we suggest that theferroelectric-like behavior of cellular electrets polymers can well be distinguished from that of typicalferroelectrics, both macroscopically and microscopically.

(a)

(b)

Fig.1 Phase hysteresis loops and amplitude butterfly loops of (a) cellular PP films and (b) PVDF films
characterized by switching spectroscopy PFM

PFM-PA-2______________________________________________________________________________________________________________________

Nanoscale switching behavior of BiFeO3 film investigated by PFM
and CAFM
W. Luo1,2, H. Zeng1, Y. Shuai1,2, C. Wu1, W. Zhang1, S. Zhou2, S.Gemming2, N. Du3, H. Schmidt3
1

State Key Lab. of Electronic Thin Films and Integrated Devices, UESTC, Chengdu, China
2
Institute of Ion Beam Physics and Materials Research, HZDR, Dresden, Germany.
3
Department of Materials for Nanoelectronics, Technical University Chemnitz, Germany

Email: luowb@uestc.edu.cn
In this contribution, BiFeO3 (BFO) polycrystalline thinfilms have been grown on Pt/Ti/SiO2/Si and BFO
epitaxial film were deposited on SrRuO3 coated
SrTiO3 substrates by pulsed laser deposition.
Nonvolatile94, bipolar, and multilevel2 resistive
switching has been observed in polycrystalline thinfilms as shown in fig.1 (a). In contrast, the I-V loopsof Au/BFO/SRO structure, shown as fig.2 (a),exhibited different RS behavior like a switchable
diode. Piezoelectric force microscopy (PFM) andcurrent atomic force microscopy (CAFM) using Pt Fig. 26: multilevel resistive switching I-V plots (a),coated tips were combined to study the obscure surface morphology (b), ferroelectric domain
connection between RS and ferroelectric polarization structure (c), and local current image drawn in a log
in both polycrystalline and epitaxial BFO film. A scale (d) of BFO polycrystalline films deposited on
ferroelectric-related resistive switching behavior has Pt/Ti/SiO2/Si substrate, respectively.
been observed in both the BFO/Pt and BFO/SRO
structures. As it can be seen from figure 1, theconductive paths nucleated at almost the same
position as the nucleation site of ferroelectric domain.
As shown in fig.2 (c), the BFO epitaxial film show
well defined surface step structure, which caneliminate the interfere factors on PFM and CAFM
measurements from surface roughness. The BFO
films were electrically switched with a set of positive
and negative voltages. For these regions, local current
were measured by the CAFM with a voltage of -2V.
Fig. 2: Switchable diode I-V curves (a) surface
The CAFM images revealed that the conducting state morphology (b), ferroelectric domain structure (c),of the green area shown in fig.2 (d) was modulated and local current image drawn in a log scale (d) ofby about two orders of magnitude after the BFO films deposited on SrRuO coated SrTiO
3
3
polarization direction was switched upwards shown substrate. respectively.
as yellow area in fig.2 (c). These results demonstrated
that the RS of BFO is close related to ferroelectric polarization and the barrier height of the top and bottom
contact.

1

Y. Shuai. S. Zhou, C. Wu, W. Zhang, D. Bürger, S. Slesazeck, T. Mikolajick, M. Helm, and H. Schmidt, Control ofrectifying and resistive switching behavior in BiFeO3 thin films, Appl. Phys. Express 4, p. 095802, 2011.
2

Y. Shuai, X. Ou, W. Luo, N. Du, C. Wu, W. Zhang, D. Burger, C. Mayr, R. Schuffny, S. Zhou, M. Helm, and H. Schmidt,
Nonvolatile multilevel resistive switching in Ar+ irradiated BiFeO3 thin films, IEEE Elec. Dev. Lett., vol. 34, p. 54-56, 2013.

PFM-PA-3______________________________________________________________________________________________________________________

Force microscopy study of Magnetoelectric coupling inperovskite FM/FE thin films heterostructures
P. Mirzadeh Vaghefi1, C. A. P. Alves1, F. Figueiras1, A.C. Lourenço1, V. S. Amaral1
1

Department of Physics & CICECO, University of Aveiro, 3810-193 Aveiro,
Email: pegah.mirzadeh@ua.pt

The coupling of magnetic, strain and dielectric degrees of freedom and the potential multifunctionalities
revived the interest on multiferroics oxides95,96,97. Understanding dynamic coupling between orderparameters on the local scale is a major problem in Condensed Matter Physics and will also be the key tofuture device applications of Strongly Correlated Electron (SCE) oxide materials. These applications offerroelectric materials for electronic devices require the quantitative study of local switching behaviour.
In this work La1-xBaxMnO3 (33nm)/BaTiO3 (34nm)/La1-xBaxMnO3 (33nm) trilayer films were growncoherently on Si (100) and Al2O3 (001) oriented substrates by
9.09
UHV RF-magnetron sputtering. X-ray diffraction was used toanalyse film growth orientation and texture. Considering thatthe polarization can exist at a nanoscale volume, we used thepiezo-force and magnetic force scanning probe microscopies(PFM/MFM)
for
studying
local
electricalandelectromechanical properties of the manganite overlayer and to
0.00
study the modification of trilayers with application of localbias. Local poling is also used to modify nearby magnetic areas
via mechanical stress and field effects at voltages, -/+30, -/+20
and -/+10 V, as shown in figure 1. Local piezoelectric
hysteresis measurements detect electric field-induced
deformation at a nanoscale. We observe a clear modification of
the piezo-response of trilayer surface encompassing local
piezoelectric hysteresis measurements which detect electricfield-induced deformation on the nanoscale and contrast
change in magnetic areas via mechanical stress and field
effects, which make them interesting issues to continue workon them. Also, no deformation of topography was observed at /+10 V.
The work was partially supported by FCT projects
PTDC/FIS/105416/2008,
PTDC/CTM/099415/2008_
FCOMP-01-0124-FEDER-009368
and
PEstC/CTM/LA0011/2011

Figure 1: (a) PFM image of the area afterpoling of -30, 30, -20, 20, -10 and 10V fromleft to right, on trilayer film deposited onoriented Al2O3 substrate, (b) hysteresis loop of
trilayer on Al2O3 substrate.

95

W. Eerenstein, N. D. Mathur and J. F. Scott, , Nature, 442, 7104, 759-765, 2006.

96

S. W. Cheong and M. Mostovoy, , Nature Materials, 6, 1, 13-20, 2007.

97

R. Ramesh and N. A. Spaldin, , Nature Materials, 6, 1, 21-29, 2007.

PFM-PA-4______________________________________________________________________________________________________________________

SPM study of localized magnetoelectric effect in
BaTiO3/Hexaferrite composite ceramics
Harsh Trivedi1, Vladimir V. Shvartsman1, Doru C. Lupascu1, Robert C. Pullar2,3, Andrei Kholkin2,3
1

Institute for Materials Science, University of Duisburg-Essen, Essen, Germany
2
CICECO, University of Aveiro, Aveiro, Portugal
3
Department of Materials and Ceramic Engineering, University of Aveiro, Aveiro, Portugal
Email: harsh.trivedi@uni-due.deComposite multiferroics are the materials with Piezoelectric and magnetostrictive constituent phases,
with an indirect stress mediated coupling at the interface resulting in a bulk magnetoelectric effect. As
compared to the single phase multiferroics the coupling in composites is usually large and exists at room
temperature, however due to general conducting nature of the magnetic phase in composites, bulk
measurements of ferroelectric properties is difficult. In this study, composite ceramics with ahomogeneous distribution of piezoelectric (BaTiO3) and magnetostrictive hexaferrite (BaFe12O19/
SrFe12O19) phases were investigated locally using Scanning Probe Microscopy (SPM) techniques like
MFM (Magnetic Force Microscopy) and PFM (Piezoresponse Force Microscopy). The domain patternsof each constituent phase (Viz. Magnetic and Ferroelectric) were observed under applied conjugate(Electric/Magnetic) fields and correlated with the virgin state of the domains. Apparent direct andindirect coupling effects were observed in the form of restructuring of magnetic domain and changes inthe switching properties of ferroelectric domains. In the end an analysis for magnetic domain wallmotion is presented considering the Bloch-wall case.

PFM-PA-5______________________________________________________________________________________________________________________

Modulating domain wall conduction in epitaxial Pb(Zr0.2Ti0.8)O3
thin films by varying oxygen vacancy densities
Gaponenko Iaroslav1, Karthik Jambunathan2, Martin Lane W.2, Paruch Patrycja1
1

MaNEP-DPMC, University of Geneva, Geneva, Switzerland, CH-1205
2
DMRL, University of Illinois, Urbana, IL, USA 61801
Email: iaroslav.gaponenko@unige.ch

Electrical conduction at domain walls in otherwise insulating ferroelectric or multiferroic materials has
been variously explained as intrinsic – with local structural changes decreasing the band gap [1],extrinsic – where defects preferentially accumulating at domain walls allow a conduction pathway
across the sample [2], or as a dynamical phenomenon related to (ir)reversible microscopic displacementsof the domain walls in an applied electric field [3]. In particular in BiFeO 3, recent studies havehighlighted the importance of oxygen vacancies for the observed conduction, both at domain walls [4]and at more complex closure/vortex structures [5].
Here, we report on the significant role of oxygen vacancies in the domain wall conduction we
have previously demonstrated at 180° domain walls in epitaxial Pb(Zr0.2Ti0.8)O3 thin films [6]. For thesestudies, we compare the conduction behavior of two different types of epitaxial PZT thin films grown on
SrRuO3 electrodes: the first grown by off-axis RF magnetron sputtering on SrTiO3 (STO), the secondgrown by pulsed laser deposition (PLD) on DyScO3 (DSO). Both types of samples present a smoothsurface with a slightly granular morphology and a RMS roughness of 0.3 nm, but the Czochralski-grown
DSO substrates show higher crystalline quality and less dislocations than Verneuil-grown STO, andpresent much lower densities of oxygen vacancies.
Using piezoresponse force microscopy (PFM) and conductive atomic force microscopy(c-AFM)
we show that contrary to the case of sputtered films, which show domain wall conduction as-grown, no
domain-wall-specific current is observed in the PLD grown films at low-medium voltages. At highvoltages, displacement currents related to the nucleation and growth of new domains are observed
throughout the whole sample, not specifically at the domain wall, together with static hot-spots oflocalized current possibly related to pin-hole defects. However, after high-vacuum annealing of the
PLD-grown films at 300 °C for 30 minutes, domain wall conduction is recovered, and shows
qualitatively similar behavior to that observed in the sputtered films.
These results suggest that a threshold density of oxygen vacancies – naturally occuring in thecase of sputtered films, or engineered artificially for the PLD films – is needed for conduction at thedomain walls.
[1]

J. Seidel et al, Nature Mater. 8, 229-234 (2009)
J. Seidel et al, Phys. Rev. Lett. 105, 197603 (2010)[3]
P. Maksymovych et al, Nano Lett. 11, 1906 (2011)[4]
S. Farokhipoor et al, J. Appl. Phys. 112, 052003 (2012)[5]
N. Balke et al, Nature Physics 8, 81-88 (2012)[6]
J. Guyonnet et al, Adv. Mater. 23, 5377 (2011)[2]

PFM-PA-6______________________________________________________________________________________________________________________

Piezoresponse force microscopy study of doped (K,Na)NbO 3based ceramics for piezoactuator applications
Danka Gobeljic1, Vladimir Shvartsman1, Ke Want2, Wook Jo3, Jing-Feng Li2, Jürgen Rödel3, Doru C.
Lupascu1
12Institute for Materials Science, Universität Duisburg-Essen, Essen, Germany
State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing, P.R. China
3
Institute of Materials Science, Technische Universität Darmstadt, Darmstadt, Germany
Email: danka.gobeljic@uni-due.de

A current development of potential lead-free alternatives to Pb(Zr,Ti)O3 (PZT) suggests (K,Na)NbO3(KNN)-based materials as one of the most promising, lead-free piezoceramics. Owing to its excellent
electromechanical properties, particular dopants-modified KNN is suitable for high-precision,
temperature-stable actuator applications. Material, besides high piezoelectric constant d33, exhibits highfield-induced strain of significant stability in a range from room temperature up to 175 °C98.
Here, we demonstrate results of a Piezoresponse Force Microscopy (PFM) study on
0.95(Na0.49K0.49Li0.02)(Nb0.8Ta0.2)O3-0.05CaZrO3 ceramics. Investigation of the temperature dependent
domain evolution, indicating a sequence of phase transformation responsible for enhanced piezoelectric
properties, is revealed. Correspondingly, locally obtained longitudinal piezoelectric coefficient shows
comparable temperature behavior as macroscopic small piezoelectric coefficient, d33.
Demonstrated study provides nanoscopic insight on mechanisms of enhanced electromechanicalproperties in the studied KNN-based ceramics, establishing correlation with macroscopically determinedmaterial properties.

98

K. Wang, F. Yao, W. Jo, D. Gobeljic, V. V. Shvartsman, D. C. Lupascu, J.F. Li and J. Rödel, “Temperature-Insensitive(K,Na)NbO3-based Lead-free Piezo Actuator Ceramics”, Accepted by Adv. Funct. Mat. 2013.

PFM-PA-7______________________________________________________________________________________________________________________PFM images of non-ferroelectric thin films
Borowiak Alexis1, Vilquin Bertrand2, Baboux Nicolas1, Brice Gautier1
1

Institut des Nanotechnologies de Lyon, INSA de Lyon, 20, avenue Albert Einstein, 69621 Villeurbanne, France
2
Institut des Nanotechnologies de Lyon, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully
cedex, France

Email: alexis.borowiak@insa-lyon.fr
Piezoresponse Force Microscopy (PFM) is a powerful tool for the characterization of ferroelectricmaterials thanks to its ability to map and control in a non destructive way domain structures inferroelectric films99.
Most of the time, the ferroelectric behaviour of a film is tested by writing domains of opposite
polarisation with the Atomic Force Microscope (AFM) tip and/or by performing hysteresis loops with
the AFM tip as a top electrode. A given sample is declared ferroelectric when domains of opposite
direction have been detected, corresponding to zones of distinct contrast on the PFM image, or when an
open hysteresis loop is obtained. More prudently in certain cases, the ferroelectricity is at last attested
only when the contrast is stable within several hours100.
But as the thickness of the films studied by PFM decrease, data become difficult to interpret. In
particular, charges trapped after current injection due to leakage currents may contribute in a nonnegligible way to the final contrast of PFM images. As a result a convincing PFM contrast has been
recently observed in non-ferroelectric oxides such as SrTiO3101, (LaxSr1-x)MnO3102 and CaCu3Ti4O12103.
This in not disturbing when the sample under consideration is known to be paraelectric but it may
become a real problem when very thin layers of a well-known ferroelectric material are under study.
It this communication, we will show that the standard procedure used in order to show theferroelectricity of a film can be applied to a non-ferroelectric sample with apparently the same results.
To do so, we use a LaAlO3 amorphous dielectric film and apply similar voltages as for artificiallywritten ferroelectric domains. The resulting pattern is imaged by PFM and exhibit zones of distinct PFM
contrasts, stable with time, similar to the one obtained with ferroelectric samples.
We will explain these results, try and choose the experimental parameters which minimize these effects,
and compare with results obtained on BaTiO3 thin films prepared by Molecular Beam Epitaxy which aresupposed to be ferroelectric. The aim of this study is to establish a reliable procedure which would
remove any ambiguity in the characterization of the ferroelectric nature of such samples.

99

A. Gruverman, O. Auciello, H. Tokumoto, “Scanning force microscopy for the study of domain structure in
ferroelectric thin films”, J. Vac. Sci. Technol. B., vol. 14 (2), p. 602-605, 1996.
100

V. Garcia, S. Fusil, K. Bouzehouane, S. Enouz-Vedrenne, N. D. Mathur, A. Barthélèmy, M. Bibes, “Giant tunnel
electroresistance for non-destructive readout of ferroelectric states”, Nature, vol. 460, p. 81-84, 2009.
101

A. Kholkin, I. Bdikin, T. Ostapchuk, J. Petzelt, “Room temperature surface piezoelectricity in SrTiO 3 ceramics via
piezoresponse force microscopy”, Appl. Phys. Lett., vol. 93, 222905, 2008.
102

R. F. Mamin, I. K. Bdikin, A. L. Kholkin, “Locally induced charged states in La 0.89Sr0.11MnO3 single crystals”,
Appl. Phys. Lett., vol. 94, 222901, 2009.
103

R. Tararam, I.K. Bdikin, N. Panwar, J. A. Varela, P. R. Bueno, A. L. Kholkin, “Nanoscale electromechanicalproperties of CaCu3Ti4O12 ceramics”, J. Appl. Phys., vol. 110, 052019, 2011.

PFM-PA-8______________________________________________________________________________________________________________________Morphological and Ferroelectric Studies of LiNbO3 Films Preparedby a Sputtering Deposition
D.A. Kiselev, R.N. Zhukov, A.S. Bykov, M.D. Malinkovich, Yu.N. Parkhomenko
Department of the Material Science of Semiconductors and Dielectrics
National University of Science and Technology "MISiS"
Leninskiy pr. 4, 119049 Moscow, Russian Federation
Email: dm.kiselev@misis.ru
Lithium niobate (LiNbO3) has been one of the promising ferroelectric materials for potential
applications in the area of modulators, switches, actuators, surface acoustic wave devices, sensors, andwave guides because of its high piezoelectric, photorefractive, and nonlinear optical properties.
However, thin films are advantageous over their bulk counterparts for various device applications. Froma technological point of view, the prospect of LiNbO3 thin films on Si substrates is particularly attractivein view to combine the ferro- and piezoelectric processing capabilities of with lithium niobate theobvious advantages of Si. Indeed, Si technology continues to dominate the microelectronics market,
providing a rigid substrate ideal for lithographic techniques. This will make possible the development ofintegrated devices in which sources, detectors and electronics, as well as ferroelectric and waveguiding
components may be produced on the same wafer.
The studied LiNbO3 films were deposited by radio-frequencies magnetrom sputtering of the singlecrystalline target in Ar/O=1 atmosphere (0.6 Pa) on n-type Si (100) and Si (111) substrates ( = 2 Ω·cm)
with SiO2 buffer layer (thickness ~ 5 nm). The subsequent thermal annealing of the obtained structures
has been done in air at 700 ºС. Atomic force microscopy measurements indicate that the surface
roughness of the LiNbO3 thin films was 4-10 nm, which meets the demands for practical waveguiding
devices. The ferroelectric properties have been studied by visualization of the as-growth domain
structure (vertical and lateral component polarization), recording induced ferroelectric states and thehysteresis loops by piezoresponse force microscopy (PFM) using Scanning probe laboratory NTEGRAPrima (NT MDT, Russia). Also, Kelvin probe force microscopy (KPFM) was used extensively for
determining electric properties in these heterostructures.
The research was financially supported by the Ministry of Education and Science of the RussianFederation out using the equipment of Common-Use Scientific Center “Material Science andMetallurgy” at NUST “MISiS” and by the Program for Creation and Development of the National
University of Science and Technology “MISiS”.

PFM-PA-9______________________________________________________________________________________________________________________

Local stress enhancement of ferroelectricity in GFO thin films
1

Maksym Iazykov, 2Alexandre Thomasson, 1Brice Gautier, 2Natalie Viart
1

2

Institut des Nanotechnologies de Lyon, Villeurbanne/FranceInstitut de Physique et Chimie des Matériaux de Strasbourg, Strasbourg/France
Email: maksym.iazykov@insa-lyon.fr

Today multiferroics become more and more attractive materials because of their fundamental ability to
combine ferroelectric and magnetic properties1. In recent years, multiferroics have been intensively
investigated. However, most of the reported materials demonstrate coupling of the magnetic andferroelectric order parameters at the temperatures much lower or higher than room temperature2,3.
The promising candidate for potential application is Ga2−xFexO3 (GFO) oxides which show
ferromagnetic, ferroelectric and ferroelastic properties at near-ambient temperatures4,5. Thisphenomenon gives them great potential in technological application6,7. However, physical properties of
GFO oxides have been proved for single-crystal samples whereas the device integration requires usingof thin films of these materials which were rarely reported until now8-10.
In this work we performed local probe electrical characterization of GFO thin films. Conductive AFM
measurements showed strong leakage currents when sufficiently high voltages were applied to thesample. This fact makes impossible domain switching by Piezoresponse Force Microscopy (PFM). The
direct mechanical domain writing has not provided switching of polarization. Despite this, we showedthat possible ferroelectricity of GFO can be studied using the Atomic Force Microscope (AFM) as
instrument for local stress enhancement of ferroelectricity. Such method allowed us relatively easy
writing of the ferroelectric domains avoiding the problem of the leakage currents. We hope that thisapproach will lead to better understanding of current and capacitance measurements at the microscopic
level that is critical for possible improvement of the magnetoelectric properties of GFO.
1

N.A. Hill, J. Phys. Chem. B 104, 6694, 2000

2

A.M. dos Santos, S.Parashar, A.R.Raju et al, Solid State Comm. 122(1-2) 49-52, 2002

3

N.Hur, S.Park , P.A.Sharma, J.S.Ahn, S.Guha and S.W.Cheong, Nature. 429 392–5, 2004

4

J.P.Remeika, J. Appl. Phys. 31 263S, 1960

5

G.T.Rado, Phys. Rev. Lett. 13 335, 1964

6

J.H. Jung, M. Matsubara, T. Arima, J.P. He, Y. Kaneko, Y. Tokura, Phys.Rev. Lett. 93, 037 403, 2004

7

A.M. Kalashnikova, R.V. Pisarev, L.N. Bezmaternykh, V.L. Temerov, A. Kirilyuk, T. Rasing, JETP Lett. 81, 452, 2005

8

D. C. Kundaliya, S. B. Ogale, S. Dhar, et al., J. Magn. Magn. Mater. 299 307-311, 2006

9

Z. H. Sun, Y. L. Zhou, S. Y. Dai, et al., Appl. Phys. A: Mater. Sci. Process. 91 97-100, 200810

M. Trassin, N. Viart, G. Versini, et al., Journal of Materials Chemistry 19 8876-8880, 2009

PFM-PA-10 _____________________________________________________________________________________________________________________

Buffer layer effect on microstructures and properties of Pb(Zr,Ti)O3CoFe2O4 layered thin films

Hongcai He, Feifei Luo, Neng Qian, Ning Wang
State Key Laboratory of Electronic Thin Films and Integrated Devices and School of Microelectronics
and Solid-State Electronics, University of Electronic Science and Technology of China, Chengdu
610054, P. R. China

Abstract:
The conductive oxide LaNiO3 thin film was selected as a buffer layer and a bottom electrode for thePb(Zr,Ti)O3-CoFe2O4 composite films derived from the sol–gel method in our previous work. This
LaNiO3 buffer obviously enhanced the magnetoelectric response of the Pb(Zr,Ti)O3–CoFe2O4 bi-layered
thin films. Deeper work will be introduced in this work. The LaNiO3 thin films with different thickness,
surface morphology, preferred orientation and conductivity are deposited on Si substrate as buffer layers
to deposite Pb(Zr,Ti)O3-CoFe2O4 composite films. XRD, SEM / EDS and AFM were used tocharacterize films microstructure. Magnetic force microscopy (MFM) and piezo-force response
microscopy (PFM) were used to characterize the composite film at the local scale. Ferroelectric
hysteresis loops and ferromagnetic hysteresis loops were macroscopically measured. The direct ME
measurement was done in terms of the variation in the induced voltage by the applied magnetic fieldusing a self-made equipment. The results are compared and discussed in relation to the microstructure
and properties of LaNiO3 buffer layers.
Acknowledgement: This work has been supported by Natural Science Foundation of China (51002020,
51272035).

PFM-PA-11 _____________________________________________________________________________________________________________________PFM study of size effects on lead-free ceramics and films of(Bi0.5Na0.5)1-xBaxTiO3 with compositions around the morphotropic
phase boundary
Norberto Salazar1, Dulce Pérez-Mezcua2, M. Lourdes Calzada2, Adriana Gil1, Jesús Ricote2
12

Nanotec Electrónica S.L., Tres Cantos, Madrid, Spain
Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid, Spain
Email: norberto.salazar@nanotec.es

The increasing interest in the development of lead-free piezoelectric materials has drawn the attention tosolid solutions such as 1-x(Bi0.5Na0.5)TiO3-xBaTiO3 (BNBT). Enhanced dielectric, ferroelectric andpiezoelectric properties have been observed for bulk ceramics with compositions close to themorphotropic phase boundary (MPB) between rhombohedral and tetragonal phases104. The preparationof these materials in thin film form is indispensable for their integration into microelectronic devices.
However a drastic decrease in the remnant polarization of BNBT thin films respect to their bulk
counterparts is reported105. This has been attributed to size effects, as the reduction of dimensions in thinfilms leads to smaller grains, which determines the nature of the ferroelectric domain configuration106.
In order to understand the mechanisms that lead to the size effects responsible for the reduction of theremnant properties, ceramics and films of BNBT with different grain sizes are analyzed by
Piezoresponse Force Microscopy. Materials are prepared from sol-gel derived solutions107. The
comparison between the results obtained in micro- and nanometric grain size materials allows us todiscuss the effects of the grain size on the ferroelectric domain configuration, and to relate it to theproperties. Besides, the measurement of local piezoelectric loops and the study of the mobility of thedomain walls under an electric field will shed light onto the role of the grain boundaries. All
measurements were carried out with a Nanotec® scanning force microscope.

104

T. Takenaka, K.I. Maruyama, K. Sakata, “(Bi1/2Na1/2)TiO3-BaTiO3 System for Lead-Free Piezoelectric Ceramics”, Jap. J.
Appl. Phys., vol 30, p. 2236-2239, 1991.
105

I. Bretos, D. Alonso-San José, R. Jiménez, J. Ricote, M.L. Calzada, “Evidence of morphotropic phase boundary
displacement in lead-free (Bi0.5Na0.5)1−xBaxTiO3 polycrystalline thin films”, Mater. Lett., vol 65, p. 2714-2716, 2011.
106
M. Algueró, J. Ricote, R. Jiménez, P. Ramos, J. Carreaud, J.M. Kiat, B. Dkhil, J. Holc, M. Kosec, “Size effect inmorphotropic phase boundary PbMg1/3Nb2/3O3–PbTiO3”, Appl. Phys. Lett., vol. 91, p. 112905, 2007.
107

D. Alonso-San José, R. Jiménez, I. Bretos, M.L. Calzada, “Lead-free ferroelectric (Na1/2Bi1/2)TiO3–BaTiO3 thin films inthe morphotropic phase boundary composition: solution processing and properties”, J. Amer. Ceram. Soc., vol. 92, p. 22182225, 2009.

PFM-PA-12 _____________________________________________________________________________________________________________________

Quantification of Electromechanical Coupling Measured with
Piezoresponse Force Microscopy
Serban Lepadatu1, Markys Cain11

National Physical Laboratory, Hampton Road, Middlesex, TW11 0LW
Email: serban.lepadatu@npl.co.uk

In this work we propose a measurement procedure for calibrating against various artifacts affecting PFM
measurements using a standard procedure and sample. Further inter-laboratory comparisons should
reveal any systematic differences in PFM measurements, working towards a commonly accepted PFM
standard.
Piezoresponse force microscopy (PFM) is an invaluable tool for measuring the piezoresponse offunctional materials at the nanoscale, allowing for high resolution measurements of theelectromechanical coupling of thin films. In this work we address the challenges facing quantification of
PFM by developing standards both through in-house work and inter-laboratory comparisons.
PZT 20-80 epitaxial thin films have been grown to
100 nm thickness on 10×10 mm2 1 at% Nb-doped
SrTiO3 substrates and poled along the c-axis whichlies perpendicular to the substrate plane. Opticallithography was used to define a series of top
electrodes with varying dimensions, capacitancevalues, proximity and thickness. By varying the top
electrode structure various effects are quantified andcalibrated, including substrate bending, electrodeclamping, electric field non-uniformity, tip-surface
contact resistance and PFM tip displacement. Laser
Doppler vibrometry (LDV) measurements of circular
capacitor structures have shown uniform displacement
amplitude, linearly dependent on driving voltage
amplitude. For 10 µm diameter top electrode typicallyd33 = 41 ± 1 pm/V. Good agreement of LDV and PFM
measurements was obtained where the tip
displacement is measured for driving voltage applied
directly to the electrodes, resulting in d33 = 39 ± 3
pm/V, as shown in Figure 1.

Fig. 27: PFM measurements of capacitor structurewith PFM tip placement shown in the inset.
Variation of vertical displacement amplitude withdriving amplitude at 30 kHz is shown with solid
circles for voltage applied directly to the capacitor
structure (●) and open circles for voltage applied
through the PFM tip (○). Linear fitting of data
points gives the d33 value as 39 ± 3 pm/V.

Calibrating for the tip-surface contact resistance and modelling of the tip-surface interaction allows formeasurements of d33 values when driving the voltage through the PFM tip both on the capacitor
structures and on the PZT thin film in scanning mode.

PFM-PA-13 _____________________________________________________________________________________________________________________

Nanoscale piezoresponse and thermal behavior of
ferroelectric domain in multiferroic BiFeO3 thin film
Huarong Zeng, Senxing Hui,Kunyu Zhao, Guorong Li, Qingrui Yin
Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese
Academy of Sciences, Shanghai 200050, China
Email: huarongzeng@mail.sic.ac.cn
Multiferroic materials exhibit simultaneous ferroelectric and magnetic orders, which enable the couplinginteraction between ferroelectric and magnetic orders. This coupling interaction produces various
possibilities in the realization of mutual control and detection of electrical polarization and magnetism.
Recent advances of multiferroelectrics have offered an imperative need to develop high resolution toolfor in-situ investigating ferroelectric/ferromagnetic domain configurations and local physical properties.
Here we introduce piezoresponse force microscopy (PFM) and 3-scanning thermal microscopy (3SThM) to characterize local piezoresponse and thermal behavior of nanoscale domains in multiferroic
BiFeO3 (BFO) thin film. The 3-SThM, developed based on the customer-developed PFM, provides a
powerful tool for imaging locally thermal distributions and characterizing local thermal conductivity.
Ultrahigh resolution PFM imaging reveals that ferroelectric domain wall width is around 2.18 nm for
multiferroic BiFeO3 thin film, which is well consistent with the upper limit values of 2 nm via firstprinciple study [1]. Good polarization retention behavior was also demonstrated in the BFO thin film by
the PFM tip fields. Local thermal conductivity of ferroelectric domains of BFO thin film was firstly
performed by 3-SThM, and was found to be 1.525 W/mK. The local thermal conductivity dependenceof the domain switching behavior was also investigated and discussed in the present study.

PFM-PA-14 _____________________________________________________________________________________________________________________The kinetics of the domain structure of TGS crystals investigated nearphase transition temperature by means of AFM
O.M.Golitsyna, V.O.Chulakova, S.N.Drozhdin
Voronezh State University / Voronezh / Russia
Email: golitsynaom@yandex.ru

Formation of the domain structure of triglycine sulfate crystals (TGS) after their rapid coolingfrom the paraelectric to the ferroelectric phase is essentially non-equilibrium process, which has beenstudied in detail 1,2 in the temperature range of stability of the spontaneous polarization PS, i.e. far fromthe phase transition temperature TC. It is of interest to study this process in the vicinity of the phasetransition, where the fluctuations of PS can significantly affect the kinetics of forming and evolution of
the domain structure. The analysis of the literature shows that to date, such experimental studies havenot been carried out at temperatures close to TC. In this paper the evolution of the domain structure ofboth nominally pure TGS and TGS doped with L,α-alanine was investigated at temperatures near TC.
The visualization of the domain structure of the polar cuts of these crystals was carried out by meansof atomic force microscopy (AFM) in contact mode of piezoelectric response (microscope Solver P47
Pro, cantilevers NSG 11/TiN). The samples were transferred into the paraelectric phase and after 30
minutes of exposure at ≈ 333 K cooled at a rate of 10 K / min to the desired temperature. The accuracyof temperature stabilizing was equal to ± 0,05 K. At a given temperature T ≤ TC –1.0 K the evolutionof freshly formed domain structure was observed.
The kinetics of the formation of the domain structure was studied by means of calculations of thespace-time correlation function C (r, t) = <S(r,t)S(0,t)>, where S (r, t) = +1 or –1, depending on the signof the domain at the point with coordinate r. The following parameters of the domain structure also
were calculated:
1) average characteristic correlation length L, defined as the distance at which the correlation function
takes the value of C (r = L (t), t) = 1/2 with respect to its original value at r = 0, 2) the total perimeter ofthe domain walls, 3) areas of the domains of opposite sign, and the coefficient of static unipolarity.
It was found that near TC the forming of a stable domain configuration occurs with a significantly
different kinetic parameters comparing with those calculated in 1,2. It was found that the formation of
the domain structure in nominally pure and doped TGS is described by different kinetic parameters. The
general tendency of investigated processes of domain structure evolution is their slowing down withthe distance from the Curie temperature.

_____________________
1
2

H.Orihara, N.Tomita, Y. Ishibashi. Ferroelectrics, vol.95, p.45-48, 1989.
V. Likodimos, M. Labardi, M. Allegrini. Physical Review B66, p.024104-1-02410407, 2002.

PFM-PA-15 _____________________________________________________________________________________________________________________

Piezo Force Microscopy as a Fundamental Tool for
Characterization of Nanoporous PbTiO3 Thin Films
Alichandra Castro,1 Paula Ferreira,1 Brian Rodriguez2, Paula M. Vilarinho1
1

Department of Materials and Ceramic Engineering, University of Aveiro, Aveiro, Portugal
Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin,
Ireland
2

Email: alichandra@ua.pt
Nowadays, due to the increasing demand on portable electronic devices with ultrahigh density data storageand lower power consumption, the miniaturization of the ferroelectric has become an important issue. This
progressive development requires the morphology control of materials and the understanding the effects ofsize reduction on properties at the nanoscale, namely the ferroelectric properties. Within this context, wehave been exploiting nano and mesoporosity in ferroelectric materials, because ordered meso and nanoporous thin film arrays may be used as ferroelectric platforms for the conception of new multifunctional
materials, such as multiferroics. Multiferroics materials are currently of great interest for applications in
microelectronics. However, preparing nanoporous oxide thin films is not a trivial task and the influence ofporosity on the piezo and ferroelectric properties of these ferroelectric matrices is practically unknown. Dueto exceptional spatial resolution, Scanning Probe Microscopy (SPM) techniques and in particular
Piezoresponse Force Microscopy has become an important high resolution characterization tool for
visualization of domain structures in ferroelectric thin films at the nanoscale.
Thus, in this work, Vertical Piezoresponse Force Microscopy (VPFM), Lateral Piezoresponse ForceMicroscopy (LPFM), and Switching Spectroscopy Piezoresponse Force Microscopy (SSPFM) are used tocharacterize the piezoelectric and ferroelectric properties of mesostructured PbTiO3 thin films prepared bysol-gel and evaporation-induced self-assembly methodologies.108 The porous PbTiO3 thin films were
thermally treated at different temperatures in order to assess the effect of the microstructure crystallization
evolution on the ferroelectric properties and the results obtained for nanoporous thin films are compared with
PbTiO3 dense thin films prepared under the same conditions. Scanning electron microscopy (SEM) and PFM
results clearly demonstrate the existence of two distinct areas, which exhibit different crystallinity andconsequently different local piezoelectric properties. The area with strong out-of-plane piezoresponse
increases with the thermal treatment temperature, as well as the tetragonal phase. In addition, at a more local
scale it is also observed that the regions near the pores exhibit a higher piezoresponse that is possibly
associated with a higher degree of crystallinity in these regions. The ferroelectric behaviour in these samples
was also demonstrated by the typical square-shaped piezoelectric hysteresis loops. Some of these hysteresis
loops exhibit imprint and the relation between this vertical and lateral shift is related to the processing
conditions and porosity. We evaluated also the piezoelectric and switching properties in different grainsusing PFM and SS-PFM. The size influence of each grains on electric properties was discussed as a functionof coercive bias, imprint voltage and saturation response. Microstructural details were analyzed by ScanningElectron Microscopy (SEM), Transmission Electron Microscopy and Ultra-Raman. X-ray diffraction (XRD)
analyses were used to characterize the phase content, lattice parameters and mesoporosity.
Acknowledgements
The authors thank FCT and FEDER (QREN – COMPETE) for funding the project PTDC/CTM/098130/2008
and to the FCT for the Doctoral fellowship SFRH/BD/67121/2009. We thank also to the COST Action
MP0904 SIMUFER for funding the STSM in Dublin.
108

P. Ferreira, R. Z. Hou, A. Wu, M.-G. Willinger, P. M. Vilarinho, J. Mosa, C. Laberty-Robert, C. Boissière, D. Grosso, C.
Sanchez, “Nanoporous Piezo- and Ferroelectric Thin Films”, Langmuir, vol. 28, p. 2944-2949, 2012.

PFM-PA-16 _____________________________________________________________________________________________________________________

Local Polarization Reversal
in the Vicinity of 180o Domain Wall in Lithium Niobate
Ievlev Anton1, Shur Vladimir1, Neradovskiy Maxim1, Turigin Anton1,
Morozovska Anna2, Eliseev Eugene2, and Kalinin Sergei3
1
Ferroelectric Laboratory, Ural Federal University, Ekaterinburg, Russia
2
Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine,
Kiev, Ukraine
3
The Center for Nanophase Materials Sciences and Technology Division,
Oak Ridge National Laboratory, Oak Ridge, TN, USA
Email: maxim.neradovskiy@labfer.usu.ru
Local polarization reversal under the action of local electric field produced by conductive tip ofscanning probe microscope has been studied in the vicinity of the existing flat domain wall in 30-mthick single crystalline plate of periodically poled congruent lithium niobate (CLN). The polarization
reversal has been carried out on different distances from existing domain wall.
Two modes of tip motion between switching points were used. Non-contact mode represents tip motion
at distance about 2 m over the sample surface. Polarization reversal at distances above 250 nm fromthe wall led to formation of isolated domains (Fig 1a) with linear dependence of radius on pulse
amplitude. Switching at distance < 250 nm from the wall led to round shaped shifts of the wall(Fig. 1b,c). Contact mode uses the motion of the grounded tip in contact with the surface. Formation ofprolate triangular shifts (length 350 nm) (Fig 1d) and nanodomain chains with period 100 nm (Fig 1e,f)
was observed for the tip motion across the wall.
The observed domain kinetics has been explained by polarization reversal under the action of residual
depolarization filed and stimulation of polarization reversal along the path of grounded SPM tip due toeffective external screening. Analytical and numerical simulations of the spatial distribution of residual
depolarization field in the vicinity of the isolated needle-like domain justified the proposed model.

Figure 1. Domain structures formed as a result of local switching near the flat 180o domain wall. (a) isolated
domains; (b), (c) round-shaped shifts of the wall; (d) prolate triangular shift; (e), (f) nanodomain chains.

The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has beenused. The research was made possible in part by RFBR (Grants 12-02-31377-mol-a, 13-02-01391-а, 1102-91066-CNRS-а), by Ministry of Education and Science (Сontracts 14.513.12.0006 and16.740.11.0585).

PFM-PA-17 _____________________________________________________________________________________________________________________

Size effect of the space charge modulation in semiconductor
caused by ferroelectric domain structure
Anna N. Morozovska,1 Eugene A. Eliseev,2 Olexander V. Varenyk3, andSergei V. Kalinin4,
1

Institute of Physics, National Academy of Sciences of Ukraine,
41, pr. Nauki, 03028 Kiev, Ukraine
2
Institute for Problems of Materials Science, National Academy of Sciences of Ukraine,
3, Krjijanovskogo, 03142 Kiev, Ukraine
3

Taras Shevchenko Kiev National University, Radiophysical Faculty
4g, pr. Akademika Hlushkova, 03022 Kiev, Ukraine
4
The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory,
Oak Ridge, TN 37831
Email: morozo@i.com.ua
We consider a typical heterostructure “domain patterned ferroelectric film  ultra-thin physical gap(dielectric layer)  semiconductor (electrolyte)”, where the semiconductor can be an incipient
ferroelectric, high-k narrow-gap semiconductors, covered with water adsorbents. Unexpectedly we havefound that the space charge modulation profile and amplitude in the semiconductor, that screens the
spontaneous polarization of a 180-degree domain structure of ferroelectric, nonlinearly depends on thedomain structure period a, dielectric layer thickness h and semiconductor screening radius Rd in a rather
non-trivial way. Multiple size effects appearance and manifestation are defined by the relationshipbetween a, h and Rd. Under the absence of the dielectric layer the space charge amplitude very slows
saturates to a spontaneous polarization value with the domain size increase. When the dielectric layer ispresent, the amplitude saturates to the smaller values, at that the saturation value essentially decreases
with the layer thickness increase, but the saturation rate is almost independent on the thickness in theactual range of parameters. The space charge amplitude strongly vanishes with the dielectric thickness
increase only for small domain period, but remains almost constant for wide domains. We show that theconcept of effective gap h* can be introduced in a simple way only for a single-domain limit. Depth
distribution of electric potential is nonlinear inside ferroelectric, while it is linear inside the dielectricand exponentially vanishes inside the semiconductor as anticipated. Obtained exact analytical results
open the way for understanding of complex current-AFM measurements of contaminated ferroelectricsurfaces in ambient atmosphere with moderate humidity.

PFM-PA-18 _____________________________________________________________________________________________________________________

Study of ferroelectric nanodomains in epitaxial PbTiO3 films by
PFM and Raman spectroscopy
Fedir Borodavka1, Ivan Gregora1, Ausrine Bartasyte2, Samuel Margueron3 and Jiří Hlinka1
1Institute of Physics, Prague, Czech Republic
2
Institute Jean Lamour, Nancy, France
3
Université de Lorraine and Supélec, Metz, France
Email: borodav@fzu.cz
Investigation of the domain structure in ferroelectric thin films is helpful for elucidating the interfacial
processes in these materials and for finding possible ways of their applications.
Domain structure of 320 nm thin films of ferroelectric lead titanate (PTO) grown using the metalorganic
chemical vapour deposition method (MOCVD) on TbScO3(TSO) and SmScO3(SSO) perovskite
substrates have been studied with the help of piezoresponse force microscopy (PFM) and Raman
spectroscopy techniques.
PFM (Fig.1) and Raman show that PTO films grown on SSO have preferentially a-domain orientation(in-plane orientation of spontaneous polarization PS), while films grown on TSO substrate havedominantly c-domain orientation (out-of-plane orientation of PS). The striking difference between thetwo domain structures can be assigned to the opposite sign of the epitaxial misfit strain at the deposition
temperature 650°C (a'TSO< a'PTO <a'SSO).

Fig. 28: PFM images of 320 nm thin PbTiO3 film on SmScO3 (a) and TbScO3 (b) substrates. Edges of thescanned area are roughly parallel to pseudocubic axes of the substrate.

PFM-PA-19 _____________________________________________________________________________________________________________________

Li diffusion and electrochemical activity in commercial LiMn2O4
battery cathode by Electrochemical Strain Microscopy
Sergey Luchkin1, Andrei Kholkin1, Nina Balke2
1

Dept. of Materials and Ceramics Engng. & CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
The Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee
37831, USA

2

Email: luchkin@ua.pt
Fast growth of popularity of green technologies leads to a wider use of Li batteries in applications that
require high power density. High charging and discharging rates result in intensive degradation ofbattery materials. Deep understanding of the degradation mechanisms associated with Li transport isessential to engineer new battery materials with long life and excellent reliability. These studies should
be done on a nanoscale to identify the defect sites responsible for degradation.For this, we used
Electrochemical Strain Microscopy (ESM) [1] , a technique similar to Piezoresponse Force Microscopy(PFM) where ionic diffusion is responsible for measurable surface displacements. Li diffusivity andelectrochemical activity was studied in commercial LiMn2O4 cathodes. Typical cathode consists of
LiMn2O4 oxide particles and conductive carbon black particles distributed in PVDF binder. In thecathodes we observed clear ESM response on the active oxide particles that is a representation of thelocal molar volume change caused by Li diffusion. Conductive nanoparticle distribution in the binder
PVDF was detected by PFM. We used both the ESM time voltage spectroscopes to measureelectrochemical activity of Li ions on the active particles. The obtained results are discussed based on
the current understanding of Li diffusion mechanism in Li cathode materials. This research was
supported by the European project «Nanomotion» (FP7-People-2011-ITN-290158). The authors
gratefully acknowledge A. Hugues-Yanis and D. Rosato (Robert Bosch GmbH) for providing samples
and valuable discussions.
1. A. N. Morozovska, E. A. Eliseev, N. Balke, and S. V. Kalinin, «Local probing of ionic diffusion byelectrochemical strain microscopy: Spatial resolution and signal formation mechanisms», J. Appl. Phys.
108, 053712, 2010.

PFM-PA-20 _____________________________________________________________________________________________________________________

Nanoscale Crystallization of Piezoelectric Polymer and
Its Electromechanical Properties Studied by
Atomic Force Microscopy
Gun Ahn1,2, Seungbum Hong1,2,Kwangsoo No1
1

2

Department of Materials and Science Engineering, KAIST, South Korea
Nanoscience and Technology Division, Argonne National Laboratory, USA
Email: hong@anl.gov, ksno@kaist.ac.kr

Piezoelectric polymers have attracted great attentions due to its potential applications to bio-compatible
actuators, wireless sensors, and energy harvesting devices. However, the crystallization process andsubsequent electrical poling, which are essential in realizing such devices, have been the most difficult
challenges. Here, we suggest a novel method to control the crystallization process by using atomic force
microscopy (AFM) equipped with a nanoscale tip of various coatings, which we can use to confine themechanical load, electrical field and temperature gradient. Furthermore, we will present the AFM tipinduced nanoscale crystallization under different ambient condition by changing the purging gas into asealed sample holder to study the impact of surrounding gas or water molecules on theelectromechanical properties of the piezoelectric polymers.

PFM-PA-21 _____________________________________________________________________________________________________________________

Measurement Anomaly of Step Width using
Atomic Force Microscopy
Gun Ahn1,2 , Dean J. Miller3, Kwangsoo No2, Seungbum Hong1,2
1

Nanoscience and Technology Division, Argonne National Laboratory, USA
2
Department of Materials and Science Engineering, KAIST, South Korea
3
Electron Microscopy Center, Argonne National Laboratory, USA
Email: hong@anl.gov, ksno@kaist.ac.kr

We imaged the topography of silicon grating having a pitch of 10 µm with different pixel pitch to findthe optimum resolution using atomic force microscopy (AFM). We found that the step width decreased
from 1300 to 108 nm and the step height increased from 172 to 184 nm when a pixel pitch in fast scan
axis decreased from 625 nm to 3.9 nm. We also measured the step width and height of etched silicongrating by a focused ion beam (FIB) using Scanning Electron Microscopy (SEM) and compared themeasured step height and width with AFM data. The obtained values from SEM image were 187.3 nm ±6.2 nm and 116 nm ± 10.4 nm,which were in agreement with AFM data with 39 nm and 23 nm of pixel
pitches, respectively. Lastly, our findings that RMS roughness varied less than 1 nm and converged atthe value of 77.6 nm with any pixel pitch suggest we can use the RMS roughness obtained with any
resolution. Based on the assumption that our results scale linearly with the size of the features ofinterest, we believe that one can use the optimal pixel resolution for fast and reliable topographyacquisition and surface roughness analysis.

PFM-PA-22 _____________________________________________________________________________________________________________________

Calibration and Correction of Signals in Piezoresponse ForceMicroscopy (PFM)
Leonard F Henrichs, Andrew J Bell
Institute for Materials Research, University of Leeds, Leeds, United Kingdom
Email: pmlfh@leeds.ac.uk
Piezoresponse force-microscopy (PFM) has become a very powerful technique to study ferroelectricdomains and probe local properties in polar materials. However, reliable data acquisition was often
reported to be difficult. This also poses a problem for quantitative data acquisition and in fact, most of
PFM data published to date are qualitative. The frequency-dependent background-signal that was foundby Soergel et al., was identified as one of the problems for reliable data acquisition. Here, we confirm
the existence and consequences of the background-signal. Furthermore, we show that other instabilities
in PFM also have a similar effect like the background-signal. A new calibration method is presented toquantify the X-Amplitude PFM signal and subtract the background-signal in a single step by using
periodically poled lithium niobate as a reference sample.
Furthermore, a simple scheme to generate background-signal free R-Amplitude and phase images out of
X-Amplitude images using a freeware software is presented.
The method of calibration and correction is applied to PFM images of several ferroelectric samples.

Fig. 29: Uncorrected (left) and corrected (right) PFMAmplitude of contaminated periodically poled lithium
niobate.

PFM-PA-23 _____________________________________________________________________________________________________________________

Roger Proksch1
1Asylum Research, USA
Piezoresponse Force Microscopy (PFM) and Electrochemical Strain Microscopy (ESM) have led to significant progress in
our understanding of the nano-electromechanical origins of functionality in a large variety of materials. For example,
hysteresis has been considered the “smoking gun” that demonstrates ferroelectricity in PFM measurements. The cantilever isan extended mechanical object with normal modes that depend on the boundary conditions both of the cantilever structure
itself and on the boundary conditions imposed by the tip-sample interactions. By using the encoded and motorized opticalbeam controls on a commercial microscope we have been able to directly measure the extended shape of the cantilever as it
interacts with various samples and in a variety of measurement modes. Integration of the laser scanning mechanism directlyin the AFM has enabled these shape measurements during normal AFM operation in a variety of imaging modes ranging
from force curves and contact modes to AC modes. This presentation will focus on contact and force curves measurement
modes. In many cases of interest, the response of a cantilever does not behave as a simple, single-mode system. To elucidate
the effects of local and long-ranged drive mechanisms on the multi-modal cantilever probe, the response of the cantilever as afunction of both frequency and optical beam spot position has been measured in-situ while the cantilever is directly probing afunctional material, either with PFM or ESM. Two interesting results are (i) the crossover between the dc and first contact
mode is measurable at surprisingly low frequencies, and (ii) contrary to initial expectations, operating on resonance actuallyprovides more stable and reliable quantification of the cantilever drive. This is explained in terms of the high Q-factor of theresonance. The crossover frequency is affected by the boundary conditions, specifically the tip-sample stiffness. Because ofthis, electrochemical interactions at the tip can lead to a measured change in the amplitude and phase of the cantilever, evenwhen the response of the sample remains unchanged. In particular, this in turn can cause measured 180 degree phase shifts inthe measured response. This phase shift – stemming from a change in the tip-sample stiffness – is indistinguishable from aphase shift originating from a change in the polarization of the sample. We will show simulations and experimental data that
illustrate this crosstalk. In addition, we will discuss methods to remove separate these two effects.

ISAF Student poster competition
Forum Hall
Monday, July 22 2013, 01:00 pm - 02:00 pm

ISAF-SPC-1 ____________________________________________________________________________________________________________________

Electric Field-Induced Deformation Behavior In Mixed
Bi0.5(Na0.8K0.2)0.5TiO3 and Bi0.5(Na0.385K0.09Li0.025)(Ti0.975Ta0.025)O3
Dae-Jun Heo, Chang-Ho Yoon, Changhyo Hong, Hyoung-Su Han, Hyun-Young Lee, and Jae-Shin Lee
School of Materials Science and Engineering, University of Ulsan, Ulsan, Republic of Korea
Email: hdj0804@hanmail.net
Recently, 0.82(Bi1/2Na1/2)TiO3-0.18(Bi1/2K1/2)TiO3 solid solution (BNKT) ceramics attract great attention becauseof their large electric field-induced strains (EFIS) at relaxor (R) – ferroelectric (FE) phase boundaries. However, acritical problem that hinders their practical application to actuators is probably originated from the fact that a highelectric-field required to induce the phase transition accompanying a large strain. In this study, a method to
reduce the field for the R-FE transition is proposed. This study investigated the electrical and EFIS properties of
BNKT ceramics-embedded Bi0.5(Na0.385K0.09Li0.025)(Ti0.975Ta0.025)O3 (BNKL-TT) ceramics, in which the fraction of
BNKT was varied from 0 to 30 wt%. The normalized strain Smax/Emax of a single phase BNKT-TT ceramics was
608 pm/V at 4 kV/mm, however, it was enhanced up to 761 pm/V by embedding 30 wt% BNKT particles.

(a)(b)
Fig. 1. Schematic of a relaxor ceramic matrix ferroelectric-relaxor composite (a) and its electric field-induced
strain behavior (b) in comparison with that of a homogeneous BNKT relaxor

ISAF-SPC-2 ____________________________________________________________________________________________________________________

Temperature Dependence of Domain Contributions to
Piezoelectric Activity in the Soft- & Hard-doped Lead Zirconate
Titanate and La-doped Bismuth Ferrite Lead Titanate Systems
Sayyed Adam Qaisar1, Andrew J Bell2, Timothy P Comyn3
1Institute for Materials Research, University of Leeds, Leeds, United Kingdom
Email: s.a.qaisar06@leeds.ac.uk

Previous investigations have established the significance of the Rayleigh law to explaining intrinsic andextrinsic contributions to activity in piezoelectric ceramics[1–4]. Typically investigations of domain wall
contributions to the piezoelectric effect require the use of synchrotron time. Presented is a technique using a
combination of weak-signal & direct-effect measurements in addition to electrical characterization to elude
to the reversible and irreversible domain contributions to the piezoelectric effect in lead zirconate titanate(PZT) and bismuth ferrite lead titanate (BFPT) systems.
A new experimental apparatus has been constructed, allowing for investigation of cycling electric field &stress effects at selected temperatures on the degradation of d33 in piezoelectric materials. Furthermore, thedevice has been used to investigate the intrinsic and extrinsic contributions to the direct piezoelectric effectin PZT & La-doped BFPT. Supported by using weak-signal measurements, the domain wall behaviour andpiezoelectric activity at elevated temperatures has been investigated for these material systems in addition toactivity degradation.
Data from the new apparatus is presented and further discussed in relation to previously observed behaviour
in PZT[5][6][7], highlighting the enhanced mechanical properties of BFPT over PZT and comparing thetemperature dependence of domain contributions in both material systems[1]
D. Damjanovic and M. Demartin, Journal of Physics: Condensed Matter, vol. 9, no. 23, pp. 4943–
4953, Jun. 1997.
[2]

R. E. Eitel, T. R. Shrout, and C. A. Randall, Journal of Applied Physics, vol. 124110, 2006.

[3]

A. Pramanick, D. Damjanovic, J. E. Daniels, J. C. Nino, and J. L. Jones, Journal of the American
Ceramic Society, vol. 94, no. 2, pp. 293–309, Feb. 2011.

[4]

M. Davis, D. Damjanovic, and N. Setter, Journal of Applied Physics, vol. 084103, 2006.

[5]

J. Nuffer, Acta Materialia, vol. 48, no. 14, pp. 3783–3794, Sep. 2000.

[6]

H. Wang, A. a. Wereszczak, and H.-T. Lin, Journal of Applied Physics, vol. 105, no. 1, p. 014112,
2009.

[7]

M. Liu and K. J. Hsia, Applied Physics Letters, vol. 83, no. 19, p. 3978, 2003.

ISAF-SPC-3 ____________________________________________________________________________________________________________________

General Behavior of Soft Mode and Central Mode in Strained
SrTiO3/DyScO3 multilayers
Volodymyr Skoromets1, Christelle Kadlec1, Jürgen Schubert2, Gregor Panaitov2, and Petr Kužel1
1

Department of dielectrics, Institute of Physics, Academy of Sciences of the Czech Republic, Prague,
Czech Republic
2
Institute of Bio and Nanosystems, Research Centre Jülich, JARA-Fundamentals of Future Information
Technology, Jülich, Germany
Email: skoromet@fzu.cz

109
110

-1

90

0 kV/cm

75

)

(a)

n=2
n=4
n=6

60
45

125

175
225
Temperature (K)

(b)

62

275 K

58

)

66
-1

The time-domain THz spectroscopy was used tomeasure the temperature and electric-fielddependence of the complex dielectric spectra of thesamples. Two main features are observed: aferroelectric SM and a central mode (CM), which aredescribed by a general model consisting of aharmonic oscillator coupled with a Debye relaxation.
The SM frequency 0(T,E) is the key parameter
which describes the temperature (T) and electric-field(E) evolution of the permittivity; some examples ofthe behavior of 0 are shown in Fig. 1. A
comprehensive comparison of the dielectric behavior
of all the structures and the underlying latticedynamics will be discussed in the conference
contribution.

105

0 (cm

It is known that the strain induced by the substrategradually relaxes with increasing thickness of thefilm. To overcome this problem we prepared several
heterostructures consisting of n×STO/DSO bilayerson (110) DSO substrates by pulsed laser deposition.
The thickness of each individual layer is of 50 nm,
since the strain relaxation mainly occurs for thicker
STO films110. The DSO layers are intended tomaintain the strain over an increased total STO
thickness (n = 2–8). Interdigitated metallic electrodestructure deposited on each sample allowed
application of a bias electric field.

0 (cmStrontium titanate (SrTiO3, STO) single crystal is an incipient ferroelectric; its THz and sub-THz dielectric
behavior is nearly entirely governed by the ferroelectric soft mode (SM). Is has been shown109 that theferroelectric phase transition can be induced near the room temperature in strained epitaxial STO films if thesubstrate is suitably chosen, e.g. DyScO3 (DSO).

275

54
50
0

20
40
Electric field (kV/cm)

60

Fig. 30: (a) Temperature (at 0 kV/cm) and (b) fielddependence (at 275 K) of the SM frequency forselected samples. Arrows denote the phasetransition.

J. H. Haeni et al., “Room-temperature ferroelectricity in strained SrTiO3”, Nature, vol. 430, p. 758-761 , 2003

Z. Y. Zhai et al., “Dislocation density and strain distribution in SrTiO3 film grown on (110) DyScO3 substrate”, J. Phys. D:
Appl. Phys., vol. 42, 105307, 2009

ISAF-SPC-4 ____________________________________________________________________________________________________________________

Fabrication and characterization of BaTiO3 ultrathin ferro-electric
layers to investigate the origin and characteristics of domain wall
conductivity.
Alan Douglas1, Li-Wu Chang1, Marty Gregg1
1

Centre for Nanostructured Media, Queens University Belfast, Belfast, Northern Ireland
Email: adouglas08@qub.ac.uk

An investigation into the fabrication and characterization of ferroelectric heterostructures was carriedout. The materials of choice were a combination of ultrathin Barium Titanate (BTO) and Strontium
Ruthenate (SRO), a ferroelectric and bottom electrode layer respectfully; these layers were deposited ona substrate of Strontium Titanate (STO) by Pulsed Laser Deposition (PLD).
The films were then characterized by in-house measurements through Atomic Force Microscopy(AFM), Piezoresponse Force Microscopy (PFM), Transmission Electron Microscopy (TEM), and X-Ray
Diffraction (XRD). Such techniques allowed the fabrication method to continually be adapted until the
production high quality ultra-thin ferroelectric BTO films was achieved.
Domains and domain walls within the ultrathin ferroelectric layer were then investigated using both
PFM and Scanning Tunneling Microscopy (STM), with the intention of being able to measure domain
wall conductivity and investigate the factors which control conductivity. The use of STM has not been
widely utilized for domain wall studies111 but should allow both high-resolution conductivity mappingand direct probing of the densities of states within the domain walls.
Striving for a better understanding and control over ferroelectric domain walls will no doubt prove ofuse, as it will enable us to better integrate such components into an newly emerging generation ofnanoscale electronic devices.

1. Chiu, Y.P. et al. "Atomic-Scale Evolution of Local Electronic Structure Across Multiferroic Domain Walls." Advanced
Materials 23, 1530–1534 (2011).

ISAF-SPC-5 ____________________________________________________________________________________________________________________

Compositional dependence of PMN-PT thin films prepared by
combinatorial sputtering
Fumiya Kurokawa1, Kohei Tomioka2, Hirotaka Hida1, Isaku Kanno1
1

Mechanical Engineering, Kobe University, Kobe City, Hyogo, Japan
2
Micro Engineering, Kyoto University, Kyoto City, Kyoto, Japan
Email: funyayorozu1112@gmail.com

In this study, we deposited Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) thin films on Pt/Ti/Si substrates bycombinatorial sputtering to optimize the composition ratio of PMN-PT thin films. We confirmed that
relative dielectric constants increase with decreasing PT ratio in PMN-PT films. On the other hand, thePMN-PT thin films showed the maximum piezoelectric coefficients |e31,f | = 7 ~ 8 C/m2 around PMN0.45PT.

Fig.1 Relative dielectric constants of PMN-PT thin Fig.2 Piezoelectric coefficient |e31,f | of PMN-PT thinfilms dependence on compositional ratio
films dependence on compositional ratio

Optimization of PMN/PT compositional ratio is one of important parameters for PMN-PT thin films tomaximize piezoelectric properties. In this study, we deposited PMN-PT thin films by combinatorial
sputtering and evaluated compositional dependence of dielectric and piezoelectric properties
precisely112. Compositional gradient PMN-PT thin films were deposited by multi target co-sputtering,and pyrochlore-free PMN-PT thin films with random orientation were prepared on Pt/Ti/Si substrates.
PT compositional ratio is ranging from 0.25 to 0.57, which covered MPB composition of bulk PMN-PT
ceramics113. Measurement results of relative dielectric constants and transverse piezoelectric coefficients|e31,f | dependence on PMN/PT compositional ratio are shown in Fig.1 and Fig.2. Relative dielectric
constants increase with decreasing PT ratio, and peaked at around PMN-0.30PT which is consistent with
the MPB composition of bulk PMN-PT ceramics. On the other hand, piezoelectric coefficient shows
maximum value |e31,f | = 7 ~ 8 C/m2 at PMN-0.45PT, which is shifted from MPB composition of PMNPT bulk ceramics. This shift phenomenon might be attributed to residual stress of resulting PMN-PT
thin films.
112

K. Tomoika, et al, “Composition dependence of piezoelectric properties of Pb(Zr,Ti)O 3 films prepared by combinatorial
sputtering”, Jpn. J. Appl. Phys., vol. 51, 09LA12, 2012.
113

B. Noheda, et al, “Phase diagram of the ferroelectric relaxor (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3”, Phys. Rev. B., vol. 66,
054104, 2002.

ISAF-SPC-6 ____________________________________________________________________________________________________________________

Processing ceramic (Bi,Sm)FeO3: comparing two methods ofsynthesis by microstructure, phase evolution, polarization andstrain behavior
Julian Walker1,3, Peter Bryant2, Valsala Kurusingal2, Charles C. Sorrell1,
Tadej Rojac3 and Nagarajan Valanoor1
1

Materials Science and Engineering, University of New South Wales, Sydney, NSW, Australia
2
Thales Australia, Rydalmere, Sydney, NSW, Australia
3
Jozef Stefan Institute, Ljubljana, Slovenia
Email: julian.walker@unsw.edu.au2

P o la r iz a t io n ( u C /c m )Samarium substitution in bismuth ferrite (Bi,Sm)FeO3 has been studied as a means of inducing amorphotropic phase boundary between polar rhombohedral R3c and non-polar orthorhombic Pnma
structures. In such compositions there have been observations of enhanced remnant polarization,
reduced coercive field and increased piezoelectric response with respect to pure BiFeO3. However theseproperties are published for thin film materials, while
for bulk ceramics the switching behavior, which ismost often studied by means of polarization- and40strain-electric-field hysteresis loops, and the weak20
field piezoelectric response, are mostly unknown.
-2 0 0-1 0 0

100
-2 0

200

In this work we present details of two processing
-4 0
0 .2
methods utilizing surfactant addition during milling to
0 .1
reduce agglomerate formation and improve
homogeneity of oxide mixtures. While both methods-2 0 0 -1 0 0
100
200
use a reaction sintering technique one method- 0 .1
involves the use of mechanochemical activation toenhance homogeneity and reactivity of mixtures. We
E le c tr ic fie ld (k V /c m )show that activation effectively reduces theFig. 31: Strain-electric-field hysteresis loop of
temperatures required to complete the diffusion ofreaction sintered (Bi0.88Sm0.12)FeO3 measured at 220
Sm+3 into the R3c crystal structure.
kV/cm and 0.1Hz. Insert: Polarization-electric-field
These processing methods can produce samples withloop at 160 kV/cm and 100Hz for the samehigh dielectric breakdown (> 180kV/cm) at fields
composition.
more than double the coercive field (≈80kV/cm). At
these high fields we measured large strains of up to
0.3 % within the range of 0.1-100 Hz frequencies (Fig. 1.), while polarization loops up to 500 Hz
display moderate leakage and good saturation (insert of Fig. 1.). Previously piezoelectric data for these(Bi,Sm)FeO3 systems have been obtained only from thin films and we now provide for the first time, acomprehensive study of piezoelectric behaviour also in bulk ceramic materials.
S tra in (% )E le c tr ic f ie ld ( k V /c m )ISAF-SPC-7 ____________________________________________________________________________________________________________________

Textured K0.5Na0.5NbO3 thin films by aqueous chemical solution
deposition on SrTiO3 substrates
Ky-Nam Pham1, Maxim Morozov1, Thomas Tybell2, Tor Grande1, Mari-Ann Einarsrud1
1

Department of Material Science and Engineering, Norwegian University of Science and Technology,
Trondheim, Norway
2
Department of Electronics and Telecommunications, Norwegian University of Science andTechnology, Trondheim, Norway
Email: pham.ky-nam@ntnu.no

The search for lead-free alternatives to PZT materials is currently going on worldwide. Na 0.5K0.5NbO3(KNN) thin films were fabricated on (100) and (110) oriented SrTiO 3 substrates by chemical solution
deposition. Stable environmentally friendly aqueous KNN precursor solutions were prepared from Naacetate, K-acetate and Nb-ammonium oxalate and deposited onto SrTiO3/Nb:SrTiO3 substrates by spin
coating at 2500-3000 rpm for 20-40 s. The films were dried at 200 oC for 2 min using a hotplate andthen pyrolysed at 400 oC for 5 min. The film thickness could be controlled by repeating the spin coatingprocedure. The final films were sintered at 600-900 oC for 5 min in oxygen by rapid thermal processing(RTP) with heating rate of 40 oC/s. To aid texturing of the KNN-based films, Dissolution/reprecipitationof KNN in a molten mixture of NaCl/KCl was tested to enhance texturing by incorporating salts in thesolution or deposition of salt layers between the KNN layers, which could be washed away after thethermal treatment.
Homogeneous films with an average grain size down to 60 nm were prepared after heat treatment at 900
oC. The high degree of texture was confirmed by XRD, Fig. a). The intensity of the KNN (100)reflection for films on (100) oriented substrates increased with increasing sintering temperature up to
900 oC, while for KNN films deposited on (110)-oriented substrate the (110) reflect that texture could becontrolled by the crystal orientation of the substrate.

The ferroelastic and piezoelectric properties of the film was confirmed by PFM, see Fig. b) and c).
Local piezoelectric properties of selected films will be discussed in relation to the processing
conditions, effect of the molten salts, microstructure and orientation of the substrate. The highdegree of texture and the fine-grained microstructure of the KNN nano-crystalline thin films
demonstrate that this environmentally friendly synthesis method is applicable for fabrication of
textured lead-free ferroelectric thin films.
Fig. 32: (a) XRD patterns for the KNN thin film deposited on (100) SrTiO3 substrate, sintered at various
temperature as well as local piezoresponse (b) amplitude, (c) phase of the KNN thin films was sintered at
800 oC.

ISAF-SPC-8 ____________________________________________________________________________________________________________________

Growth and Piezo-/Ferroelectric Properties of Pb(Mg1/3Nb2/3)O3PbTiO3-Bi(Zn1/2Ti1/2)O3 Ternary Single Crystals
Reagan Belan, Hamel Tailor, Zuo-Guang Ye
Department of Chemistry and 4D LABS, Simon Fraser University,
Burnaby, BC, V5A 1S6, Canada
Email: rab11@sfu.ca
Single crystals of relaxor-based perovskite solid solutions, namely Pb(Mg1/3Nb2/3)O3–PbTiO3[PMN-PT] and Pb(Zn1/3Nb2/3)O3–PbTiO3 [PZN-PT], show extraordinary piezoelectric performance,
enabling them to be the leading choice of materials for the next generation of electromechanicaltransducers in a broad range of applications1. However, these materials suffer from somedrawbacks, in particular, a low Curie temperature (TC) and a low coercive field (Ec). In order toovercome these shortages, Bi(Zn1/2Ti1/2)O3 [BZT] was added to ‘harden’ the PMN-PT system andthe ternary solid solution system of Pb(Mg1/3Nb2/3)O3‒PbTiO3‒Bi(Zn1/2Ti1/2)O3 [PMN‒PT‒BZT]
was prepared in our laboratory in the form of ceramics and single crystals2,3. In this work, we report
the growth of the single crystals of this ternary solid solution by the high temperature solution(flux) method using a PbO and H2BO3 mixture as flux. By varying both the temperature profile of
the growth and the nominal composition of charge, large and good-quality multinucleated crystalsof PMN‒PT‒BZT were obtained. The domain structure and phase transitions of the PMN‒PT‒BZT
crystals are characterized by polarized light microscopy (PLM) and piezoresponse force microscopy(PFM), providing insights into the crystal growth behavior of the ternary system. The dielectric andferroelectric properties of the crystals are also investigated, confirming that the ternary single
crystals exhibit enhanced piezoelectric performance compared to their ceramic counterparts.
This work is supported by the Office of Naval Research (Grants No. N00014-11-1-0552 andN00014-12-1-1045) and the Natural Science and Engineering Research Council of Canada.
1Z.-G. Ye, Mater. Res. Soc. Bull., Vol. 34, No. 4 , pp. 277-283 (2009).
H. N. Tailor, A. A. Bokov, Z.-G. Ye, Ferroelectrics, 405, 67-75 (2010).
3
R. Belan, H. N. Tailor, X. Long, A. A. Bokov and Z.-G. Ye, J. Cryst. Growth, 318, 839-845 (2011)2

ISAF-SPC-9 ____________________________________________________________________________________________________________________

Enhanced Flexoelectric Effect in a Non-ferroelectric composite
Yong Li1, Hong Wang1, Feng Xiang1, Longlong Shu1, Xiaoyong Wei1
1

Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education,
Xi’an Jiaotong University, Xi’an 710049, China
Email: liyong0509@stu.xjtu.edu.cn

Direct flexoelectric effect was investigated in a non-ferroelectric composite(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7/Ag (BZN/Ag) where the structure symmetry ∞∞m permits no macropiezoelectricity. The flexoelectric coefficient of the BZN/Ag composite was measured using beam
bending method at room
temperature and the value is up
to 0.4C/m. This value is 3-4
orders magnitude higher thanthose of common dielectrics.
In the past few years, most of theresearches on flexoelectricity
were focused on ferroelectrics.
We first experimentally studied
the flexoelectric effect in nonferroelectrics. In our research, thecomposite of BZN+15%vf Ag
Fig. 1: The linear fit of flexoelectric polarization as
a function of applied strain gradient measured at
was prepared by solid state
23℃.The slopes of the lines are separately thesintering method. The dielectric
flexoelectric coefficients u12 of BZN+15%vf
constant of the composite isAg(0.403uC/m) and pure BZN( nearly zero).
above 720, and the loss below 6% at thefrequency of 1kHz. The doping of silver to
BZN enlarged the permittivity and γ value of the composite, making the flexoelectric effectenhanced.
Our study indicates that non-ferroelectrics can also have enhanced flexoelectric effect and thatcomposite materials with high flexoelectric effect can be designed.

ISAF-SPC-10 ___________________________________________________________________________________________________________________High frequency magneto-impedance effects in
multiferroic CoTiO2-Bi4Ti3O12 multilayer films

Hanae Kijima1,3, Zhang Yiwen1, Nobukiyo Kobayashi2, Shigehiro Ohnuma1, 2,Nava Setter3, Paul
Muralt3 and Hiroshi Masumoto1
1

Center for Interdisciplinary Research, Tohoku University, Sendai, Japan
Research Institute for Electromagnetic Materials RIEM, Sendai, Japan
3
Laboratoire de Céramique, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
2

Email: kijima@cir.tohoku.ac.jp
Multiferroic thin film structures are of great interest for applications in the lower GHz frequency
range. In our study, we combine soft magnetic thin films exhibiting a strong magneto impedance(MI) effect with ferroelectric thin films. The impedance change upon application of an external
magnetic field (Hex) is supposed to occur also in magnetic-ferroelectric multilayers. It is expectedthat the MI effect can be suitably enhanced at magnetic resonances occurring at a few GHz.
In expectation of high permeability (μ) and dielectric permittivity(ε) at GHz frequencies, CoTiO2 and Bi4Ti3O12 are selected for thesoft magnetic and dielectric layers, respectively. In this study, we
present a strong resonance effect in µ measurements, and asignificant magneto-impedance effect in CoTiO2- Bi4Ti3O12
multilayer films in the frequency range of 0.1-10 GHz at room
temperature.
50 nm thick ferromagnetic CoTiO2 layers were intercalated with
Bi4Ti3O12 dielectric thin films. Both were grown by rf magnetron
sputtering. The frequency dependence of μ was investigated byusing the shielded parallel line method in the frequency range of
0.1-10 GHz. The Hex was applied parallel to rf-magnetic field in thefilm plane. For the high frequency impedance analysis, micro MIM
capacitors were fabricated by lithography and wet etchingprocesses. The complex admittance (Y = G+iB) of the film undervarious Hex were measured by using calibrated 50 Ohm probes forthe desired frequency range. The measurements are carried out atroom temperature.
Figure 1 presents the frequency dependence of real and imaginary
part of μ, and G and B of CoTiO2- Bi4Ti3O12 multilayer films atvarious H-fields Hex. The μ” shows a clear peak at theferromagnetic resonance (fr) at 3.76 GHz. The intensity of the peakdecreases from 94.8 to nearly zero when applying a Hex of 334 Oe.
Interestingly, G and B values around fr also change with varying
Hex. The maximum increase of B (by 12.3 %) was observed at 3.76
GHz in a magnetic field of Hex = 96 Oe.
Acknowledgement

Fig. 33: The frequency
We wish to thank Dr. S. Takada for his cooperation of high dependence of μ’(a), μ” (b), G
frequency μ measurement. The authors would like to thank for (c) and B(d) measured atmuch help and technical assistance of Mr. R. M. Aghdam (EPFL), various values of Hex.

Mr. M. Murakami (RIEM) and Mr. M. Iwasa (RIEM).

ISAF-SPC-11 ___________________________________________________________________________________________________________________

Large and stable actuation strain by reversible 90o domain
switching in 0.62%PMN-0.38%PT crystal under electromechanicalloading
Yingwei Li, Faxin Li
State Key Lab for Turbulence and Complex Systems, College of Engineering, Peking University,
Beijing, 100871, China
Email: yingweili@pku.edu.cn
Ferroelectric actuators are characterized by their peculiar electromechanical energy conversion
efficiency, ultra-fast response, and compact size, etc. However, their wide application is limited by
the small piezoelectric strains of ferroelectric materials. Therefore, intensive efforts have been madein this aspect. The biggest breakthrough was achieved by Park and Shrout in 1990s. They obtainedlarge actuation strains of ～1.7% in relaxor ferroelectric crystals via phase transformation.
However, the actuation ability of relaxor ferroelectric crystals decreases to 0.2～0.4% within the
up-operation field limit in the vicinity of 1.5～2.0kV/mm. Large reversible actuation strains of～0.8% were also realized by using the huge strain accompanied with 90o domain switching via
point-defect mediation or via electromechanical loading. For the former, further investigations
concerned its stability is still needed before utilizing due to the intrinsic dissipation property of thepoint defects. As for the latter, their practical applications were inconvenienced by the compressive
stress sensitivity of the actuation strains, the brittleness of BaTiO3 crystals, and the requirement oflarge bipolar field power amplifier. Here we report that a pre-poled 0.62%PMN-0.38PT crystal cangenerate large strains of 0.65% at uni-polar electric fields of 1.8kV/mm with uniaxial precompression. Such large strains stem from the reversible 90o domain switching under thecompetition between compressive stresses and electric fields. Additionally, the actuation strain isstable. It only decreases about 7.7% after one thousand cycle’s electric fields loading. On the other
hand, the actuation strains can be larger than 0.42% in a wide range of compressive stresses(12MPa～40MPa). These characteristics make it suitable for practical applications.

Fig 1. (a) Electric field vs. strain (E-S) curves for PMN-PT crystal during unipolar electric fields
loading at different levels of compressive stress, (b) Evolution of the electric field vs. strain curveunder cycle’s electric fields loading (The compressive stress is at 20MPa).

ISAF-SPC-12 ___________________________________________________________________________________________________________________A MEMS AlN transducer array for use as a cochlear implant
Katherine Knisely and Karl Grosh
Mechanical Engineering, University of Michigan, Ann Arbor, MI
Email: kknisely@umich.edu
Aluminum nitride (AlN) has emerged as an excellent material for a variety of MEMS applications
because of its high electrical resistance, low dielectric loss, and high sound velocity. Recently,
MEMS sensors using AlN in a bimorph cantilever configuration have been demonstrated with low
noise floors and good sensitivity114. Because of its very low dielectric loss factor and relatively
simple deposition process as a thin film, AlN is an excellent material for microphones. The
cantilever configuration has many benefits, including a more linear response, control of thefrequency response using simple changes to the beam geometry, and simple adaptation frommicrophone to hydrophone.
We present an array of AlN bimorph cantilevers, fabricated using MEMS batch processing
techniques, with applications both as a hydrophone array and as a completely implantable cochlear
implant (CI).
A silicon backbone supports five 400μm wide, 5μm thick bimorph(Platinum/aluminum nitride (AlN) stack) cantilevers, each of which is designed to have aresonance, in water, that corresponds to its tonotopic locationin the guinea pig cochlea (20-40kHz). A 1mm wide, 10μm
thick parylene and gold ribbon cable extends 3cm from theprobe to an electrode bay, where electrical connections toeach cantilever are accessed. The frequency response of a
cantilever in a viscous fluid is predicted using a modified
Euler-Bernoulli equation that includes fluid loading andviscous damping115, and is measured in air using a laser
vibrometer and in water using a calibrated underwatertransducer pair.

Fig. 34: The fabricated device. The

Unlike traditional CIs, this probe is designed to transduce cantilever array (left, circled, with amechanical vibrations of the cochlear fluid into electrical closeup on the right ) is connected tosignals that stimulate the auditory nerves without the use of an an electrode bay for external electricalexternal sound processing unit. Vibrations in the cochlear monitoring by a flexible parylene-gold
fluid deflect the cantilevers, resulting in a potential forming ribbon cable.
on the outer electrode layers of the cantilever. The outerelectrodes are in electrical contact with the ionic fluid of the cochlea, producing a current in thecochlear fluid that is passed to the auditory nerves. In this design the energy is locally sensed andconverted into stimulation within the cochlea, therefore our design does not require the traditionalsignal processing unit, microphone, and transceiver that current CIs employ. Benefits of this design
include lower power, smaller size, and lower latency when compared with current commercial CIs.

114
115

R. Littrell and K. Grosh, Journal of Microelectromechanical Systems 21(2), 406 (2012).
JE Sader. Journal of. Applied Physics, 84:64–76, 1998.

ISAF-SPC-13 ___________________________________________________________________________________________________________________

Piezoelectric Films for High Density Switching Arrays for Logic
R. Keech1, S. Shetty1, S. Trolier-McKinstry1, D. Newns2, and G. Martyna2
Department of Materials Science and Engineering, Pennsylvania State University
Millennium Sciences Complex, State College, PA, 16802
2
IBM TJ Watson Research Center
Yorktown Heights, PA 10598

1

A fast, low power, transistor-type switching device has been proposed in which piezoelectric andpiezoresistive materials are employed in a stacked sandwich structure of nanometer dimension.
Of particular interest to this program is the functionality of the high aspect ratio piezoelectric
70Pb(Mg1/3Nb2/3)O3-30PbTiO3 (PMN-PT) component. Dense PMN-PT films of approximately
350 nm in thickness were made by a 2MOE solvent sol-gel route. These films were phase pureand strongly 100 oriented by XRD with dielectric constants exceeding 1300 and loss tangents ofapproximately 0.01. The films showed slim hysteresis loops with remanent polarizations of about
10 μC/cm2 and breakdown field of over 1500 kV/cm. The films exhibited large signal strain ofover 1% with clamped, large signal d33,f of approximately 90 nm/V. Reactive ion etching (RIE)
has been employed to pattern features in the PMN-PT film down to one micron in spatial scalewith vertical sidewalls. Upon lateral scaling, a small increase in small signal electrical properties
has been observed. The paper will describe the evolution in properties that develop as the films
are further laterally subdivided into small driving pixels.

Corresponding author:
Ryan R. Keech
Department of Material Science and Engineering
Pennsylvania State University
N-225 Millennium Science Complex
State College, PA, 16801
Phone: (207) 651-8804
E-mail: ryk5144@psu.edu

ISAF-SPC-14 ___________________________________________________________________________________________________________________

Pb(In1/2Nb1/2)-Pb(Mg1/3Nb2/3)-PbTiO3 single crystal monomorph
with perpendicular electrode connections for sensing andenergy harvesting
Ming Ma, Zhenrong Li, Zhuo Xu, Xi Yao
Electronic Materials Research Laboratory, Key Laboratory of Education Ministry; International
Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China
Email: zhrli@mail.xjtu.edu.cn
Piezoelectric monomorph, which has only one element, is one kind of potential structure forpiezoelectric applications in some extreme conditions. However the traditional parallel electrodeconnection is not effective for sensing and energy harvesting because of the restriction of the strain
neutral layer. In this paper, the perpendicular electrode connections were used to make themonomorph avoid the restriction of the strain neutral layer. And Pb(In1/2Nb1/2)-Pb(Mg1/3Nb2/3)PbTiO3 single crystal monomorph with perpendicular electrodes was studied. By comparing sevenforms of perpendicular electrode connections with the traditional parallel electrode connection, thewhole superposed perpendicular electrode connection is considered as the optimal output way forthe monomorph. The 27.2V peak to peak voltage in open circuit and the 71.5μW maximum powerwith the matching resistance at the resonance frequency can be produced by the whole superposed
perpendicular electrode connection, which are much more than 3.2V and 1.5μW that produced by
the parallel electrode connection.

ISAF-SPC-15 ___________________________________________________________________________________________________________________

Al1-xScxN thin films as promising non-ferroelectric materials forenergy harvesting
Ramin Matloub1, Gilles Moulard2, Thomas Metzger2 and Paul Muralt1
1

Ceramics Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
2

TDK-EPC Corporation, Munich
Email: ramin.matloub@epfl.ch

Aluminum nitride (AlN) thin films have become a standard material for RF filters in mobile
phones exploiting thickness mode resonances based on the longitudinal piezoelectric effect.
Recently it was shown that by partial substitution of Al by Sc, a factor 4 increase of thislongitudinal effect was observed in Sc0.43Al0.57N (Akiyama et. al). The question is how much thetransverse piezoelectric effect is increasing in ScxAl1-xN alloys. This is of interest for many MEMS
applications including vibration energy harvesting. In this case the coefficient of interest is e31,f
describes the stress that can be created in the film plane (coordinates 1, 2) of a parallel plate
capacitor structure under the condition that the film is free to move in the third direction (vertical to
the film plane). In this work, the transverse piezoelectric coefficient, e31,f , of Al1-xScxN thin films
was investigated as a function of composition. It increased by nearly 50 % from x=0 to x=0.17. As
the increase of the dielectric constant is only moderate we observed a more than 60 % increase of
the electrical energy content to be harvested. The energy harvesting FOM of 18.0 (GJ/m3) for
Al0.83Sc0.17N is comparable to good PZT thin films with an e31, f of 16 C/m2 and a dielectric constantof 1600. We shall show that the harvesting efficiency is potentially increased by more than 60 % ascompared to pure AlN. Going to even higher Sc concentrations, a doubling of the harvested power
is conceivable.

Ferroelectrics Awrads, ISAF Plenary Talk
CH
Tuesday, July 23 2013, 08:30 am - 10:00 am

Plenary II-1 _____________________________________________________________________________________________________________________

Piezoelectric Actuator Renaissance
Kenji Uchino
ONR Global-Asia, Office of Naval Research, Roppongi, Minato-Ku, Tokyo 106-0032, Japan; &Int’l Ctr. for Actuators & Transducers, The Penn State Univ., University Park, PA 16802, USA
Email: kenji.uchino.ngo@mail.mil & kenjiuchino@psu.edu
Actuator applications of piezoelectrics started in late 1970s, and enormous investment was installed
on practical developments during ‘80s, aiming at consumer applications such as precision
positioners with high strain materials, multilayer device designing and mass-fabrication processes
for portable electronic devices, ultrasonic motors for micro-robotics and smart structures. After theslump due to the worldwide economic recession in late ‘90s, we are now facing a sort of“Renaissance” of piezoelectric actuators according to the social environmental changes. This paper
reviews the recent advances in materials, designing concepts, and new applications of piezoelectric
actuators, and describes the future perspectives of this area.
The 21st century faces to a “sustainable society”. Global regulations are strongly called on
ecological and human health care issues, and the government-initiated technology (i.e., “politicoengineering”) has become essential. Because of significantly high energy efficiency of
piezoelectrics in comparison with other actuators such as chemical engines and electromagnetic
components, piezoelectric actuators have been re-focused most recently in the sustainable society(i.e., “Renaissance” in piezoelectric actuators).
I will discuss five key trends in this paper for providing the future perspectives; “Performance toReliability”, “Hard to Soft”, “Macro to Nano”, “Homo to Hetero” and “Single to Multifunctional”. First in the materials trend, the worldwide toxicity regulation is accelerating thedevelopment of Pb-free piezoelectrics for replacing the conventional PZTs. Second, high power
piezoelectrics with low loss have become a central research topic from the energy-efficiency
improvement viewpoint; that is to say, “real (strain magnitude) to imaginary performance (heatgeneration reduction)”. Third, we are facing the revival polymer era after ‘80s because of theirelastically soft superiority. Larger, thinner, lighter and mechanically flexible human interfaces are
the current necessity in the portable electronic devices, leading to the development in elastically soft
displays, electronic circuits, and speakers/microphones. Polymeric and polymer-ceramic composite
piezoelectrics are reviving and commercialized. PZN-PT or PMN-PT single crystals became
focused due to the rubber-like-soft piezo-ceramic strain after 25 years of the discovery. In the
MEMS/NEMS area, piezo MEMS is one of the miniaturization targets for integrating the piezoactuators in a micro-scale devices, aiming at bio/medical applications for maintaining the humanhealth. “Homo to hetero” structure change is also a recent research trend: Stress-gradient in terms ofspace in a dielectric material exhibits piezoelectric-equivalent sensing capability (i.e.,“flexoelectricity”), while electric-field gradient in terms of space in a semiconductive piezoelectric
can exhibit bimorph-equivalent flextensional deformation (“monomorph”). New functions can berealized by coupling two effects. Magnetoelectric devices (i.e., voltage is generated by applying
magnetic field) were developed by laminating magnetostrictive Terfenol-D and piezoelectric PZTmaterials, and photostriction was demonstrated by coupling photovoltaic and piezoelectric effects in
PLZT. In the application area, the global regime for “ecological sustainability” particularly
accelerated new developments in ultrasonic disposal technology of hazardous materials, diesel
injection valves for air pollution, and piezoelectric renewable energy harvesting systems.

Marija Kosec Memorial Electroceramic Processing
CLUB A
Tuesday, July 23 2013, 10:30 am - 12:00 pm
Chair:

Nava Setter
Swiss Federal Institute of Technology – EPFL, nava.

ISAF2-D1-1 _____________________________________________________________________________________________________________________

Mechanochemistry as an Efficient Way to Chemically
Homogeneous Ferroelectric Ceramics: Case Studies of(K,Na)NbO3- and BiFeO3-Based Materials
Tadej Rojac1,2, Andreja Bencan1, Dragan Damjanovic3, Barbara Malic1
1

Electronic Ceramics Department, Jozef Stefan Institute, Ljubljana, Slovenia
2
CoE NAMASTE, Ljubljana, Slovenia
3
Ceramics Laboratory, Swiss Federal Institute of Technology – EPFL, Lausanne, Switzerland
Email: tadej.rojac@ijs.si
Dedicated to the memory of the late Prof. Marija Kosec
In many cases, the conventional solid-state processing fails to provide ceramics of complex oxides
with sufficiently high compositional homogeneity. Mechanochemical processing, an alternative
approach often referred to as the “high-energy milling”, is a simple milling method that is capableto provide powders with superior homogeneity and sinterability. The aim of this contribution is toreview the role and benefits of mechanochemistry in the processing of ferroelectric oxides throughtwo known examples: (K,Na,Li)(Nb,Ta)O3 and BiFeO3. After revising the main processing issues
associated with these two oxides, we will show how key problems, such as achieving highhomogeneity and reducing the number of processing steps, are overcome by introducing themechanochemical approach. In addition, we will gain insight into the reaction mechanisms,
revealing the origins of the high reactivity of the mechanochemically processed powders.
One of the main issues in the processing of the Li- and Ta-modified (K,Na)NbO3 (KNLNT)
ceramics is achieving high compositional homogeneity, particularly at the B-site of the perovskite
ABO3 lattice. The reason lies in the low diffusivity of Nb5+ and Ta5+, which prevents complete
homogenization of the two cations in the solid solution during calcination and subsequent sintering.
In contrast to the thermally activated solid-state reaction, which is governed by diffusion processes,
the mechanochemical treatment of the initial powder mixture of alkaline carbonates and transitionmetal oxides is characterized by the formation of an amorphous carbonato complex. This phase,
which was identified by means of infrared spectroscopy analysis, consists of CO32– groups
coordinated to the Nb5+ and Ta5+ cations. The complex thus provides direct chemical binding
between the alkaline ions and transition-metal ions via the carbonate group. Through systematicstudies, we will show that this phase is largely responsible for the high level of chemical
homogeneity of the activated powder and, consequently, of the resulting KNLNT ceramics.
Despite being compositionally simpler than KNLNT, the synthesis of phase-pure BiFeO3 isextremely difficult. The persistence of the secondary phases, i.e., Bi25FeO39 and Bi2Fe4O9, in the
final ceramics is frequently reported in the literature and it is most probably associated with theparticular thermodynamics and reaction kinetics of this system. We recently developed a two-step
synthesis route for BiFeO3, involving mechanochemical activation of the Bi2O3–Fe2O3 powder
mixture, followed by reactive sintering. The resulting BiFeO3 ceramics were able to withstand highelectric fields, i.e., as high as 180 kV/cm, allowing us to pole the ceramics and study systematicallythe piezoelectric properties. Some of these results will be presented and discussed as well.

ISAF2-D1-2 _____________________________________________________________________________________________________________________

Influence of Ca/Zr Substitution on Grain Size Effect of
BaTiO3-Based Ceramics
Takuya Hoshina, Tsutomu Furuta, Takahiro Yamazaki, Hiroaki Takeda, Takaaki Tsurumi
Nano-Phononics Lab., Graduate School of Science and Engineering,Tokyo Institute of Technology, Meguro, Tokyo, Japan
Email: thoshina@ceram.titech.ac.jp
BaTiO3 is typical ferroelectrics with high permittivity and have been used as materials for dielectric
devices such as multilayered ceramic capacitors (MLCCs). In ferroelectrics, it is known thatdielectric permittivity depends on the grain size.116 This phenomenon is called the grain size effect,
which is a significant problem to development next-generation dielectric devices. BaTiO3-based
ceramics such as (Ba,Ca)TiO3 and Ba(Zr,Ti)O3 ceramics have been expected as materials for
MLCCs. However, the grain size effects of (Ba,Ca)TiO3 and Ba(Zr,Ti)O3 ceramics, including thesemechanisms, remain unclear. In this study, we investigated the influence of Ca/Zr substitution on
the grain size effect of BaTiO3-based ceramics.
Highly dense BaTiO3-based ceramics with micrometer- and nanometer-sized grains were fabricatedby a two-step sintering method and aerosol deposition (AD) method, respectively. The two-stepsintering is a promising technique for obtaining highly dense ceramics without significant grain
growth. The AD method is a unique technique that enables nanograined ceramic fabrication at room
temperature. Figure 1 shows the grain size dependence of dielectric permittivity of BaTiO3-based
ceramics.1,117 The permittivity of BaTiO3 ceramics increased with decreasing grain size when thegrain size was more than 1 µm, whereas it decreased when the grain size was below 1 µm. The
permittivity of Ba0.92Ca0.08TiO3 ceramics is much smaller than that of Ba0.92Ca0.08TiO3 ceramics at
micrometer-sized grains. In contrast, the permittivity of Ba0.92Ca0.08TiO3 ceramics is almost thesame as that of BaTiO3 ceramics at
nanometer-sized grains. The permittivityof the BaZrxTi1-xO3 ceramics markedly
decreased with decreasing grain size
below 3 µm. The permittivity of theBaZrxTi1-xO3
nanograined
ceramics
decreased with increasing Zr content andwas much smaller than the permittivity of
the BaTiO3 nanograined ceramics. These
results indicated that the BaZrxTi1-xO3
ceramics were more susceptible to thegrain size effect than the pure BaTiO3
ceramics.

116

Fig. 35: Grain size dependence of permittivity of BaTiO3based ceramics.

T. Hoshina, “Size effect of barium titanate: fine particles and ceramics”, J. Ceram. Soc. Jpn., vol. 121, p. 156-161,
2013.
117

T. Hoshina, T. Furuta, T. Yamazaki, H. Takeda, and T. Tsurumi, “Grain Size Effect on Dielectric Properties ofBa(Zr,Ti)O3 Ceramics”, Jpn. J. Appl. Phys., vol. 51, 09LC04, 2012.

ISAF2-D1-3 _____________________________________________________________________________________________________________________

Processing of Bi(Zn1/2Ti1/2)O3-BaTiO3 dielectrics for reliablehigh field operation
Geoff L. Brennecka1, Harlan J. Brown-Shaklee1, Natthaphon Raengthon2, Mia A. Blea1, David I.
Shahin3, David P. Cann2, Wayne Huebner3
1

Electronic, Optical, and Nanostructured Materials, Sandia National Laboratories, Albuquerque,
NM, USA2
Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, OR,USA
3
Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO,
USA
Email: glbrenn@sandia.gov
Weakly-coupled relaxor systems based on modifications of BaTiO3 with Bi-based perovskites areof interest for a variety of capacitor applications because of their ability to maintain relatively large
permittivity, low loss tangents, and high resistivity values under large electric fields and/or atelevated temperatures118. Our work focuses on relatively large (>100nF) capacitors for high voltage(>1kV) operation (Figure 1) to address the need for reliable high-operating-temperature capacitors
for emerging power electronics systems based on wide bandgap semiconductors. We report here on
effects of compositional variation and processing parameters on microstructure as well as various
electrical parameters of materials in the Bi(Zn1/2Ti1/2)O3 - BaTiO3 system.
Bi-based additives assist in densification at reasonable temperatures but also greatly complicate
cofiring of these systems with desired electrodes. In addition to the volatility of Bi during sintering,
Bi2O3 is unstable in contact with metallic Ni, offers a vanishingly-small thermodynamic stability
window with regard to metallic Cu, and tends to alloy with Pt and Pd at temperatures commonlyused for densification of free-standing
ceramic pellets. Nevertheless, we show herethat BZT-BT MLCCs can be successfully
cofired with both Pt and Ag-Pd electrodes
and can provide reliable performance underhigh field and high operating temperatures.
We also discuss the effects of various
processing
parameters
includingcontaminants,
sinteringconditions,Fig. 36: Bi(Zn Ti1/2)O3-BaTiO3-based MLCC (center)electrode interactions, and liquid phase shown with two1/2similar
polymer film capacitors (left andright) of the same capacitance value (220nF) at rated
operating voltage for ambient conditions (shown below
each part). The MLCC also operates at temperatures
118
N. Raengthon, T. Sebastian, D. Cumming, I.M. Reaney
and D.P. Cann, “BaTiO3-Bi(Zn1/2Ti1/2)O3-BiScO3 Ceramics>200°Cfor High-Temperature Capacitor Applications”, J. Am. Ceram. Soc., vol. 95, p. 3554-3561, 2012.

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly
owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security
Administration under contract DE-AC04-94AL85000. This work was supported by the Department of Energy’s Officeof Electricity Delivery and Energy Reliability, Energy Storage Systems program managed by Dr. Imre Gyuk.

additives, on permittivity, resistivity and degradation mechanisms.

ISAF2-D1-4 _____________________________________________________________________________________________________________________

Electromechanical Properties of Hard
Lead-free Bi0.5Na0.5TiO3-based Ceramics
E. Taghaddos, M. Hejazi, and A. Safari
Glenn Howatt Electroceramics Laboratory
Department of Materials Science and Engineering, Rutgers University
607 Taylor Rd, Piscataway, NJ 08854

It has been previously shown that in a ternary system of x[Bi0.5Na0.5TiO3]-y[Bi0.5K0.5TiO3]-(1-x-y)[Bi0.5Li0.5TiO3], the highest mechanical quality factor (Qm) is obtained at a composition with x andy values of 0.88 and 0.08, respectively. In this work, processing and electrocmechanical propertiesof Mn-doped 0.88[Bi0.5Na0.5TiO3]-0.08[Bi0.5K0.5TiO3]-0.04[Bi0.5Li0.5TiO3] ceramics prepared bymixed oxide route have been comprehensively studied. Different amount of Mn (0.01, 0.014,
0.015, 0.01625, 0.0175, 0.02, and 0.022) was added to the ceramics either in form of a dopant (Bsite substitution) or as an additive after calcination. Pressed samples were sintered at different
temperatures (1075-1150 oC) and time. It was found that Mn-addition did not exhibit any hardening
effect and in fact led to an increase in the dielectric loss. On the other hand, Qm was remarkably
increased by Mn-doping in the B-site. Mn-doping was also resulted in decreasing in planar coupling
coefficient, dielectric constant, and dielectric loss which are common effects in hard ferroelectrics
doped with an acceptor. The Qm, d33, kp, εr and tanδ values for 0.015 Mn doped sample were 950,
85 pC/N, 0.218, 310, and 0.009, respectively. Sintering temperature inceramics were slightly lower than undoped samples..

Mn doped

BNKLTISAF2-D1-5 _____________________________________________________________________________________________________________________

Poling below Coercive Field for Large Piezoelectricity
Xiaoli Tan, Hanzheng Guo, Cheng Ma, Xiaoming Liu
Department of Materials Science and Engineering, Iowa State University, Ames, Iowa/USA
Email: xtan@iastate.edu
Piezoelectric materials are key to many important technologies, including energy harvesting, noise
cancellation, and minimally invasive surgery. The dominant piezoelectric materials in industry arepolycrystalline ferroelectrics, which must be poled by electric fields to exhibit piezoelectricity.
During electrical poling, the originally randomly oriented polarizations are aligned by the polingfield, forming the macroscopic non-centrosymmetry that is required for piezoelectricity. Therefore,
it is commonly believed that poling fields have to be much greater than the coercive field EC, whichcharacterizes the difficulty of polarization reversal in ferroelectrics. Such an empirical rule is basedon and supported by numerous experimental observations on all the widely studied piezoelectrics sofar. Poling fields below or around EC only yield very small piezoelectric coefficient d33 values thatare close to zero.
In the present work, we report that well-developed piezoelectric properties are measured in certain
lead-free (1-x)(Bi1/2Na1/2)TiO3–xBaTiO3 compositions even when they are poled at fields
significantly below their measured coercive fields. Prior to poling, these compositions are in themorphotropic phase boundary region and display a relaxor behavior with the ferrielectric P4bm
structure. Electric field in-situ transmission electron microscopy experiments reveal that thisunusual behavior is originated from the poling of the non-ergodic relaxor ferrielectric phase where
P4bm nanodomains irreversibly coalesce and form extremely thin lamellar domains. Similar
behavior is also confirmed in a lead-containing relaxor ferroelectric (Pb0.92La0.08)(Zr0.65Ti0.35)O3.

Domain engineering
CLUB B
Tuesday, July 23 2013, 10:30 am - 12:00 pm
Chair:To Be Announced

ISAF1-D2-1 _____________________________________________________________________________________________________________________

Investigation of intrinsic domains in PbTiO3 ultrathin films: from nanodots to nanostripes
Céline Lichtensteiger, Pavlo Zubko and Jean-Marc Triscone
DPMC – University of Geneva, 24 Quai Ernest Ansermet, CH – 1211 Genève 4
Email: celine.lichtensteiger@unige.ch

In ferroelectric ultrathin films, the depolarization field arising from bound charges on the surface ofthe film and at the interface with the substrate can be partially screened by free charges frommetallic electrodes, ions from the atmosphere, or mobile charges from within the semiconducting
ferroelectric itself. Even in structurally perfect metallic electrodes, the screening charges will spreadover a small but finite length, giving rise to a nonzero effective screening length that will
dramatically alter the properties of an ultrathin film. In the absence of sufficient free charges, aferroelectric has several other ways of minimizing its energy while preserving its polar state, e.g.,
by forming domains of opposite polarization, or rotating the polarization into the plane of the thin
ferroelectric slab 119.
Using piezo-force microscopy (PFM), we investigate the intrinsic nanodomain structure of PbTiO3
ultrathin films at room temperature.
By changing the degree of screening, the domain structure can be modified or even suppressed infavour of a uniform monodomain state.
Focusing on the effect of film thickness, we observe the evolution of the size and shape of the domains fromlarge nanodots to small stripes as the PbTiO 3 films thickness decreases.

119

Ferroelectricity in ultrathin-film capacitors, C. Lichtensteiger et al, Ch. 12 in Oxide Ultrathin Films, Science andTechnology, Wiley (2011) (arXiv:1208.5309v1 [cond-mat.mtrl-sci])

ISAF1-D2-2 _____________________________________________________________________________________________________________________

Ferroelectric Domain Wall Injection via Electric Field
Engineering
J. R. Whyte1, R. G. P. McQuaid1, P. Sharma2, C. Canalias3, J. F. Scott4, A. Gruverman2 and J. M.
Gregg1
1

School of Mathematics and Physics, Queen’s University Belfast, Belfast, United Kingdom

2

Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska, USA
3

Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
4

Department of Physics, Cavendish Laboratory, Cambridge, England, UK
Email: jwhyte05@qub.ac.uk

The

discoveryofenhancedconductivity in ferroelectric domain
walls has prompted a number of ideas
for new electronic devices, such astransistors and memristors, which
operate through the existence orotherwiseofconducting

domainwall-based

channels

betweenelectrodes. For such devices to work,

Fig. 37: (a) Electric field model of KTP lamella under thecomplete control over where domain application of 100 V with field hotspots positioned at insidewalls

they images show the appearance of a new domain nucleating from one

subsequently move is crucial120.

of the hot-spots post application of 60 V, implying that the
production of field hotspots can control the exact location of
how reverse domain nucleation.

we

and

vertices of triangular holes. (b) Amplitude (left) and phase (right)

how

Here,

nucleatedemonstrateengineering of the local electric field, using focused ion beam-milled defects, can be used to allow
site-specific domain wall injection in thin single crystal lamellae of the uniaxial ferroelectric
KTiOPO4 (KTP). We also show how designed variations in local field can dictate subsequentdomain wall mobility. Defect-related field engineering is thus demonstrated as a new paradigm fordomain wall control as part of a journey towards realizing domain wall nanoelectronic devices.

120

H. Béa, P. Paruch, “Multiferroics: A way forward along domain walls”, Nature Mater., vol 8, p. 168–169, 2009.

ISAF1-D2-3 _____________________________________________________________________________________________________________________

Breathing mode of domain wall motion and spatial energy
landscapes in ferroelectric BiFeO3 films
Jong-Gul Yoon1, Tae Heon Kim2, S. H. Baek3, S. M. Yang2, J.-S. Chung4, C. B. Eom3, and T. W.
Noh2
1

Department of Physics, University of Suwon, Gyunggi-do 445-743, Korea
2
IBS-CFI-CES, Seoul National University, Seoul 151-747, Korea
3
Department of Materials Science and Engineering, University of Wisconsin, Madison, WI 53706,
USA
4
Department of Physics, Soongsil University, Seoul 156-743, Republic of Korea
Email: jgyoon@suwon.ac.kr

We investigated a breathing mode of ferroelectric domain wall motion in an epitaxial BiFeO3 filmgrown on a vicinal SrTiO3 (001) substrate by monitoring ferroelectric domain evolution undersuccessive pulse fields with piezoresponse force microscopy. An anisotropic domain growth, whichshould be caused by a structurally-driven symmetry breaking,121 resulted in the breathing mode ofsideways domain wall motion withthe alternative application of negativeand positive electric pulse fields. The
domain-shape-preserving breathingmode of domain wall motion
indicated that the domain shapeshould be governed by the spatial
energy landscapes, which would bedetermined by the corresponding
domain wall energies as well as the
distribution of defects acting as
pinning sites. With the theoreticalresults of domain wall energies in
BiFeO3, we showed that 109 and 180°
domain walls critically affect thepolarity dependence of various
dynamics properties, such as domain Fig. 38: (a) Pulse sequences for observing breathing modeshape, nucleation sites, and domain of domain wall motion. [(b) and (c)] Successive out-ofwall velocity. The domain-shape- plane PFM phase images of the domain evolution induced
preserving breathing mode can be by the pulse fields. ⊙ and ⓧ represent the direction of the
exploited for ferroelectric domain applied upward and downward electric field, respectively.
wall motion devices.
The bright and dark regions represent ferroelectric domains
with upward and downward polarization, respectively.
121

T. H. Kim et al,, “Electric-field-controlled directional motion of ferroelectric domain walls in multiferroic BiFeO3
films”, Appl. Phys. Lett. Vol. 95, p. 262902, 2009.

ISAF1-D2-4 _____________________________________________________________________________________________________________________

Multiscaling analysis and thermal quench effects of domain
walls in epitaxial BiFeO3 thin films
Benedikt Ziegler1, Ingrid Infante2, Stephane Fusil2, Manuel Bibes2 and Patrycja Paruch1
1
MaNEP-DPMC, University of Geneva, Geneva, Switzerland
2
Unité Mixte de Physique CNRS/Thales, Palaiseau Cedex, France
Email: benedikt.ziegler@unige.ch
The coexistence of ferroelectric and antiferromagnetic ordering at room temperature have led tointense research on multiferroic BiFeO3. In addition, the recent discoveries of interesting new
phenomena like conducting ferroelectric domain walls122 make it a promising candidate fornanoelectronic applications123.
Here, we present our study of the microscopic behavior of such domain walls within the broader
framework of elastic disordered systems, using vertical and lateral piezoresponse force microscopy
to study the roughness of artificially written and intrinsic domain walls in ambient conditions andunder thermal cycling. A multiscaling analysis of the domain walls can be used to discriminate
between different kinds of disorder. While this analysis was previously applied to artificially written
ferroelectric domain walls124, we use it here to study intrinsic stripe-like 71° multiferroic domain
walls, which are potentially better equilibrated and have a richer internal structure due to strain andpotentially also electromagnetic coupling. From these studies we extract a characteristic lengthscale, below which the domain walls show a mono-affine scaling, usually an indication of weakcollective pinning in random disorder. However, unlike for the individual artificially written walls,
in this case long-range interactions between the domain walls appear to dominate the effective
elastic behavior. The domain walls show higher roughening than purely artificially written
ferroelectric domain walls. Independently, we also present the evolution of domain wall roughness
with thermal cycling125 in artificially written walls in BiFeO3.

122

Seidel, J., et al., Nature Mater. 8, 229, 2009

123

Catalan, G., et al., Rev. Mod. Phys. 84, 119-156, 2012124

Guyonnet, J., et al., Phys. Rev. Lett. 109, 147601, 2012

125

Paruch, P., et al., Phys. Rev. B 85, 214115, 2012

ISAF1-D2-5 _____________________________________________________________________________________________________________________

Nanodomain Structuring of Uniaxial Ferroelectrics.
Achievements in Nanodomain Engineering
Shur Vladimir 1,2
1

Ferroelectric Laboratory, Ural Federal University, Ekaterinburg, Russia
2
Labfer Ltd., Ekaterinburg, Russia
Email: vladimir.shur@usu.ru

Nanodomain engineering is the important modern target of the ferroelectric science and technology.
The production of ferroelectric crystals with periodical tailored stable domain structure used for
spatial modulation of their electro-optic, nonlinear optical and piezoelectric properties allow to
manufacture various devices with upgraded performance. The fabrication of sub-micron-pitch
quasi-regular domain gratings and engineered structures with nanoscale precision for photonic
applications needs the deeper research of domain formation with submicron spatial resolution.
The set of modern high-resolution methods including piezoresponse force microscopy, scanningelectron microscopy and confocal Raman microscopy applied for domain study in nanoscale has
allowed to reveal the important role of nanodomain kinetics and to investigate the evolution of selfassembled nanodomain structures. The resent important achievements in studying of thenanodomain structure evolution obtained in highly non-equilibrium switching conditions realizedby various methods and characterized by ineffective screening of depolarization fields has beenreviewed. Several new effects leading to formation of the quasi-regular dendrite nanodomain
structures has been demonstrated.
The crystals of lithium niobate and lithium tantalate family were studied both as the model
ferroelectrics and as the most important for application nonlinear optical materials. Their simple
domain structure and ability to change the bulk screening rate in wide range by heating allows torealize the nanodomain structuring.
The nanodomain kinetics has been studied in the samples with the surface layer modified by proton
exchange and during switching by pyroelectric field during cooling after multiply pulse laser
heating. The types of nanoscale domain structures and original scenarios of their evolutions havebeen singled out. The unique information about evolution of the nanodomain structures has been
revealed by analysis of the domain images at different depth in the bulk obtained by scanning laser
confocal Raman microscopy. The stable self-assembled stripe domain structures with periods about
20 nm has been produced.
The obtained knowledge opens the new approach to the nanodomain engineering. The highefficient crystals for laser light frequency conversion in spectral range from 0.4 to 4 m have been
manufactured.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has
been used. The research was made possible in part by RFBR (Grants 13-02-01391-а, 12-02-31377,
11-02-91066-CNRS-а), by Ministry of Education and Science (Сontract 14.513.12.0006).

High Temperature Piezoelectrics
CLUB C
Tuesday, July 23 2013, 10:30 am - 12:00 pm
Chair:David Cann
Oregon State University

ISAF1-D3-1 _____________________________________________________________________________________________________________________High Temperature Piezoelectric Crystals: Recent
Developments and Application Specifications
Shujun Zhang1,2, Fapeng Yu3, Thomas R. Shrout2
1

2

Electronic Materials Research Laboratory, Xi’an Jiaotong University, Xi’an, China
Materials Research Institute, Pennsylvania State University, University Park, PA, US
3
Institute of Crystal Materials, Shandong University, Ji’nan, China
Email: shujunzhang@gmail.com

Piezoelectric materials that can function at high temperatures without failure are desired forstructural health monitoring and/or nondestructive evaluation of the next generation turbines, more
efficient jet engines, electrical and nuclear power plants. The operational temperature range of thesmart transducers is limited by the sensing capability of the piezoelectric material at elevatedtemperatures, increased conductivity and mechanical attenuation, variation of the piezoelectric
properties with temperature. This paper discusses properties relevant to sensing applications,
including ferroelectric materials and non-ferroelectric piezoelectric crystals.
Recent developments in advanced piezoelectrics are highlighted in the figure, showing
piezoelectric activity versus maximum usage temperature range for various piezoelectric materials.
The relaxor-PT ferroelectric crystals with perovskite structure were found to possess the highest
piezoelectric properties, with d33 values being on the order of >2000pC/N, however, their usage
temperature range is limited by the low
ferroelectric phase transition TRTs126. Perovskite
polycrystalline ceramics, including PMNT, PZTand BSPT, have sensitivities in the range of
200pC/N to 900pC/N, with a usage temperature
range of 100-400oC, restricted by thermally
activated aging behavior at temperatures far below
their TCs. Ferroelectric materials with the tungsten
bronze and Aurivillius structures possess medium
piezoelectric properties, ranging from 10pC/N to
100pC/N, with usage temperatures up to 550oC,
limited by TC or low electrical resistivity atelevated temperatures. It should be noted thatthough LN crystals possess a TC of 1150oC, their
low resistivities and oxygen loss at elevatedtemperature restrict applications to < 600oC.

126

S. Zhang and F. Li, “High performance ferroelectric relaxor-PT single crystals: status and perspective,” J. Appl.
Phys., Vol.111, 031301, 2012.

Generally, nonferroelectric piezoelectric single crystals possess low sensitivity, falling in the rangeof 1-20pC/N, however, their ultralow mechanical and dielectric losses, and high electricalresistivities, make them ideal candidates for ultra-high temperature sensing applications127.

127

S. Zhang and F. Yu, “Piezoelectric materials for high temperature sensors,” J. Am. Ceram. Soc., Vol.94, pp.31533170, 2011.

ISAF1-D3-2 _____________________________________________________________________________________________________________________High Temperature Behaviors of Piezoelectric Sorosilicate
Single Crystals
H. Takeda1, M. Hagiwara1, H. Noguchi1, T. Hoshina1, N. Kodama2 and T. Tsurumi1
1
2

Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8550, Japan.
Akita University, 1-1 Tegata-gakuencho, Akita 010-8502, Japan
E-mail: htakeda@ceram.titech.ac.jp

High temperature piezoelectric materials are highly demanded for gas sensors, combustion pressure
sensors (CPS) and gas injectors directly placed in the cylinder part of engines. For the CPS use, thematerial need possess a low temperature dependence of the piezoelectric properties and a highelectric resisitvity at high temperature. Currently, there are four candidates of piezoelectricmaterials such as gallium phosphate (GaPO4), langasite (La3Ga5SiO14) family, rare-earth calcium
oxoborate (YCa4O(BO3)3), and aluminum nitride (AlN). Among of them, the most promising
candidates are langasite type single crystals
because the crystals with large size can be
Temperature [oC]
900
700
600
500
400
300
synthesized by melt growth technique. However,10
these crystals need still improvement of electric
10
Sorosilicate
resisitvity. In this study, we have demonstrated theLTGA
10possibility of sorosilicate-type single crystal for
YCa4O(BO3)3
LTG
high temperature use. Material constants of the10
LGS
crystal were determined at the driving temperature
10o(@400 C). Resistivity measurement was also
10
conducted up to 700oC. The sorosilicate crystal
showed ten times higher resistivity than those of
10
langasite family as shown in Fig. 1. We have
10
0.8
1.0
1.2
1.4
1.6
1.8
constructed measurement system of direct
1000/T [K-1]
piezoelectric effect at high temperature andcharacterized the crystals under pseudo Fig. 1. Temperature dependence of resistivity of
combustion environment in the engine cylinder. sorosilicate-type crystal and langasite family
Output charge against applied stress was properly crystals (LTGA: Al-doped La3Ta0.5Ga5.5O14, LTG:
detected at 400○C. The sorosilicate-type crystal La3Ta0.5Ga5.5O14, LGS: La3Ga5SiO14). The inlet is ashowedbetterperformancethanother photograph of the sorosilicate-type crystal grown by
Czochralski technique.
piezoelectric materials.
12

Resistivty [Ohm･cm]

11

10

9

8

7

6

5

ISAF1-D3-3 _____________________________________________________________________________________________________________________

Bi(B’B”)O3 – PT based High Temperature Piezoelectrics
Ben Kowalski1, Alp Sehirlioglu1
1

Materials Science and Engineering, Case Western Reserve University, Cleveland, OH/USA
Email: bak121@case.edu

High temperature piezoelectrics are sought after for ultrasonic drilling on the surface of Venus,
dampening of turbine blades in hot regions, and energy harvesting in a thermoacoustic engine, etc.
Previous studies by Grinberg and Eitel have predicted Curie temperatures (Tc) greater than that ofPb(Zr,Ti)O3 (PZT) through solid solutions of Bi(B’B”)O3 with PbTiO3(PT).128,129 In this work,
doping for the B-site cations is explored through combination of the ternary (1-x-y)BiScO3–(x)Bi(Zn0.5,Zr0.5)O3–(y)PbTiO3 (BS-BZZ-PT) with In, Mn, Sb, Sn, Ga, and Sm. These systems arebeing investigated via weak and high field studies to establish dielectric and electromechanicalproperties as a function of temperature, frequency, and electric field.

Room temperature examples of hysteresis/strain loops are shown in Fig. 1 for unmodified BZZ2
(37.5BS-2.5BZZ-60PT) and two modified compositions, BZZ2-1PMn (1Mn for 1Ti) and SIZZD(30BS-5BZZ-5BI-60PT). Planar coupling factor vs. temperature is compared in Fig. 2 for the threeprevious compositions as well as two commercial PZT’s. The Bi-based compositions have superiortemperature stability for kp as well as other properties. Aliovalent doping of Mn for Ti (1PMn)increases the mechanical quality factor (Qm), decreases the tanδ with no loss in Tc, but a drop in kp
does occur. Trading out 5BS for 5BI (SIZZD) increases kp, increases the d33 from 430 to 630 pm/V,
but reduces the Tc by ~20°C. Doping schemes will be shown to design piezoelectrics for different
applications by modifying kp, εr, Qm, tanδ, and d33.

128
129

J. Appl. Phys. 98, (2005)
Jpn. J. Appl. Phys. Vol. 40 (2001)

ISAF1-D3-4 _____________________________________________________________________________________________________________________

Pb(Yb1/2Nb1/2)O3-PbTiO3, structure-property relation in a hightemperature piezoelectric materialCharlotte Cochard1,2, Christine Bogicevic1, Xavier Bril1, Nicolas Guiblin1, Florence
Porcher3,Orland Guedes 2, Pierre-Eymeric Janolin1
1

Laboratoire SPMS , UMR CNRS-École Centrale Paris, Châtenay-Malabry, France
2
Schlumberger, Clamart, France
3
Laboratoire LLB, CEA, Saclay, France
Email: Charlotte.Cochard@ecp.fr

Piezoelectricity has attracted a considerable amount of work due to the variety of possible
applications such as accelerometers, gyroscopes or transducers. Solid solutions of relaxors andclassical ferroelectrics are know to exhibit enhanced piezoelectric properties close to themorphotropic phase boundary (MPB) compared to the pure materials counterpart. Therefore,materials such as Pb(Mg1/3Nb2/3)O3-PbTiO3 or Pb(Zn1/3Nb2/3)O3-PbTiO3 have been extensively
studied over the last 50 years. On the contrary, Pb(Yb1/2Nb1/2)O3-PbTiO3 (PYN-PT) which is longknown to have good piezoelectric properties (d33=510pC/N) and a relatively high Curie temperature(~370°C at the MPB) has not been examined so extensively probably because of the scarcity ofsingle crystals
In this work, we will present experimental data obtained on PYN-PT of different compositions
close to the MPB. These data were obtained by X-ray diffraction, neutron scattering as well as
dielectric and piezoelectric measurement as a function of temperature, enabling a clearer picture of
the structure-property relation around the MPB to emerge in this material of crucial importance forhigh-temperature applications.

ISAF1-D3-5 _____________________________________________________________________________________________________________________

Piezoceramic Materials for High-Temperature & High-Pressure
Applications in Oilfield Exploration & Production
Kenneth Liang1, Wanda Wolny2, Dragan Damjanovic3, Torsten Bove2
1

Schlumberger-Doll Research, Cambridge, MA, USA2
Meggitt A/S, Kvistgaard, Denmark3
Institute of Materials, EFPL, Lausanne, Switzerland
Email: kliang@slb.com

Ultrasonic measurements play important roles in many oilfield services applications. With oil wells
reaching ever increasing depths, the operating environment is characterized by high temperatureand high pressure (175˚C, 20,000psi and beyond). Ultrasonic transducers typically operate into aliquid-filled borehole. Lead metaniobate, mainly due to its low acoustic impedance and despite its
low kt, is used where both efficiency and bandwidth are required. There is ongoing effort though toseek equivalent and better substitute materials. This work is a continuation of a previous study
carried out on Pz31 and Pz36, two PZT-based materials developed by Meggitt A/S with engineered
porosity130. While these materials are well-behaved with temperature, both tend to depole whensubjected to 15,000psi, with Pz31 being more susceptible to depoling than Pz36. The polarization
can be restored by repoling afterwards, indicating that depoling is due only to rearrangement ofpolarization within samples and not mechanical failure. The depoling mechanism is not understoodand the difference in vulnerability to static pressure appears to be inconsistent with the relative
degree of hardness of, and the rhombohedral and tetragonal structures of Pz31 and Pz36
respectively. To develop insight, we carried out identical temperature and pressure tests on the
fully densified versions of Pz31 and Pz36, Pz24 and Pz26 respectively. The experimental setup isdescribed and the results and analyses are given.
A bismuth titanate based material, Pz46, has also been studied for its suitability under extreme
conditions. It exhibits kt ~ 0.2, slightly higher acoustic impedance than lead metaniobate, Curie
temperature in excess of 600˚C, and is highly resistant to shock. The material has been temperature
cycled up to 200˚C with no degradation and results of pressure cycling to assess its field worthinesswill be reported and discussed.

130

Bove, Liang, Wolny, “Experimental Study of Temperature & Pressure Effects on High-Porosity PZT Materials,”IEEE Ultrasonics Symposium Proceedings, Dresden, 2012

Lead-free ceramics: E-field Effects
CLUB A
Tuesday, July 23 2013, 02:00 pm - 03:30 pm
Chair:

Xiaoli Tan
Iowa State University

ISAF3-E1-1 _____________________________________________________________________________________________________________________

In situ diffraction reveals the dependence of BaTiO3 grain sizeon domain wall motion and relation to macroscopic properties
Jacob L. Jones1, Dipankar Ghosh,1 Akito Sakata,1 Jared Carter,1 Hyuksu Han,1 Juan C. Nino,1 andPam A. Thomas2
1

Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611,
USA
2
Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
Email: jjones@mse.ufl.edu

It is now widely accepted that polycrystalline barium titanate (BaTiO3) exhibits maximum room
temperature relative permittivity (εr) at a grain size of approximately 1-2 µm and εr decreases below
and above this grain size. Some limited studies have also shown analogous behavior of thepiezoelectric coefficients, d33 or d31, with grain size. Two widely accepted theories attribute thisbehavior to either internal residual stress or non-180° domain wall motion, though a direct
measurement of the exact origin of such grain size effects has, to date, elucidated researchers.
Using an in situ high-energy X-ray diffraction (XRD) technique in transmission mode during
application of high external electric fields, we show conclusive and direct evidence that 90° domain
wall motion in BaTiO3 is present under high electric fields across the grain size range 0.2 μm to 3.5µm and, most notably, is maximum at a grain size of approximately 2 μm. Measurements of εr andd33 in these same samples show that the properties also peak at 2 μm (Figure 1).
X-ray measurement of the unit cell volume and spontaneous lattice strain also indicates that thedegree of residual internal stress due to changing domain wall density is measurable though small.
The current investigation thus conclusively attributes 90° domain wall motion to the grain size
dependence of BaTiO3 ceramics in the 0.2-3.5 μm range.

Fig. 39: Relative permittivity and longitudinalpiezoelectric coefficient measurements of thesamples synthesized for the present work.

ISAF3-E1-2 _____________________________________________________________________________________________________________________

High-speed data capture of the electric field induced phasetransition in potassium sodium bismuth titanate
Tim P. Comyn1, Andrew J. Bell1, Annette Kleppe2
12Institute for Materials Research, University of Leeds, Leeds, UK
Diamond Light Source, Harwell Science Campus, Didcot, Oxfordshire, UK
Email: t.p.comyn@leeds.ac.uk

The lead free system KNBT (xK1/2Bi1/2TiO3-(1-x)Na1/2Bi1/2TiO3) exhibits an electric field induced
phase transition from rhombohedral to mixed phase rhombohedral and tetragonal, for x=0.2, asconfirmed using in-situ synchrotron experiments. Here, we track the phase transition at high speed,using a state of the art Pilatus x-ray detector. Strobing has been used by other groups to track
ferroelectric materials driven around major and minor hysteresis loops, using synchrotron andneutron radiation, but such techniques are not appropriate here. The phase transition which occurs
in KNBT during poling is irreversible, except by heating to above 400 0C.
Data collected at 100 Hz shows that an electric field induced strain precedes the phase transition.
The detector was synchronized with the electric drive field. The complexities of the experiment, andfurther improvements are discussed.

ISAF3-E1-3 _____________________________________________________________________________________________________________________

Effect of Applied Field Direction in {001}pc Oriented
Bi0.5Na0.5TiO3-7BaTiO3-2K0.5Na0.5NbO3 Bulk CeramicsaChris M. Fancher, aJohn E. Blendell, and a,bKeith J. Bowman 

b) Mechanical, Materials & Aerospace Engineering, Illinois Institute ofTechnology, Chicago, Illinois 60616, USA
The high strain response of the Bi0.5Na0.5TiO3-yBaTiO3-xK0.5Na0.5NbO3 system has been attributed
to a reversible electric-field-induced phase transformation from a pseudocubic to a distorted polarstructure. A recent in situ experiment has reported BNT-6BT-2KNN to transform from anundistorted tetragonal into a phase mixture of distorted rhombohedral and tetragonal phases. In thiswork, the effect that crystallographic texture and texture symmetry have on the field-induced phasetransformation of BNT-7BT-2KNN bulk ceramics was investigated. Bulk BNT-7BT-2KNN
ceramics with a 8.6 multiples of a random distribution (MRD) {001}pc fiber texture were preparedusing the tape-casting method with a 5wt% template fraction. Texturing improved the high fieldstrain response of BNT-7BT-2KNN by 47%. To understand the origin of this improvement, theeffect texture symmetry has on the strain response was investigated by applying an electric fieldparallel or perpendicular to the {001}pc fiber texture axis. Applying the electric field perpendicular
to the fiber axis resulted in a high field strain response that was 16% lower compared to the strain
response for a field applied along the fiber axis. Field direction did not affect the volume expansion
during electric cycling; suggesting the field-induced phase transformation is independent of theapplied field direction. In situ diffraction showed that field direction does not effect the induced
phase formation; however, field direction did affect the ferroelastic texture and electric fieldrequired to induce the polar phase.

ISAF3-E1-4 _____________________________________________________________________________________________________________________

Electric Field-Induced Polarization and Strain in 94(Bi1/2Na1/2)TiO30.06BaTiO3 Under Uniaxial Stress
Robert Dittmer1, Kyle G. Webber1, Emil Aulbach1, Wook Jo1, Xiaoli Tan2, and Jürgen Rödel1
1
Institute of Materials Science, Technische Universität Darmstadt, Darmstadt, Germany
2
Department of Materials Science and Engineering, Iowa State University, Ames, IA, USA
Email: dittmer@ceramics.tu-darmstadt.de
Solid solutions based on Bi1/2Na1/2TiO3 (BNT) are capable of producing large strains that rival PZTat high electric fields. In application an actuator has to produce large displacements against an
external mechanical load. Blocking stress measurements demonstrated that 0.94Bi1/2Na1/2TiO30.06BaTiO3 (BNT-6BT) can provide a large maximum stress B of 102 MPa at 125 °C. The
addition of 2 mol% K0.5Na0.5NbO3 affords a large B of 124 MPa even at room temperature.
However, the effect of stress on the unipolar large-signal behavior remains unknown. In this study
we present for the first time the complex field-, stress- and temperature-dependent large-signal
properties of a lead-free piezoceramic. Polarization and strain hystereses have been obtained for themodel material BNT-6BT during unipolar electric field loading from room temperature to 150 °C
under uniaxial compressive stress up to 446 MPa. For low temperatures the maximum strain peaks
at a certain stress due to enhanced non-180° domain switching. At 125 °C a large strain with alarge-signal piezoelectric coefficient d33* of 884 pm·V-1 is observed, which decreases upon theapplication of stress. This behavior is rationalized with a change in the primary strain mechanism
from domain switching at low temperatures to a reversible electric field-induced transition from anergodic relaxor state to a long-range order at high temperatures (see Figure). In addition, the energy
terms for the output mechanical work and the charged electrical energy density are analyzed andused to define a large-signal efficiency.
Strain normalized to room temperaturestrain at zero-field as a function of stress for
BNT-6BT.

ISAF3-E1-5 _____________________________________________________________________________________________________________________

Exploration of Microscopic Mechanisms of the Polarization
Switching in Lead-free BZT-xBCT Ferroelectrics
Sergey Zhukov, Yuri Genenko, Matias Acosta, Heide Humburg, Wook Jo and Heinz von Seggern
1

Institut für Materialwissenschaft, TU Darmstadt, Darmstadt, Germany
Email: zhukov@e-mat.tu-darmstadt.de

Nowadays lead-free ferroelectric materials are receiving considerable attention as replacement forthe market dominating, toxic lead-containing PZT ceramics. Recently discovered Ba(Zr0.2Ti 0.8)O3x(Ba0.7Ca0.3)TiO3 compositions show piezoelectric properties comparable to that of PZT.131 Similar
to PZT, BZT-xBCT possesses a morphotropic phase boundary (MPB) where piezoelectric
properties peak. At room temperature this boundary is at x = 50% between the rhombohedral BZT
and the tetragonal BCT.
In the current research the polarization switching process in different BZT-xBCT compositions(0.3  x  0.6) has been studied over a broad time domain covering range from 1μs to 100s. For allcompositions investigated the temporal evolution of the switched polarization exhibits a rather
complex shape which cannot be rationalized by the classical switching concept of nucleation andgrow of reversed domains known also as the Kolmogorov-Avrami-Ishibashi (KAI) model. Unlike
the KAI approach, the recently developed Inhomogeneous Field Mechanism (IFM) model132,133
provides an adequate fit to the experimental results. Moreover, the experimentally obtained
dependencies of the switching time on the electric field strongly suggest the existence of two
distinct switching mechanisms in different field regions. The microscopic origin of bothmechanisms as well as the evolution of their parameters with composition, microstructure andtemperature will be discussed.

131

W.F. Liu, X.B. Ren, “Large Piezoelectric Effect in Pb-Free Ceramics”, Phys. Rev. Lett., 103, 257602, 2009.

132

S. Zhukov, Y. A. Genenko, O. Hirsch, J. Glaum, T. Granzow, H. von Seggern, “Dynamics of polarization reversal invirgin and fatigued ferroelectric ceramics by inhomogeneous field mechanism”, Phys. Rev. B, 82, 014109, 2010.
133

Y. A. Genenko, S. Zhukov, S.V. Yampolskii, J. Schütrumpf, R. Dittmer, W. Jo, H. Kungl , M.J. Hoffmann, H. vonSeggern, “Universal Polarization Switching Behavior of Disordered Ferroelectrics”, Adv. Funct. Mater., 22, 2058-2066,
2012.

ISAF3-E1-6 _____________________________________________________________________________________________________________________

Electric Field Effects on Domain Processes and Properties in
Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 Piezoceramics
Matthias C. Ehmke1, John E. Blendell1, Keith J. Bowman1,2
12Materials Engineering, Purdue University, West Lafayette, IN 47907, USA
Mechanical, Materials & Aerospace Engineering, Illinois Institute of Technology, Chicago, IL
60616, USA
Email: ehmke@purdue.edu

The lead-free Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 (BZT-BCT) system has been demonstrated to show
attractive piezoelectric performance at the strongly temperature dependent morphotropic phaseboundary (MPB) and is discussed in the literature as a possible alternative to lead based
piezoceramics. Structural reports suggest the coexistence of rhombohedral and tetragonal phases at
the MPB that result in the impressive properties.134
In the present study compositions across the MPB are investigated ranging from single
rhombohedral to single tetragonal symmetries, including one MPB composition. The individual
180° and non-180° domain processes are studied as a function of the electric poling history bymeans of large signal polarization and strain, small signal permittivity and piezoelectriccoefficients, as well as in situ synchrotron x-ray diffraction. Non-180° (ferroelastic) domain
processes can be clearly identified by electric field dependent small signal permittivity
measurements as well as by electric fielddependent XRD.
Rietveld analysis of diffraction data using"Materials
Analysis
Using
Diffraction"(MAUD)135 reveals a very large electricallyinduced ferroelastic domain texture. For an
applied electric field the domain alignment
exceeds 85% in tetragonal BZT-BCT materials.
At zero field a large relaxation of the domain
texture is observed, which suggests that each field
cycle leads to a strong ferroelastic domain Fig. 40: Development of a large ferroelastic domain
reorientation. Moreover, the refined lattice texture for an applied electric field, with domain
parameters enable quantification of intrinsic and alignment of over 85%.
extrinsic contributions to the piezoelectriccoefficient as a function of orientation. The large macroscopic piezoelectric response observed fromelectric measurements is discussed and related to the complex strain anisotropy in the
microstructure and the extraordinary domain alignment developed under field as observed from insitu XRD. The results presented give insight into the design objectives of new lead-freepiezoelectric materials.
134

W. Liu and X. Ren, Phys. Rev. Lett. 103, 257602 (2009).
L. Lutterotti, M. Bortolotti, G. Ischia, I. Lonardelli, and H. R. Wenk, Zeitschrift für Kristallographie Supplements
2007, 125 (2007).
135

Multiferroics
CLUB B
Tuesday, July 23 2013, 02:00 pm - 03:30 pm
Chair:

Ruediger-A. Eichel
Forschungszentrum JuelichISAF2-E2-1 _____________________________________________________________________________________________________________________

Direct Observation of Electric and Magnetic Field induced
Ferroelectric Switching in a Room Temperature Multiferroic
D. M. Evans1*, M. Arredondo1, A. Schilling1, Ashok Kumar2,3, D. Sanchez2, N. Ortega2, R. S.
Katiyar2, J. F. Scott4 and J. M. Gregg1
1

School of Mathematics and Physics, Queen's University Belfast, Belfast, N. Ireland, BT7 1NN,UK.
2
Department of Physics and Institute of Multifunctional Materials, University of Puerto Rico, San
Juan, P.R., USA.
3
Materials Physics and Engineering Division, National Physical Laboratory, New Delhi-110012,
India
4
Department of Physics, Cavendish Laboratory, J. J. Thomson Ave., Cambridge, CB3 0HE, UK.
Email: devans92@qub.ac.uk

For any material to realize a multiferroic device there must be coupling between the ferromagnetismand ferroelectricity. This has been shown at low temperature by switching magnetically andelectrically as far back as the 60s [1]. However, it was not until 2006 that any form of coupling wasdemonstrated at room temperature [2]. Zhao et al. switched antiferromagnetic domains in BiFeO3
using an electric field. Despite this progress in switching antiferromagnetic domains no one has
directly observed switching, at room temperature, of ferromagnetic domains by using an electricfield, or ferroelectric domains by using a magnetic field.
In this talk, we will show electrical switching in a co-planar geometry, imaged with a PFM, we thenshow how a comparable remanent ferroelectric domains pattern can be achieved with a magnetic
field; the authors believe this is the first demonstration of equivalence between electric andmagnetic field at room temperature. TEM is used to investigate the domain hierarchy and to look at
preliminary evidence that coupling occurs on the lowest level of hierarchy, on a scale of order tensof nanometers. Finally we gain an order of magnitude estimate for the effective magnetoelectric
coupling coefficient[4] and compare it to other values in the literature. All our samples are single
crystal slabs of ca. (PbZr0.53Ti0.47O3)0.6-(PbFe0.5Ta0.5O3)0.4 cut from single grains of bulk
multiferroic ceramics [3] by using a Focused Ion Beam Microscope.

[1] E. Ascher et al., J. Appl. Phys. 37, 1404-1405, 1966
[2] T. Zhao et al., Nat. Mater. 5, 823 – 829, 2006
[3] D. Sanchez et al., AIP Adv. 1, 042169, 2011[4] D. M. Evans et al., Nat. Comms. 4, 1534 (2013)

ISAF2-E2-2 _____________________________________________________________________________________________________________________

Influence of Composition on the Multiferroic Properties oflayer Bi6TixFeyMnzO18 Aurivillius Phase Thin Films

5-

Lynette Keeney1, Ahmad Faraz1, Nitin Deepak1, Tuhin Maity1, Michael Schmidt1, Andreas Amann1,
2, Nikolay Petkov1, Saibal Roy1, Martyn E. Pemble1,3, Roger W. Whatmore1,3.
12Tyndall National Institute, University College Cork, Cork, Ireland
School of Mathematical Sciences, University College Cork, Cork, Ireland
3
Department of Chemistry, University College Cork, Cork, Ireland
Email: lynette.keeney@tyndall.ie

Single-phase, room temperature magnetoelectric multiferroic materials are of considerable interestfor potential applications in sensors and spin-based memory/logic devices136 as a result of theirability to induce a change in magnetization by an applied electric field or electric polarization by amagnetic field. However, such materials are exceptionally scarce. Recently137, Aurivillius phasethin films prepared by a chemical solution deposition method, having an average film compositionof Bi6Ti2.8Fe1.52Mn0.68O18 (B6TFMO), demonstrated both ferroelectric and ferromagnetic hysteresis
at room temperature. Microstructural analysis concluded that the multiferroic behaviour does not
originate from impurity phases to a confidence level of 99.5%. Piezoresponse force microscopy(PFM) investigations as a function of applied magnetic field demonstrated magnetic field induced
switching of ferroelectric polarisation in individual grains at room temperature (Fig. 1). This
present work will report the effect of Ti/Fe/Mn compositional ratios on the multiferroic properties
of B6TFMO thin films prepared on sapphire substrates by chemical solution deposition. Structural,
ferroelectric (PFM), magnetic (superconducting quantum interference device magnetometry) andmagnetoelectric (PFM under magnetic field) properties are assessed and an optimised B6TFMO
composition selected for the growth of thin films with controlled orientation and texture by atomic
vapour deposition (AVD).138

Fig. 1: Representative PFM phase images of B6TFMO thinfilms on c-plane sapphire under (a) 0 mT, (b) 250 mT and (c)136Emerging Research Device Materials, -250
ITRS,mT.
2009 Edition
137

L. Keeney, T. Maity, M. Schmidt, A. Amann, N. Deepak, N. Petkov, S. Roy, M. E. Pemble and R. W. Whatmore,
Magnetic-Field-Induced Ferroelectric Switching in Multiferroic Aurivillius Phase Thin Films at Room Temperature”,
submitted.
138
The support of SFI under the FORME SRC Award number 07/SRC/I1172 and FP7-PEOPLE-2011 under the
NANOMOTION Grant Agreement Number 290158 is gratefully acknowledged.
“

ISAF2-E2-3 _____________________________________________________________________________________________________________________

Application of PMN-PT ferroelectric relaxor for multiferroic
random access memory cell
Nicolas Tiercelin1, Yannick Dusch1, Alexey Klimov2, Stefano Giordano1, Arnaud Stolz1, Vladimir
Preobrazhensky3 and Philippe Pernod1
International Associated Laboratory LICS/LEMAC :IEMN UMR CNRS 8520, PRES Lille Nord de France, ECLille, Villeneuve d'Ascq, France
2
V. A. Kotel’nikov Institute of Radioengineering and Electronics, 125009 Moscow, Russia
3
Wave Research Center, GPI RAS, Moscow, Russia

1

Email: Nicolas.tiercelin@iemn.univ-lille1.fr - Preobr@newmail.ru
The renaissance of multiferroics139 has triggered a quest for magnetoelectric memories, offering
non-volatility, endurance, high switching speeds and ultra-low power operation. In 2010, Tiercelin
et al.140 proposed a concept for magnetoelectric random access memory (MELRAM) based onstress-mediated composite multiferroic. Theoretical studies of the expected performances have beenpresented141 and a macroscopic proof of the concept was provided 142. In this system electric field
allows switching between two orthogonal magnetic states ''0'' or ''1'' in plane of magnetostrictive
subsystem. In order to be successfully integrated in practical devices, one must find an efficient way
to generate inplane anisotropic stress in a simple planar structure with vertical dielectric
polarisation. We show here that the ferroelectric relaxors of the PMN-PT type, cut in the <011>
plane are suitable candidates for MELRAM cell
design. For demonstration we sputtered themagnetostrictive
nanostructure
10*[(TbCo2)5nm/(FeCo)5nm] on commercial <011>
PMN-PT single crystal substrate (fig.1). A
magnetic easy axis (EA) was induced in plane byapplication of static magnetic field during
sputtering.
External
magnetic
field
HSperpendicular to the EA created two energeticallyequivalent magnetic states. Application of apositive voltage pulse to the planar electrodes
induced orientation of magnetisation in the position''1'', whereas a negative pulse switchedmagnetisation to the position ''0''. The switchingprocess was detected by magneto-optic Kerr effect(MOKE). The results of MOKE signal Fig. 41: Prototype of MELRAM cell andmeasurements are shown on fig.1. The experimental evidence of by electric fieldmagnetisation switching in magnetostrictive
nanostructure deposited on single crystal PMN-PT
substrate.

139

N. Spaldin, and M. Fiebig, Science, 309 (5733), 391-392, 2005.

140

N. Tiercelin, Y. Dusch, V. Preobrazhensky, and P. Pernod, J. Appl. Phys. 109, 07D726, 2011.

141

S. Giordano, Y.Dusch, N. Tiercelin, P. Pernod and V. Preobrazhensky, Phys.Rev.B 85, 155321,2012.

142

N. Tiercelin, Y. Dusch, A. Klimov, S. Giordano, V. Preobrazhensky, P. Pernod, Appl.Phys.Lett. 99, 192507, 2011

characteristics of cell and prospective of MELRAM technology are discussed.

ISAF2-E2-4 _____________________________________________________________________________________________________________________

Spin dynamics controlled by strain in BiFeO3 films
Daniel Sando1, Arsène Agbelele3, Dovran Rahmedov4, Ingrid C. Infante2, Alexander Pyatakov6,
Laurent Bellaiche4, Stephane Fusil1, Cecile Carretero1, Eric Jacquet1, Cyrile Deranlot1, Sergey
Lisenkov7, Dawei Wang8, Jean-Marie Le Breton3, Maximilien Cazayous5, Alain Sacuto5, Jean
Juraszek3, Anatoly Zvezdin6, Agnès Barthélémy1, Brahim Dkhil2, Manuel Bibes1
1

Unité Mixte de Physique CNRS/Thalès UMR137, Palaiseau, France
Ecole Centrale Paris/CNRS UMR8580, Chatenay-Malabry, France
3
Université de Rouen/CNRS UMR6634, Rouen, France
4
Physics Department, University of Arkansas, Fayetteville, Arkansas, United States
5
Université Paris 7/CNRS UMR7162, Paris, France
6
Russian Academy of Sciences, Moscow, Russian Federation
7
University of South Florida, Tampa, FL, United States
8
Xi’an Jiaotong University, Xi’an,China
2

Email: ingrid.canero-infante@ecp.fr
Multiferroics are considered as ideal materials to combine magnetic control of polarization andconversely, electric control of magnetization, as they show (within the same phase) ferroelectric andmagnetic orders. Among these materials, BiFeO3 has been by far the most investigated, mainly
because it is one of the few room temperature multiferroics. Bulk BiFeO3 is characterized by a large
ferroelectric polarization coexisting with a G-type antiferromagnetic order and a spin cycloid. Whengrown in thin film form, the epitaxial strain has been shown to induce important distortions on unit
cell causing a drift of the ferroelectric transition143 and eventually the stabilization of new phases144.
In the present work145, we explore the less studied effects of epitaxial strain on spin dynamics of
BiFeO3 films. By combining Mössbauer and Raman spectroscopies with Landau-Ginzburg andeffective Hamiltonian calculations, we have evidenced that a spin cycloid modulation exists in
BiFeO3 thin films at small and moderate strains and disappears at high tensile and compressive
strains. We have also observed that the average spin orientation evolves from in-plane to out ofplane directions when the strain changes from compressive to tensile, which leads to a strong
modification of spin dynamics in these films. The interface effects and coupling to otherferromagnetic layers through exchange bias effects will also be presented and discussed in the spiritof proposing and proving direct applications in tuning the conduction in giant magnetoresistive spin
valves.

143

I. C. Infante et al. Phys. Rev. Lett. 105, 057601 (2010)

144

R. J. Zeches et al. Science 326, 977 (2009) ; B. Dupé et al., Phys. Rev. B 81, 144128 (2010)145

D. Sando et al., Nature Materials, in press

ISAF2-E2-5 _____________________________________________________________________________________________________________________On the chemical stability and charged point defects in BiFeO 3materials
Tor Grande1
1Department of Materials Science and Engineering,
Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
Email: grande@ntnu.no
The rhombohedral perovskite BiFeO3 has become the centre of research on multiferroics due to its
robust room-temperature multiferroism with a Néel temperature of 370 °C and a Curie temperatureof 820–830 °C.146 Beside the multferroic properties BiFeO3 is also interesting because of its highintrinsic polarization of ~ 100 μC/cm2, which is along the pseudocubic (111) direction. A
tremendous amount of work has been reported on BiFeO3 thin films, single crystals and bulk
ceramics,1 but particularly the investigations on bulk BiFeO3 ceramics have been hampered by thesevere difficulties to prepare single phase materials and the problems with dielectric loss caused by
the high electronic conductivity of BiFeO3.
We will first focus on the thermodynamic stability of BiFeO3, particularly with respect to thecompeting reaction to form the phases Bi25FeO39 and Bi2Fe4O9 on the expense of BiFeO3.147 The
thermodynamic stability of BiFeO3 and related Bi-based perovskites is discussed in relation toGoldschmidt tolerance factor and the influence of pressure/strain and chemical substitution.
The thermodynamic stability and properties of BiFeO3 is also influenced by the volatility of Bi2O3
at elevated temperatures. The corresponding loss of PbO in PZT materials is known to have apronounced effect on the functional properties of traditional lead-based ferroelectric materials, andhere will discuss possible influence of charged point defects in the BiFeO3-materials due to loss of
Bi2O3. Volatilization of Bi2O3 will create charged point defects in the perovskite lattice, more
precisely Bi and O vacancies. These point defects may have detrimental effects on the properties ofbulk BiFeO3 ceramics mainly due to two different reasons.
First, the oxygen vacancies formed due to Bi2O3 loss may influence on the oxidations state Fe andthereby on the electrical conductivity of BiFeO3. Iron is Fe3+ in stoichiometric BiFeO3, but may
oxidize to Fe4+ due to available oxygen vacancies leading to increasing p-type conductivity.148 We
will discuss the influence of the atmosphere during thermal annealing by examples from (1-x)
Bi0.5K0.5TiO3 – x BiFeO3 (BKT-BFO) solid solutions.149
Finally, point defects may also strongly influence on the domain wall mobility in BiFeO3, asrecently discussed by Rojac et al.150 Strategies to reduce the influence of point defects and thereby

146

G. Catalan, J.F. Scott “Physics and applications of bismuth ferrite”, Adv. Mater., vol. 21, p. 2463 -2485, 2009.

147

S.M. Selbach et al. “On the thermodynamic stability of BiFeO 3”, Chem. Mater., vol. 21, p. 169-173, 2009.
148
S.M. Selbach, T. Tybell, M.-A. Einarsrud, T. Grande “Phase transitions, electrical conductivity and chemical
stability of BiFeO3 at high temperature”, J. Solid State Chem., vol. 183, p. 1205-1208, 2010.
149

M. I. Morozov, M.-A. Einarsrud, T. Grande., “Polarization and strain response in Bi 0.5K0.5TiO3 – BiFeO3 ceramics”,
Appl. Phys. Lett., vol. 101, 252904, 2012.
150

T. Rojac, M. Kosec, B. Budic, N. Setter, D. Damjanovic “Strong ferroelectric domain-wall pinning in BiFeO3
ceramics”, J. Appl. Phys. vol. 108, 074107, 2010.

softening of BiFeO3 is discussed with particular emphasis on the atmosphere during annealing andchemical substitution of Fe with Ti, which reduces the oxygen vacancy concentration.

PFM4CLUB C
Tuesday, July 23 2013, 02:00 pm - 03:30 pm
Chair:To Be Aannounced

PFM-E3-1 ______________________________________________________________________________________________________________________

Polarization-Related Electronic Properties of Complex Oxides
Alexei Gruverman
Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588, USA

Recently it was demonstrated that the conductivity of the LaAlO3/SrTiO3 (LAO-STO)
interface can be reversibly tuned through a switchable electromechanical response arising from the
LAO overlayer in the LAO-STO heterostructures. Bulk LaAlO3 (LAO) is a typical perovskite,which shows paraelectric behavior at room temperature. In this study, we have investigatedswitchable dielectric propeties of the LAO ultrathin (several unit cells) films grown on top oflattice-matched conducting oxide Sr0.2Ca0.8RuO3 (SCRO) on the (001) (LaAlO3)0.3–(Sr2AlTaO3)0.7(LSAT) substrate. Piezoresponse force microscopy (PFM) studies performed on the
LAO/SCRO/LSAT heterostructures show a genuine switchable hysteretic electromechanicalbehavior resembling that one observed in ferroelectric films associated with induced polarization in
the LAO layer. An insight into the underlying mechanism of such behavior has been gained byusing temperature-dependent PFM spectroscopic, dielectric and structural measurements. The effectof inhomogeneous strain gradient induced by the PFM probe on polarization in LAO has been alsostudied. The proposed mechanism of switchable electromechanical response should be active inmany other oxide heterosystems, but its detailed manifestation likely depends on a number ofsubtleties, such as oxygen octahedra rotations and distortions, strain, and lattice coupling at thenanoscale. Control of this phenomenon will enable new structures and devices that exploit
nanoscale electromechanical coupling.

PFM-E3-2 ______________________________________________________________________________________________________________________

Minimum domain size and stability in carbon nanotubeferroelectric devices
Cédric Blaser and Patrycja Paruch
MaNEP-DPMC, University of Geneva, Switzerland
Email: cedric.blaser@unige.ch
When combining carbon nanotubes (CNTs) with ferroelectric materials, the small size andexceptional electronic properties of the former makes them extremely interesting as local fieldsources for nanoscale ferroelectric polarization switching. Meanwhile, the ferroelectric polarization
can be used to modulate the electronic behavior of an adjacent CNT, leading to potentiallymultifunctional devices.
We deposited single-walled CNTs from aqueous suspension onto patterned epitaxial ferroelectric
Pb(Zr0.2Ti0.8)O3 (PZT) thin films. Using this device, PFM is used to probe domain switching inthree different electrode configurations, using an AFM tip, edges of macroscopic planar electrodes
and CNTs on the ferroelectric surface as electric field sources, allowing us to separately consider
the effects of the separation between two straight domain walls, and the radius of curvature on
domain stability151.
Domain growth dynamics in the three configurations are discussed using finite element analysis of
the vertical electric field vs. distance dependence, and in comparison with previously reported
ferroelectric nanodomains and thermodynamic models of switching.
In 270 nm thick films, we demonstrate domain sizes down to 9 nm half-with using a CNT electrode(see Fig. 1) and 14.5 nm radius with the AFM tip as electrode, two times smaller than the minimum
domain size predicted from thermodynamic models. The observed domains remained stable over 20months. These results suggest that the internal defect structure plays a significant role in the
dynamic and stability of ferroelectric nanodomains.
Fig. 1: (a) PFM phase image
after a +10 V, 10 µs pulse,with the switched domain
following the shape of theelectrically connected CNT.
Zoom on the thinnest
continuous domain in (b)PFM phase and (c) PFM
amplitude. (d) PFM phaseand amplitude signals acrossthe outlined area in (b)/(c).

151

C. Blaser and P. Paruch, “Minimum domain size and stability in carbon nanotube -ferroelectric device”, Appl. Phys.
Lett., vol. 101, p. 142906, 2012.

PFM-E3-3 ______________________________________________________________________________________________________________________

Piezo and ferroelectric phases of glycine

Ensieh Hosseini1, Igor Bdikin2, Budhendra Singh2, Vladimir Bystrov1, Andrei Kholkin1
1

CICECO & Department of Materials and Ceramics Engineering, University of Aveiro, Aveiro,
Portugal
2
TEMA & Department of Mechanical Engineering, University of Aveiro, Aveiro, Portugal
Email: Seyedhosseini@ua.pt

Creating artificial biomimetic materials with multiple functions similar to those of living bodies, isan important frontier for advanced society in near future. Recently, electromechanical coupling inmany bio-organic materials has been revisited and several materials demonstrated properties similar
to their inorganic counterparts. Glycine (the simplest amino acid) is one of basic and importantelements in biology as it serves as building block for proteins. Several polymorphic forms withcompletely different physical properties are possible in glycine. In this work, glycine microcrystals
were grown on a conductive substrate under different conditions. The influence of various
parameters (e.g. concentration of solution, solvent, volume of microdroplets, temperature, humidity,
and type of substrates) on the formation of polymorph phases was evaluated using powder X-ray
diffraction. The results indicated that the saturated solution and lower temperature lead to formationof γ phase whereas the β phase can be grown from low concentrated solution.
The piezoelectric response and ferroelectric domains of the different polymorphic forms of glycine
crystals have been investigated locally by using Piezoresponse Force Microscopy (PFM). The
domain switching properties are studied for crystals by applying a dc voltage to a localized area.
The results showed that the switching domains growth in different shape depends on thepolarization direction of the sample.
In addition, a molecular dynamics simulation was used for modeling the crystal structure of glycine
and the spontaneous polarization was determined and compared with experimental results. Also, themechanisms of polarization switching on the nanoscale level were investigated via this model.
The major part of this work was supported by the Marie-Curie ITN project “Nanomotion”

PFM-E3-4 ______________________________________________________________________________________________________________________

Piezoelectricity in Biopolymers and
DNA Nucleobase Crystals
Brian J. Rodriguez1
1

School of Physics, University College Dublin, Ireland
Email: brian.rodriguez@ucd.ie

Piezoelectricity is a property of many organic and biological materials, including collagen,nucleobase crystals, and peptide nanostructures. Recent progress in understanding the origin androle of piezoelectricity and possible ferroelectricity in these materials will be discussed.
Piezoelectric properties of collagen, etc. can be measured using piezoresponse force microscopy(PFM), which is a voltage-modulated contact mode atomic force microscopy technique that allows
bias-induced surface deformations via the converse piezoelectric effect to be detected. Thus, PFM
makes it possible to investigate electromechanical coupling in biosystems and organic materials at
the nanoscale.
Recently, PFM was used to study polar ordering in tendon, eye tissues, and collagenhydrogels.152,153 Collagen shear piezoelectricity is a functional property that may be associated withbone remodeling, however, the biofunctional implications of piezoelectricity in collagen and otherbiomaterials has yet to be clearly demonstrated. A preliminary step towards this goal is to determine
if collagen is piezoelectric in physiological conditions, which involves understanding the role of pH
and moisture content. Here, we investigate the structure and piezoelectric properties of aligned
collagen membranes before and after a neutralization process, which alters the pH from acidic toneutral conditions. Electromechanical properties of the collagen membranes have been further
investigated under controlled humidity conditions to probe whether collagen is piezoelectric inmoisture rich environments. In addition, the orientation dependence of collagen fibril piezoresponseis explored using cross sections of embedded tendons.
An early biopolymer identified as being piezoelectric was deoxyribonucleic acid (DNA).154 DNA
comprises the nucleobases adenine, cytosine, guanine, and thymine, which are held by backbones of
deoxyribose and phosphate. Thymine and other nucleobase crystals grown from solutions during
evaporation have been found to exhibit piezoelectricity, and in some cases contain domains which
can be switched via external field. The results are complemented using second harmonic generation
measurements.
The discovery of piezoelectricity in peptide nanotubes has helped to propel the field of PFM of
biomaterials. Peptides are short chains of amino acids and are the building blocks of all structural
tissues and are inherently “biocompatible.” Not only are peptide nanotubes piezoelectric but so are
dried peptide hydrogels. The differences in piezoresponse from the two materials will be analyzed.

152

D. Denning et al. “Visualizing Molecular Polar Order in Tissues via Electromechanical Coupling”, J. Struc t. Bio.,vol. 180, p. 409–419, 2012.
153
D. Denning et al. “Electromechanical properties of dried tendon and iso-electrically focused collagen hydrogels”,
Acta Biomater., vol. 8, p. 3073–3079, 2012.
154
E. Fukada “History and recent progress in piezoelectric polymers”, IEEE Trans. Ultra. Ferro. Freq. Control, vol. 47,
1277-1290 2000.

Furthermore, the outlook for future measurements and applications of piezoelectric collagen,nucleobase crystals, and peptide nanostructures will be discussed.

Lead-free ceramics: Spectroscopy
CLUB A
Tuesday, July 23 2013, 04:30 pm - 06:00 pm
Chair:

Jirka Hlinka
Institute of Physics, Czech Academy of Sciences

ISAF3-F1-1 _____________________________________________________________________________________________________________________

Two excitations below phonon frequencies in broad-banddielectric response of Ba(Zr,Ti)O3 ceramics
Dmitry Nuzhnyy1, Jan Petzelt1, Maxim Savinov1, Viktor Bovtun1, Martin Kempa1,
Giovanna Canu2, Maria Teresa Buscaglia2, Vincenzo Buscaglia2
1
Department of Dielectrics, Institute of Physics, Academy of Sciences of the Czech Republic,
Prague, Czech Republic2
Electroceramic Department, Institute for Energetics and Interphases, National Research Council
Genoa, Italy
Email: nuzhnyj@fzu.cz
Lead-free perovskite systems attract attention due to their potential use in a wide range ofapplications (piezoelectric transducers, phase shifters, tunable filters etc.). They are considered as
good candidates for the replacement of lead-based materials. Dielectric properties of theBa(Zr,Ti)O3 solid solution are changing dramatically with the ratio of Zr/Ti-ions. This allows fortuning the dielectric properties from slightly incipient ferroelectric behaviour (BaZrO3) throughrelaxor to diffuse and normal ferroelectric behavior (BaTiO3).
We have already investigated a set of Ba(Zr,Ti)O3 ceramics155 and observed an excitation whichsoftened from THz either to GHz (BaZr0.2Ti0.8O3) or to MHz (BaZr0.4Ti0.6O3) range where it merged
into a constant-loss background. This feature in dielectric response we considered as one
overdamped excitation associated with local hopping of Ti-ions among their off-centered sites. To
prove this picture, we needed similar data for smaller Ti concentration, since the hopping dynamics
of Ti ions is not expected to be much dependent on the size of the Ti clusters. In order to obtainthese data we prepared another set of Ba(Zr,Ti)O3 ceramics with higher concentration of Zr (x=0.6,
0.7, 0.8) using solid-state reaction technique. These compounds were studied in 5 - 500 K
temperature range using Fourier-transform infrared reflectivity, time-domain THz transmission
spectroscopy, high-frequency - microwave coaxial technique, and standard low-frequency
capacitance spectroscopy. This enabled us to obtain the dielectric response in the whole range from
1Hz to 100 THz and fit it with phenomenological models.
Even though there is a gap in our experimental data (~109-1011 Hz), careful fitting of the data atvarious temperatures led us to the conclusion that two relaxations are needed to fit the dielectric
response in the whole frequency range. The high frequency relaxation (~1010-1011 Hz) is almost
temperature independent for all investigated compounds, while another broad relaxation isthermally activated, showing considerable softening on cooling from GHz range, similar for allcompositions in agreement with the Ti-hopping picture.

155

D. Nuzhnyy, J. Petzelt, M. Savinov, T. Ostapchuk, V. Bovtun, M. Kempa, J. Hlinka, V. Buscaglia, M. T. Buscaglia,
and P. Nanni, “Broadband dielectric response of Ba(Zr,Ti)O 3 ceramics: From incipient via relaxor and diffuse up toclassical ferroelectric behavior”, Phys. Rev. B, vol. 86, p. 014106(1)- 014106(9), 2012.

ISAF3-F1-2 _____________________________________________________________________________________________________________________

Impedance spectroscopy studies on Mn doped K0.5Na0.5NbO3
lead-free ferroelectric ceramics
Paula Maria Vilarinho, Muhammad Asif Rafiq, Maria Elisabete Costa,
Department of Materials and Ceramics Engineering, Centre for Research in Ceramics andComposite Materials, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
Email: paula.vilarinho@ua.pt
This talk is about a systematic study carried out by impedance spectroscopy to identify defects anddescribe their role in the conduction behaviour of undoped and Mn doped KNN ceramics. Oxygen
vacancies located at the grain boundaries were identified as responsible for the decrease of the
conductivity at room temperature and a less leaky behaviour of Mn doped KNN and also for the
conduction increase at elevated temperatures for these ceramics. The importance of this work
resides on the fact that K0.5Na0.5NbO3 (KNN) is one of the leading lead free piezoelectric materials
being considered as an alternative to Pb(Zrx,Ti1-x)O3 (PZT), which is currently the most widely usedmaterial for electromechanical applications156.
Smart materials like piezoelectrics and ferroelectrics are crucial in applications such as sensors andactuators, radio-frequency switching, drug delivery, chemicals detection, and power generation andstorage. Although pure KNN has inferior electromechanical properties compared to PZT, efforts areon going to tailor and improve its ferroelectric and piezoelectric coefficients by doping andtexturing1. Earlier reports have shown that the remnant polarization (Pr) values of KNN ceramics
may exceed the saturation polarization value157, thus indicating the presence of leakage current andspace charge contributions either in undoped or doped KNN (doped with Li and Ta, Li and Sb)
ceramics. Mn dopant has been used to reduce the leakage current in KNN single crystals but its
effects on the electrical properties of KNN ceramics have not yet been properly addressed and thus
remain unclear.
In this work Impedance spectroscopy (IS) is used to get a deeper insight into the electricalbehaviour of undoped and Mn doped KNN ceramics by assessing and distinguishing contributions
to the ceramic impedance arising from different regions, bulk and grain-boundary. Ac conductivity
dependence on the temperature showed that resistivity of Mn doped ceramics increased at room
temperature while the reverse was observed for temperature higher than 200 °C. Activation energy
values showed that hopping mechanism at room temperature and mobile oxygen vacancies are themain charge carrier at high temperature (T˃200 °C). Impedance spectroscopy revealed the main
location of the defects and the dependence of their contribution on the temperature. For low
temperatures, Mn decreases the conductivity of KNN and for high temperatures due to the increased
mobility of oxygen vacancies mainly located at the grain boundaries, the conductivity of Mn doped
KNN increases. This work is expected to contribute to the pool of knowledge on KNN materials
making them useable for industrial applications.

156
157

Y. Saito, H. Tani, et al., Lead-free piezoceramics. Nature, 432(7013), p. 84-87, 2004

H.E. Mgbemere, M. Hinterstein, et al., Structural phase transitions and electrical properties of (K xNa1-x)NbO3 based
ceramics modified with Mn. Journal of the European Ceramic Society, 32(16), p. 4341 -4352, 2012

ISAF3-F1-3 _____________________________________________________________________________________________________________________

defect-structure – property relationships: fundamental
differences between Pb[Zr,Ti]O3 and ‘lead-free’ alternative
compounds
Rüdiger-A. Eichel
Forschungszentrum Jülich, Institut für Energie und Klimaforschung (IEK-9), Germany
Email: r.eichel@fz-juelich.de

In order to meet the sometimes stringent requirements for specific piezoelectric applications, thematerials properties of ferroelectric oxides may be tailored by means of aliovalent doping withtransition-metal or rare-earth ions. The main effect of aliovalent doping is to control the defectstructure in terms of the generation or annihilation of lattice vacancies158, which renders compoundswith so-termed 'hard' or 'soft' ferroelectric properties. With that respect, the hardening mechanism is
attributed to the formation of dipolar complexes between the acceptor ion and charge compensating
oxygen vacancies. As a result, the orientation of spontaneous polarization in the neighbouring unit
cells as well as the domain structure and domain-wall mobility are impacted.
By using multi-frequency electron paramagnetic resonance (EPR) spectroscopy159, local
information at the (paramagnetic) dopant sites can be gathered, including information about the
dopant site with respect to domain walls or grain boundaries160. Recent results allow to monitor theformation of defect complexes between acceptor-type dopants and charge-compensating oxygen
vacancies. Furthermore, a complete defect chemical description upon aliovalent doping emerges
from the EPR results.
Most interestingly, the results obtained for the pseudo-binary solid-solution system
Pb[Zr1-xTix]O3 (PZT) cannot simply be transferred to ‘lead-free’ alternative compounds, such as[Ka0.5Na0.5]NbO3 (KNN)161 or [Bi0.5Na0.5]TiO3 (BNT)162 for instance. Differences in defectstructure also impact the dynamic properties as function of switching upon external poling163.

158

E. Erdem, P. Jakes, S.K.S. Parashar, K. Kiraz, M. Somer, A. Rüdiger, R.-A Eichel,
J. Phys.: Condens. Matter 22 (2010) 345901.
159

R.-A. Eichel, Phys. Chem. Chem. Phys., 13 (2011) 368–384.

160

P. Jakes, E. Erdem, R.-A. Eichel, L. Jin, D. Damjanovic, Appl. Phys. Lett. 98 (2011) 072907.

161

E. Erünal, P. Jakes, S. Körbel, J. Acker, H. Kungl, C. Elsässer, M.J. Hoffmann, R. -A. Eichel,
Phys. Rev. B 84 (2011) 184113.
162

E. Aksel, P. Jakes, E. Erdem, D.M. Smyth, A. Ozarowski, J. van Tol, J.L. Jones, R.-A. Eichel,
J. Am. Ceram. Soc., 94 (2011) 1363–1367.
163

L.X. Zhang, E. Erdem, X. Ren, R.-A. Eichel, Appl. Phys. Lett. 93 (2008) 202901

ISAF3-F1-4 _____________________________________________________________________________________________________________________

Ferroelectric Phase Transition in nanostructured BaTiO3 studied by
Raman scattering and second harmonic generation.
A. M. Pugachev1, V. I. Kovalevskii1, V. K. Malinovsky1, N. V. Surovtsev1, Yu. M. Borzdov2
1
2

Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, Russia
V. S. Sobolev Institute of Geology and Mineralogy, Russian Academy of Sciences, Novosibirsk,
RussiaE-mail apg@iae.nsk.su

It is widely known that the ferroelectric phase transition from tetragonal to cubic phase in
BaTiO3 ceramics and powders is strongly suppressed compared with the crystals. In our study thefeatures of this transition were investigated by low - frequency Raman scattering and second
harmonic generation (SHG) techniques. The samples were prepared from the BaTiO3 powderpressed by using a uniaxial pressure of 600 MPa, 3*103 MPa and 4*103 MPa. Raman scattering
spectra were measured in a spectral range 1.5 – 650 cm-1 by a triple-grating spectrometer
TRIVISTA 777 for temperature range from 300 K to 800 K, covering both ferroelectric andparaelectric phases. Over the entire temperature range a well pronounced central peak (CP) was
detected. It was previously shown1,2 that in BaTiO3 crystals the central peak in a spectral densitypresentation I n  ,T   I  ,T  n( )  1 (here n() is the Bose factor) is well fitted by Lorentz
contour (single relaxation time approximation) and its width demonstrated a critical slowing downin the vicinity of the Curie temperature. In the case of single relaxation time the low frequency partof CP in a susceptibility presentation is described by power law: I r  ,T   I n  ,T     whereand  = 1. In contrast to crystals the CP in a spectral density presentation in a pressed powder can
not be fitted by Lorentz function and I r  ,T     where   0.07 in ferroelectric phase andincreased up to 0.8 with increasing the temperature up to 800 K in paraelectric phase. Such behaviorof the parameter  indicates that the relaxation process in the pressed powder can not be describedby a single relaxation time. The temperature dependence of  is typical for ferroelectrics with adiffuse phase transition (relaxors) as shown by the example of crystals SBN 613 and PMN4.
A study of second harmonic generation (SHG) in BaTiO3 pressed powder has been carried out by
the procedure described in5. It was found that the broadening of the phase transition is significantly
increased with the application of mechanical stress and increases monotonically with increasingstress up to Burns temperature (~ 600 K). The experimental data confirm that BaTiO3 ceramics andpowders in paraelectric phase exhibit much greater SHG intensity than in the crystals because of theexistence of the polar nanoregions in the paraelectric phase.
The obtained results of Raman and SHG experiments are interpreted as a relaxor - like behavior of
BaTiO3 pressed powder.
1.

2.

3.

4.

J.H. Ko, T. H.Kim, K. Roleder, D. Rytz, S. Kojima, “Precursor dynamics in the ferroelectric phase transition of
barium titanate single crystals studied by Brillouin light scattering” Phys. Rev. B 84, 094123, 2011
V. K. Malinovsky, A. M. Pugachev, V.A. Popova, N. V. Surovtsev, S. Kojima “Low frequency Raman scatteringin BaTiO3 crystal”, Feroelectrics, in press
Koreeda, H. Taniguchi, S. Saikan, and M. Itoh “Fractal Dynamics in a Single Crystal of a Relaxor Ferroelectric”,
PRL, 109, 197601, 2012
V. K. Malinovsky, A. M. Pugachev, N. V. Surovtsev “Study of the Central Peak in Raman Spectra of SBN
Crystals” Bulletin of the Russian Academy of Sciences: Physics, 74, No. 9, pp. 1231–1234, 2010.

5.

Pugachev A.M., Kovalevskii V.I., Surovtsev N.V., Kojima S., Prosandeev S.A., Raevski I.P., Raevskaya S.I.
“Broken local symmetry in paraelectric BaTiO 3 proved by second harmonic generation”, P.R.L., v.108., 247601,
2012 .

ISAF3-F1-5 _____________________________________________________________________________________________________________________

Non-linear Coupling between the Primary and Secondary OrderParameters of Strontium Titanate Ceramics
Ali Al-Zein1, Bernard Hehlen2, Christine Bogicevic3, Pascale Gemeiner3, Jean-Michel Kiat3,4
1

European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, Grenoble, France
Laboratoire Charles Coulomb (LCC), CNRS-UMR 5221, Université Montpellier II, France
3
Laboratoire Structures, Propriétés et Modélisation des Solides, Ecole Centrale Paris, CNRSUMR8580, Châtenay Malabry, France
4
Laboratoire Léon Brillouin, CE Saclay CNRS-UMR12, Gif-Sur-Yvette, France
2

Email: alzein@esrf.fr
SrTiO3 (STO) is a textbook example of quantum paraelectric materials with very high value of thedielectric constant at low temperature. It exhibits an anti-ferrodistortive cubic (Pm-3m) to tetragonal(I4mcm) phase transition at Ta = 105 K [1]. In bulk material, its primary (rotation angle  of the
TiO6 octahedra) and secondary (spontaneous strain c/a-1) order parameters are linearly coupledwith 2  c/a-1. In STO ceramics, a core-shell structure was assumed to interpret the behavior of
the low-temperature permittivity, with probably a static polarization in the shell and large stressfields affecting the core grain [2].
Neutron diffraction, Raman and hyper-Raman (HRS) scattering have been used to study the
structural and vibrational properties of micrograin and nanograin STO ceramics. HRS spectroscopyof micrograin STO ceramics revealed a splitting of the soft F1u mode into a A2u and Eu vibrations[3]. This was not observed by previous Raman scattering or infrared absorption studies.
Interestingly, this splitting occurs at about
90 K that is, at a much lower temperaturethan 160 K [4] at which the tilting of the
TiO6 octahedra starts growing. Thisobservation suggests a nonlinear coupling
between the two order parameters (Figure)[3]. Such behavior possibly arises from thestrain field the shell imposes on the coregrain and one therefore expects that it isstrongly dependent on the synthesis routeand grain size.

[1] K.A. Muller, W. Berlinger, and F. Waldner, Phys. Rev. Lett. 21, 814 (1968).
[2] J. Petzelt, T. Ostapchuk, I. Gregora, P. Kuzel, J. Liu, and Z. Shen, J. Phys.: Condens. Matter. 19, 196222 (2007).
[3] B. Hehlen, A. Al-Zein, C. Bogicevic, P. Geimener, and J-M. Kiat, Phys. Rev. B 87, 014303 (2013).

[4] J. M. Kiat, C. Bogicevic, P. Geimener, A. Al-Zein, F. Karolak, N. Guiblin, F. Porcher, B. Hehlen, Ll. Yedra, S.
Estradé, F. Peiro and R. Haumont, Phys. Rev. B. 87, 024106 (2013).

Multiferroics
CLUB B
Tuesday, July 23 2013, 04:30 pm - 06:00 pm
Chair:Tor Grande
Norwegian University of Science and Technology

ISAF3-F2-1 _____________________________________________________________________________________________________________________

Raman spectroscopy for characterization of crystalline phases
and phase transformations in BiVO4 and BiFeO3 films
D. A. Tenne1, A. K. Farrar1, J. B. Romero1, D. A. Hillsberry1, S. Stoughton,2 M. Showak,2 , C.
Heikes2, J. H. Lee2, A. Melville2, C. Adamo2, Q. Mao,3 L. F. Kourkoutis,3 D. A. Muller,3 C.
Beekman4, W. Siemons,4 T.Z. Ward4, M. Chi,4 J. Howe,4 M.D. Biegalski5, N. Balke5, P.
Maksymovych5, H. M. Christen4, and D. G. Schlom2
1

Department of Physics, Boise State University, Boise, ID 83725, USA
Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA
3
School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
4
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN,37831, USA
5
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831,
USA
2

Email: dmitritenne@boisestate.edu
Raman spectroscopy is a technique capable of distinguishing crystalline polymorphs and detecting
phase transitions between different crystal structures in bulk and thin film solids. In this work it wasapplied to study strained thin films of photocatalytic BiVO4 and multiferroic BiFeO3. Bulk BiVO4
is known to exist in several crystalline forms (polymorphs), and the monoclinic polymorph of
BiVO4 is believed to have the best photocatalytic properties for water splitting using solar energy.
The BiV04 films studied were grown by molecular beam epitaxy on yittria-stabilized cubic zirconia
substrate. Raman spectra were measured at 10 and 300 K with several excitation laser lines in therange from 325 to 514.5 nm, and 441.6 nm line was found to produce the strongest Raman signal
from BiVO4, because of its proximity to the resonance with the bandgap of BiVO4. The analysis of
the Raman spectra indicated that the film was of monoclinic structure, as expected for the growth
conditions used and consistent with x-ray diffraction and scanning transmission electron
microscopy data.
Coherently strained BiFeO3 films were grown by molecular beam epitaxy and pulsed laser
deposition on various substrates including YAIO3, LaAIO3, NdGaO3, SrTiO3, and ReScO3 (Re = Pr,
Sm, Gd, Tb, Dy). These substrates induce lattice-mismatch biaxial strain in BiFeO3 films spanninga range from –6.7% to +1.4%. The films have been studied by variable-temperature Raman
spectroscopy with ultraviolet excitation (325 nm) in order to reduce the substrate contribution tospectra. At low temperatures, a large number of BiFeO3 phonon peaks observed in spectra indicatesthe structure to be monoclinically distorted (Cc). Temperature evolution of Raman spectra from
BiFeO3 films under large compressive strain (above 4%) indicates the phase transitions to anothermonoclinic phase, then to tetragonal phase (at ~ 730 K for the films on LaAlO3). Raman spectra(measured up to 950 K), demonstrate that the high temperature phases are still polar; a linear
extrapolation of Raman intensities yields an estimated Curie temperature at 867  100 C for
BiFeO3 under 4.4% compressive strain. Tensile-strained films (on PrScO3 substrates, strain +1.4%)
undergo a transition from monoclinic rhombohedral-like to orthorhombic-like phase at about 550–
600 K. The temperature dependence of Raman intensities of certain characteristic peaks indicatesthe possibility of coexisting phases in the temperature range 400–550 K.

Supported in part by the National Science Foundation through the Grant DMR-1006136.

ISAF3-F2-2 _____________________________________________________________________________________________________________________

Electromagnons and sequence of structural and magnetic phasetransitions in multiferroic CaMn7O12
S. Kamba1, V. Goian1, F. Kadlec1, J. Hejtmánek1, M. Savinov1, P. Vaněk1, and M. Orlita2

1

Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
2
Grenoble High Magnetic Field Lab, Grenoble, France
Email: kamba@fzu.cz

CaMn7O12 is an unusual material which exhibits a rich sequence of structural, ferroelectric andmagnetic phase transitions. At high temperatures, (CaMn3)Mn4O12 crystallizes in the cubic
perovskite structure (space group Im 3 ) and upon cooling below Tc1 ~ 450 K charge ordering occurs
which induces a structural transition to a trigonal phase with the space group R3 (Z=3). Below Tc2=250 K, orbital ordering occurs and the trigonal structure becomes incommensurately modulatedwith a propagation vector qc=(0,0,2.077).164 Upon further cooling below TN1=90 K, an
incommensurately modulated magnetic structure emerges with a magnetic modulation vector qm =
½qc.164 Very recently, it was reported165 that the magnetic structure is also ferroelectric with aspontaneous polarization attaining up to Ps=2870 Cm-2 oriented parallel to the c axis. This is thehighest spin-induced polarization among all multiferroics. At TN2=50 K, another magnetic transition
occurs, giving rise to a second propagation vector along the c axis. Both propagation vectors qm1
and qm2 change with temperature, but their average value corresponds exactly to ½qc.
We have investigated far-IR reflectivity and time-domain THz transmission spectra of CaMn7O12
between 10 and 550 K and found significant changes in the spectra at structural and magnetic phasetransitions. The IR reflectivity changes abruptly at Tc1 = 450 K, giving evidence of the first-ordercharacter of the phase transition. Moreover, the conductivity seen in the high-temperature IR
spectra disappears below Tc1, proving the metal-insulator character of this phase transition due tocharge ordering. New polar phonons appear in the spectra in the incommensurate phase below 250
K due to a change of IR selection rules. Close to TN1, a new mode develops near 50 cm-1; anotherone near 30 cm-1 appears below TN2. Since the modes appear near the magnetic phase transitions,they can be spin waves (magnons). Nevertheless, IR reflectivity spectra reveal a transfer of theoscillator strengths from the phonons to the excitations seen below 50 cm-1. Thus, the modes at 30
and 50 cm-1 contribute to the dielectric permittivity and not to the magnetic susceptibility. This is atypical signature of electromagnons, i.e. electric active magnons, which are activated in THz
dielectric spectra due to dynamical magnetoelectric coupling. The origin of magnetoelectric
coupling in CaMn7O12 will be analyzed and discussed.
Low-temperature far-IR transmission spectra measured under magnetic field up to 12 T revealed
significant shifts of electromagnon frequencies with magnetic field. These shifts are responsible fora large dependence of low-frequency dielectric permittivity on applied static magnetic field(magneto-dielectric effect), which we as well investigated.
164

N.J. Perks, R.D. Johnson, C. Martin, L.C. Chapon, and P.G. Radaeli, “Magneto-orbital helices as a route to coupling
magnetism and ferroelectricity in multiferroic CaMn7O12 ”, Nature Commun.vol. 3, p. 1277, 2012.
165
R.D. Johnson, L.C. Chapon, D.D. Khalyavin, P. Manuel, P.G. Radaeli, and C. Martin, “Giant improper
ferroelectricity in the ferroaxial magnetic CaMn7O12”, Phys. Rev. Lett. vol. 108, p. 067201 (2012).

ISAF3-F2-3 _____________________________________________________________________________________________________________________

Electromagnon in the pyroelectric ferrimagnet ε-Fe2O3
Filip Kadlec1, Christelle Kadlec1 , Veronica Goian1, Martí Gich2, Martin Kempa1, Stéphane Rols3,
Maxim Savinov1, Jan Prokleška4, Milan Orlita5 and Stanislav Kamba1
1

Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8,
Czech Republic
2
Institut de Ciència de Materials de Barcelona, Campus UAB, 08193, Bellaterra, Spain
3
Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
4
Faculty of Mathematics and Physics, Charles Univ., Ke Karlovu 5, 121 16 Prague 2, Czech Rep.
5
Grenoble High Magnetic Field Lab, CNRS - 25, avenue des Martyrs, Grenoble Cedex 9, France
Email: kadlecf@fzu.cz

Spin waves excited in crystals by the electric component of electromagnetic radiation are called
electromagnons (EMs), in contrast to magnons, which are linked to the magnetic component. The
EMs can be detected in the far-infared (IR) permittivity spectra; typically, a transfer of dielectricstrength from phonons to EMs upon temperature or magnetic field change is observed166. EMs are
known from multiferroics whose ferroelectric polarization is induced by a spin order.
We report a discovery of an EM in the far-IR spectra of ε-Fe2O3 nanograin ceramics, appearing
below 100 K. ε-Fe2O3 is a less known phase of iron oxide with the space group Pna21, stable onlyin the form of nanoparticles with a size of about 30 nm (see Fig. 1). It is a charge transfer insulator,
exhibiting, at room temperature, a collinear spin structure and a record value167 of the coercive field,
Hc ≃20 kOe. Below 110 K, its ferrimagnetic structure becomes incommensurately modulated. We
have performed temperature-dependent IR reflectivity measurements, which revealed a transfer ofphonon strength to the EM peak emerging near 10 meV (see Fig. 1). Terahertz time-domain
spectroscopy shows a temperature- and magnetic-field-dependent ferromagnetic resonance near
0.5 meV and reveals that the EM peak is sensitive to the external magnetic field. Inelastic neutron
scattering data (see Fig. 1) show that the peak scattering frequency corresponds to a magnon fromthe Brillouin zone boundary168.
Our dielectric impedance measurements
show that the spontaneous polarization of
ε-Fe2O3, which has a non-centrosymmetriclattice, cannot be switched by electric field.
Thus, the compound is pyroelectric and it
does not belong to classical multiferroics;
the data show that the existence of EMs is
not limited to spin-induced ferroelectrics.
We suggest that at low temperatures, the Fig. 42: Left: temperature-dependent far-IR reflectivity
Dzyaloshinskii-Moriya
interactionis (lines) and data from THz transmission spectroscopy
activated, tilts the spins and activates the (symbols). Right: Inelastic neutron scattering map of thepowdered sample (pictured in the inset). The framed
EM via magnetostriction.
area marks the mixed magnon-EM branch.
166
167
168

R. Valdés Aguilar & al.,“Colossal magnon-phonon coupling in Eu0.75Y0.25MnO3”, Phys.Rev.B, vol.76, 60404(R), 2007
J. Tuček & al., “ε-Fe2O3: An advanced nanomaterial ...”, Chem. Mater. vol. 22, p. 6483-6505, 2010
C. Kadlec & al., “Electromagnon in ferrimagnetic ε-Fe2O3 nanograin ceramics”, submitted to Phys. Rev. Lett.

ISAF3-F2-4 _____________________________________________________________________________________________________________________

Magnetic field enhanced structural instability in almost multiferroic EuTiO3
Z. Guguchia1, H. Keller, J. Köhler2, and A. Bussmann-Holder2
Physik-Institut der Universität Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland
2
Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
1

EuTiO3 undergoes a structural phase transition from cubic to tetragonal at TS=282K [1] which is notaccompanied by any long range magnetic order. However, it is related to the oxygen ocathedra
rotation driven by a zone boundary acoustic mode softening [2]. Here we show that this displacive
second order structural phase transition can be shifted to higher temperatures by the application ofan external magnetic field (ΔTS~4K for µ0H=9T) [3]. This observed field dependence is inagreement with theoretical predictions based on a coupled spin-anharmonic-phonon interaction
model. The observed magnetic field dependence of TS (Figure 1) demonstrates that a strong spinphonon coupling is present in this compound already at high temperatures which suggests that spin
fluctuations are present at these temperatures most likely driven by the oxygen ion octahedral
rotation.

Fig. 1 a) The specific heat of ETO as a function of temperature within a limited temperature regime
around the structural phase transition temperature TS for fields of 0, 3, 7, 9T. For clarity the data areshifted by 2 J/mol-K relative to each other with increasing magnetic field. b) TS as a function of H
as derived from Fig. 1a.
1. A. Bussmann-Holder, J. Köhler, R. K. Kremer, and J. M. Law, Phys. Rev. B 83, 212102(2011).
2. J. L. Bettis, M.-H.Whangbo, J. Köhler, A. Bussmann-Holder, and A. R. Bishop, Phys. Rev.
B 84, 184114 (2011).
3. Guguchia, H Keller, J Köhler and A Bussmann-Holder J. Phys.: Condens. Matter 24,
492201 (2012).

ISAF3-F2-5 _____________________________________________________________________________________________________________________

05:45 pm
Vibrations in Europium Titinate
David. S. Ellis1, Hiroshi Uchiyama1,2, Satoshi Tsutsui1,2, Kunihisa Sugimoto2, Kenichi Kato3, Alfred Q.R. Baron1,2
1
2
Materials Dynamics Laboratory, RIKEN SPring-8 Center,Research and Utilization Division, SPring8/JASRI
3
Structural Materials Science Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo, Japan
60 years ago, divalent europium was formed in an oxide lattice for the first time [1]. The result was EuTiO 3, acompound isostructural to SrTiO3 , with apparently no structural phase transitions down to ~ 108 K. Besides thediscovery of a magnetic ordering below 5 K in the following decade [2], the material had all but disappeared fromthe publications. With the onset of the new millennium, experiments demonstrating coupling between the
dielectric and magnetic states in EuTiO3 [3-4] led to a flurry of theoretical and experimental works showing its
remarkable properties and potential for practical multiferroics and other diverse uses, ranging from magnetic fielddependent polarization rotators to studying the fundamental properties of electrons [5-11] (not an exhaustive list!).
And as it turned out, there is a phase transition, in fact near room temperature [12]. In this talk we review recent
developments in EuTiO3, including our study of its lattice vibrations with inelastic x-ray scattering [13], whichgive a dynamical view of the structural phase transition and ferroelectric properties.
[1] Brous et al, Acta Crystallographica 6 67 (1953)[2] McGuire et al., Journal of Applied Physics 37 981 (1966)[3] Katsufuji and Tokura, Physical Review B (Rapid Com.) 60 15021 (1999)[4] Katsufuji and Takagi, Physical Review B 64 054415 (2001)[5] Fennie and Rabe, Physical Review Letters 97 267602 (2006),[6] Kamba et al, European Physics Letters
80 27002 (2007),[7] Lee et al, Nature, 466 954 (2010),[8] Ryan et al, Nature Communications, 4 1334
(2013),[9] Kim et al., Physical Review Letters 110 027201 (2013),[10] Mechelen et al., PhysicalReview Letters 106 217601 (2011),[11] Rushchanskii et al., Nature Materials 9 649 (2012)[12] Bussmann-Holder et al., Physical Review B 83 212102 (2011)[13] Ellis et al., Physical Review B (Rapid Com.) 86 220301 (2012)
Figure to right : Condensation of soft phonon mode of EuTiO3 into a Bragg reflection as the structural phasetransition is approached from higher temperature (from [13]).

PZT film processing
CLUB C
Tuesday, July 23 2013, 04:30 pm - 06:00 pm
Chair:

Nazanin Bassiri-Gharb
Georgia Institute of Technology

ISAF2-F3-1 _____________________________________________________________________________________________________________________

Solution Chemistry, Substrate, and Processing Effects on
Chemical Homogeneity of PZT Thin Films
Jon F. Ihlefeld,1 Paul G. Kotula,1 Geoff L. Brennecka,1 Christopher T. Shelton,1 Bonnie B.
McKenzie,1 Bryan Gauntt,1 Dara V. Gough,1 Ping Lu,1 and Erik D. Spoerke1
1

Sandia National Laboratories, Albuquerque, New Mexico/USA
Email: jihlefe@sandia.gov

In this presentation we explore the contributing factors toward preparing high-quality chemicallyhomogeneous lead zirconate titanate (PZT) thin films via chemical solution routes. Principle to thisstudy is the selection of an adhesion layer that forms a low energy interface with platinum on
SiO2/Si substrates, resulting in improved dielectric and ferroelectric responses of PbZr0.52Ti0.48O3.
PZT films deposited on substrates with ZnO adhesion layers have 35% and 21% percent
enhancements over traditional titanium adhesion layers in remanent polarization and permittivity,
respectively, with values of 32 µC/cm and 1950 measured. Enhanced responses have been ascribedto films deposited on ZnO-buffered substrates possessing no composition gradients as determinedfrom chemical mapping utilizing quantitative Energy Dispersive Spectroscopy within in a Scanning
Transmission Electron Microscope. Films prepared on traditional substrates possess significant
gradients in the Ti/Zr concentrations. To understand this observation we have explored the effects
of solution chemistry (traditional sol-gel versus chelate), pyrolysis temperature, substrate adhesion
layer, and crystallization anneal heating rate on chemical gradient formation and subsequent
properties in PZT films. In the course of this study, we have found that films prepared on
Pt/ZnO/SiO2/Si substrates possess homogeneous distributions of zirconium and titanium throughthe film thickness regardless of solution chemistry and pyrolysis condition. PZT films prepared onconventional Pt/Ti/SiO2/Si substrates possess enriched concentrations of titanium near the PZT/Pt
interface in all cases. We will show that this chemical gradient is driven by diffusion of titanium
from the adhesion layer through the platinum bottom electrode. Finally, we will show our mostrecent studies investigating the effect of crystallization heating rate within a rapid thermal annealer
on the gradient formation for films prepared on Pt/ZnO/SiO2/Si substrates. Sandia National
Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly
owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National
Nuclear Security Administration under contract DE-AC04-94AL85000.

ISAF2-F3-2 _____________________________________________________________________________________________________________________

PZT-based high coupling with low permittivity thin films
Kiyotaka Wasa１, Tomoaki Matsushima1, Hideaki Adachi2,Toshifumi Matsunaga 2 ,Takahiko Yanagitani3,Takashi Yamamoto4, and Susan Trolier-McKinstry5
1

Micro-Engineering, Kyoto University, Kyoto, Japan
Panasonic Co., Osaka, Japan
3
Nagoya Institute of Technology, Nagoya, Japan
4
The National Defense Academy, Yokosuka, Japan
5
Materials Research Institute and Materials Science and Engineering. Department, Penn State
University, PA. , USA
2

Email:.kiyotaka.wasa@gmail.com

Piezoelectric thin films of high coupling and/or high piezoelectricity with low permittivity are
essential for better piezoelectric thin film MEMS 1. However, high coupling/highpiezoelectric PZT based thin films show high permittivity similar to bulk PZT ceramics.
Most of the PZT based thin films are polycrystalline with domain structure. We have
epitaxially grown single c-domain/single crystal modified PZT based thin films,
xPb(Mn,Nb)O3- (1-x)PZT(PMnN-PZT),2 for fabricating high coupling/high piezoelectric thinfilms with low permittivity.Table 1 shows their dielectric and piezoelectric properties incomparison with recent reported piezoelectric thin films ,3-9. It is seen the single crystal
PMnN-PZT thin films at optimum chemical composition exhibit reasonable high couplingwith extra low permittivity which could not be observed in bulk PZT materials. The PMnNPZT thin films exhibit extraordinary large e31,f 2/εwith high Qm. These unique properties
are mainly resulted from the domain free single crystal structure. Present PMnN-PZT thinfilms are applicable for better energy harvesting devices 7 and/or GHz wide band filters9.
The mechanism of the unique dielectric and piezoelectric properties of the single crystal
PMnN-PZT thin films will be discussed.
Table 1. Dielectric and piezoelectric properties of conventional ZnO and PZT-based thin films
Materials
ZnO
AlN
PZT
PMN-PT PMN-PT PMnN-PZT PMnN-PZT
Structure
ε/εo

poly
epi
epi
epi.
10.9 9.5
200
800
500

epi

epi.
100

e31,f (Cm-2)-1.0-1.37 -6.2
e231,f /ε(GPa） 10.3
22.3 20.5

-27
50

Qm
Ref.

20
180
[3] Present [7,9]

[4]

100<
[4]

< 100
[8]

[5]

-10.6
25.4

-12
163

poly
850
-16.9
38
.
[6]

[1] S. Trolier-McKinstry & P. Muralt, J. Electroceram.,vol. 12, pp7-17,2004..
[2] K.Wasa et al., IEEE Trans. UFFC, vol.59,pp.6-13, 2012.
[3] K. Wasa et.al., Appl. Phys. Lett., vol.88, pp.122903, 2006.
[4] S.Trolier-McKinstry et al., IEEE Trans. UFFC.,vol.58pp.1782-1792,2011.
[5] S.H. Baek et al., Science, vol.334, pp.958-961, 2011. [6] T. Zhang et al.,Appl. Phys. Lett., vol..94122909, 2009.
[7]K.Wasa et al.,J. Microelectromechanical Systems, vol.21,pp.451-457 2012. [8] Conventional PZT thin films.
[9] N.Yamauchi et al., Appl. Phys. Lett., vol.94, pp.172903, 2009.

ISAF2-F3-3 _____________________________________________________________________________________________________________________PLD Growth and PFM Study of Self-poled, Mono-crystalline
PZT Thin Films: Control of Polarization Direction by Dopants
and Bottom Electrode
Mahamudu Mtebwa1, Ludwig Feigl1, Nava Setter1
1

Ceramic Laboratory, Swiss Federal Institute of Technology of Lausanne, CH-1015 Lausanne,
Switzerland
Email: mahamudu.mtebwa@epfl.ch

Experimental works have established that self-polarization in thin films is associated with theexistence of built-in field resulting from charge carriers such as oxygen or lead vacancies and hightrap density at the bottom interface, that is, difference in electrical boundary conditions between top
and bottom film interface169. Theoretical works have shown that the built-in field is also associatedwith mismatch between the film and the substrate170. Self-polarization has been studied inpolycrystalline thick films using macroscopic techniques including P-V hysteresis loops and Laser
Intensity Modulation Method (LIMM). In thin films self-polarization was observed by PFM171 but
not systematically investigated.
In this work we report the growth of high quality, fully epitaxial, mono-crystalline Pb (Zr0.5T0.5)O3
thin films with step flow growth mode by PLD. For the first time the study of self-polarization in
doped mono-crystalline PZT thin films using PFM is presented. In addition to electrical boundary
conditions, the direction of polarization is controlled by acceptor and donor dopants. Furthermore
the dependence of self-polarization on film thickness is presented.

a

b

c

Figure 43: A 30nm thick 1% Fe doped Pb(Zr0.5Ti0.5)O3 thin film.
(a) AFM image, (b) PFM amplitude, (c) PFM phase. Fe doped
PZT thin films grow self-poled with polarization pointing
downwards. The rectangular region shows polarization
switching when negatively biased dc voltage is applied on the
AFM tip.

169

V. P. Afanasjev, A. A. Petrov, I. P. Pronin, et al., “Polarization and self-polarization in thin PbZr 1-xTixO3”, J. Appl.
Phys. Condens. Matter, vol. 13, p. 8755-8763, 2001.
170

M. D. Glinchuk, A. N. Morozovska, “Ferroelectric Thin Film self-Polarization Induced by Mismatch Effect”,
Ferroelectics, vol. 317, p.125-133, 2005.
171

C. S. Ganpule, V. Nagarajan, H. Li, et al., Pole of 90° Domains in Lead Zirconate Titanate thin Films, vol. 77, p.292297, 2000.

ISAF2-F3-4 _____________________________________________________________________________________________________________________

Chemical Solution Deposited PZT Thin Films on Silicon Substrates with Thin
Intermediate Buffer Layer
J. P. George1, 2, 4, J. Beeckman1, 4, W. Woestenborghs1, 4, P.F. Smet3, 4, W. Bogaerts2, 4 and
K. Neyts1, 4
1

Department of ELIS, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent, Belgium
Department of INTEC, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent, Belgium
3
Department of Solid State Sciences, Ghent University, Krijgslaan 281, 9000 Gent, Belgium
4Center for Nano- and Biophotonics (NB-Photonics), Ghent University, 9000 Gent, Belgium
2

Email: John.PuthenParampilGeorge@elis.ugent.be
The epitaxial deposition of ferroelectric thin films on silicon is a key technology to develop future
electronic and photonic devices on CMOS fabrication platform. The inter-diffusion of theconstituent elements and the reactions at the Si/thin film interface impose a challenge on theepitaxial growth and limit the application of these films on silicon substrates. Different techniques
have already been proposed and demonstrated to aid the thin film growth with either a seed or anintermediate barrier layer.
PZTIn this work, we show the epitaxial growth of
PZT
Lead zirconate titanate (PZT) thin films on
Buffer layer ~ 8.9 nm
bare silicon substrate with conventional 2methoxy ethanol based chemical solution
Silicondeposition1. We have used a lanthanum oxide
300 nm
400 nm(b)(a)
nitrate intermediate buffer layer to promote
the thin film growth on the silicon substrate.
The influence of intermediate barrier layers as Fig. 44: Cross section (a) and top (b) image of the PZT thinsmall as 2.5 – 10 nm on the crystallization, film deposited on silicon substrate with a buffer layer of 8.9
micro-structural, dielectric, and ferroelectric nm and annealed at 600 ºC.
properties of the PZT thin films have been
investigated in detail. Our experiments show that a buffer layer as thin as 4.4 nm can efficiently
promote the thin film growth with a preferential orientation. The annealing temperature and buffer
layer heat treatment are optimized, to obtain an oriented stoichiometric PZT thin film, with desired
properties. The X-ray diffractogram show a preferential PZT growth along the <100>crystallographic orientation, having single perovskite phase with either tetragonal or rhombohedricgeometry. The SEM top and cross section image of the PZT films grown on silicon substrate show
a nano-columnar crystal growth with polygonal crystal grains (see Fig. 1). The SEM and AFM
measurements indicate the presence of smooth, crack free, uniform layers, with densely packed PZT
crystal grains of size 40 - 100 nm, with an average surface roughness less than 5 nm. The electricalproperties of the film are investigated with electric field dependant polarization (P-E) hysteresis andcapacitance-voltage (C-V) measurements. The PZT film annealed at 525 °C, with a buffer layer of 6
nm shows a dielectric constant of 460, remnant polarization (2Pr) of 18 µC/cm2, and coercive field(Ec) of 80 kV/cm.

---------------------------------------------------------------------------------------------------------------------

1

Chen YN, Wang ZJ “Rapid Microwave Annealing of Amorphous Lead Zirconate Titanate Thin Films Deposited by Sol-Gel Method on
LaNiO3/SiO2/Si Substrates”. J. Am. Ceram. Soc. 96:90-5, 2013.

ISAF2-F3-5 _____________________________________________________________________________________________________________________

Nb doped PZT thin films grown by CSD
N. Chidambaram1, A. Mazzalai1, C. Sandu1, D. Balma1, D. Faralli2, L. Colombo2, M. Fusi2, and P.
Muralt1
1

Laboratoire de Céramique, École Polytechnique Fédérale de Lausanne EPFL, Lausanne,
Switzerland.
2
ST-Microelectronics, Via C. Olivetti, Agrate Brianza, Italy.
Email: nachiappan.chidambaram@epfl.ch

Niobium doping is known to have a beneficial effect on many properties of PZT ceramics.
Substituting Ti or Zr on a B-site by Nb ions, form positive point defects that repel oxygen
vacancies. As a consequence PZT domains move more easily. Nb doped ceramics excel in highpiezoelectric coefficients dij and eij, and high permittivitys. Nb doping is not so well studied with
sol-gel processed PZT thin films. To date, the main interest in Nb doped films was to reduceleakage. Nb doping tends to increase the break-down field, which is of course very interesting for
MEMS applications. In this work, we investigated concentration limits, gradient issues, dielectricand piezoelectric properties of such films.
The concentration limit for pyrochlore free, phase pure perovskite was identified. The {100}texture of the PZT films could be maintained also for the Nb containing films. It is supposed that
this texture results in the best possible piezoelectric performance. The Nb doped films showed aslight tetragonal splitting, indicating that Nb deviates the system rather to tetragonal symmetry thanto rhombohedral symmetry. As it is known that sol-gel processing tends to form Zr/Ti gradients, it
was of interest to know whether Nb forms
gradients as well by being accumulated ahead of
the perovskite growth front in the amorphousmatrix. Such a behavior was indeed observed.
Ferroelectric and piezoelectric behaviors ofdifferent Nb doped films were characterized. The
e31,f measured with a measurement of the direct
effect was smaller than the one of the reverse
effect. It seems that it is difficult to pole Nb
doped films sufficiently well. The results of thefirst series allowed us to fine-tune the CSD
precursor solutions for further improvements. The Fig. 45: Shows the cross section SEM micrograph
PZT film resulting from this optimized process, of Nb doped film grown by CSD. Fully dense
was deeply characterized and compared with microstructure was observed. Inset shows the SEM
standard PZT sol-gel films, showing an increased top view, here as well one could observe phase pure
Nb doped PZT without pyrochlore. Bright spots inpiezoelectric performance and reliability.
the top view SEM are platinum residues from lift
off process.

ISAF Group 2 Posters
Forum Hall
Tuesday, July 23 2013, 01:00 pm - 04:30 pm

ISAF-P2B-1 _____________________________________________________________________________________________________________________

Two-Stage Sintering of Multiferroic PZT-Based Ceramics
Supon Ananta1, Orawan Khamman1, Penphitcha Amonpattaratkit1
1

Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang
Mai, Thailand
Email: suponananta@yahoo.com

Highly dense and pure phase of nanograin ceramics are of current scientific and technologicalinterest, especially for utilization in electromagnetic components in which miniaturization andintegration are essential. In this respect, the processing challenge is to produce dense and pure phaseceramics at low temperature, preferably without any additives and pressure, and with the least
amount of coarsening of the initial microstructure. Recently, the potential of a two-stage sintering
technique for the production of dense and pure phase ceramics with fine grain size has been
demonstrated by our group, especially in the area of electroceramics such as BaTiO3172, PbTiO3,
Pb(Fe1/2Nb1/2)O3, Pb(Mg1/3Nb2/3)O3173 and Zn3Nb2O8174 ceramics. In this work, a two-stage
sintering, which exploits the difference in the kinetics between grain boundary diffusion and grainboundary migration, was further employed to produce pure phase of perovskite multiferroic PZTbased ceramics to high density with fine grain size, by suppressing grain growth in the final stage ofdensification. It was found that this technique also offers an additional advantage as it requires a
substantially lower sintering temperature than conventional sintering.

172

W. Chaisan et al., “Two-stage sintering of barium titanate and resulting characteristics”,
Ferroelectrics., vol. 346, pp. 84-92, 2007.
173
R. Wongmaneerung et al., “Effect of two-stage sintering on phase formation, microstructure anddielectric properties of perovskite PMN ceramics derived from a corundum Mg4Nb2O9 precursor”,
Mater. Chem. Phys., vol. 114, pp. 569-575, 2009.
174
P. Amonpattaratkit et al., “Microstructure and dielectric properties of Zn3Nb2O8 ceramics
prepared by a two-stage sintering method”, Ceram. Inter., 2013, in press.

ISAF-P2B-2 _____________________________________________________________________________________________________________________

Synthesis, Formation and Characterization of Perovskite
Ferroelectric PZT-PZN Powders Derived from a Novel
Zn2Nb34O87 Precursor
Penphitcha Amonpattaratkit, Supon Ananta
Department of Physics and Materials Science, Faculty of Science,
Chiang Mai University, Chiang Mai 50200 Thailand
Email: p.amonpattaratkit@gmail.com
Recently, there have been a great deal of interest in complex perovskite lead zirconate titanate-lead zinc niobate or PZTPZN systems because of their high dielectric, piezoelectric and ferroelectric properties suitable for applications in multilayer

capacitors, sensors and energy harvesting devices.1,2 Moreover, it is well documented that the inhomogeneous
mixing in the conventional solid state reaction process and firing temperature leads to formation of secondary phase (i.e. pyrochlore)
and subsequent deterioration of electrical properties in PZT-PZN ceramics.2,3 In this study, a combination of piezoelectric PZTperovskite phase stabilizers and novel Zn2Nb34O87 B-site precursor is employed for the fabrication of Pb(Zr0.44Ti0.56)O3Pb(Zn0.33Nb0.67)O3 powders. Effects of calcination temperature on phase formation, crystal structure,morphology and microchemical composition of calcined PZT-PZN powders synthesized by a solidstate reaction were carefully examined via a combination of X-ray diffraction (XRD), scanningelectron microscopy (SEM), transmission electron microscopy (TEM), particle size analyzer andenergy-dispersive X-ray (EDX) techniques. This study has demonstrated a successful fabrication ofpure-perovskite phase PZT-PZN powders via a combination of piezoelectric PZT perovskite phasestabilizers and novel Zn2Nb34O87 B-site precursor. Moreover, with increasing calcination temperature, theperovskite phase content, cell parameters, degree of tetragonality, particle size and degree of
agglomeration tend to increase.
________________________________________________
1

E. Fernandez, W.D. Mechtaly, M.Q. Lopez, B. Gnade, E.L. Salguero, P. Shah and H.N. Alshareel, “Synthesis andCharacterization of Pb(Zr0.53,Ti0.47)O3-Pb(Nb1/3,Zn2/3)O3 Thin Film Cantilevers for Energy Harvesting Applications”,
Smart. Mater. Res., vol. 2012 (doi:10.1155/2012/872439).

2

A. Ngamjarurojana, O. Khamman, S. Ananta and R. Yimnirun, “Synthesis, Formation and Characterization of Lead
Zinc Niobate-Lead Zirconate Titanate Powders Via a Rapid Vibro-Milling Method”, J. Electroceram., vol. 21 p. 786790, 2008.

3

N. Vittayakorn, G. Rujijanagul, X. Tan, H. He, M.A. Marquardt and D.P. Cann, “Dielectric Properties andMorphotropic Phase Boundaries in the xPb(Nb1/3,Zn2/3)O3-(1-x)Pb(Zr0.5,Ti0.5)O3 Pseudo-Binary System”, J.
Electroceram., vol. 16 p. 141-149, 2006.

ISAF-P2B-3 _____________________________________________________________________________________________________________________

Influences of PZT Addition on the Phase Formation andMultiferroic Properties of PFN-Based Ceramics
Penphitcha Amonpattaratkit, Supon Ananta
Department of Physics and Materials Science, Faculty of Science,
Chiang Mai University, Chiang Mai 50200 Thailand
Email: p.amonpattaratkit@gmail.com
Recently, many electromagnetic ceramics which are promising multiferroic candidate forvarious electronic applications including transducers, capacitors and magnetoresistive random
access memory have been developed from binary systems containing a combination of relaxor andnormal ferroelectric materials.1 In connection with this, Pb(Fe0.5Nb0.5)O3 or PFN ceramics and their solid solu2
tions are one of the most promising multiferroic materials with a perovskite structure . However, the formation of unwanted phases
especially the pyrochlores are one of the major problems in the preparation of these PFN-based compounds.3 To solve this matter, in
this study, a combination of perovskite stabilizer Pb(Zr0.44Ti0.56)O3 or PZT and a wolframite-type FeNbO4 B-site

precursor was employed for the fabrication of PFN-PZT ceramics. The phase formation, microstructure andmultiferroic properties of ceramics in the (1-x)PFN-xPZT (x = 0.1-0.5) system were investigated byusing a combination of X-ray diffraction (XRD), scanning electron microscopy (SEM), energydispersive X-ray (EDX) analyzer and the multiferroic measurement techniques. Phase-pureperovskite of the PFN-PZT ceramics was obtained. These ceramics exhibit first-order ferroelectricphase transition of typical normal ferroelectrics, where the dielectric response peaks are narrow,
sharp and without frequency dispersion, and the dielectric constant above Curie temperature (TC)can be fitted well by Curie law. With the increase of PZT content, tetragonality value of the PFNPZT ceramics was found to increase slightly accompanied by the variation of cell volume, whilst
the P-E ferroelectric hysteresis loops become narrower accompanied by the decrease of remanentpolarization (Pr) and coercive field (EC).
________________________________________________
1

R. Wongmaneerung, P. Jantaratana, R. Yimnirun, S. Ananta, “Phase Formation and Magnetic Properties of Bismuth
Ferrite–Lead Titanate Multiferroic Composites”, J. Supercond. Nov. Magn., 2013 in press.

2

B. Fang, Y. Shan, K. Tezuka, H. Imoto, “High Curie Temperature Pb(Fe 1/2Nb1/2)O3-Based Ferroelectrics:
0.40Pb(Fe1/2Nb1/2)O3–0.34PbZrO3–0.26PbTiO3”, Phys. Stat. Sol., vol. 202 p. 481-489 , 2005.

3

A. Prasatkhetragarn, “Synthesis and Dielectric Properties of 0.9Pb(Zr1/2Ti1/2)O3-0.1Pb(Fe1/3Nb2/3)O3 Ceramics”,
Ferroelectrics., vol. 416 p. 35-39, 2011.

ISAF-P2B-4 _____________________________________________________________________________________________________________________(001)-Oriented Sol-Gel Epitaxial BiFeO3 Thin Films using StoichiometricPrecursor
Qi Zhang1, Owen Standard1, Hsin-hui Huang1, Nagarajan Valanoor1
1

School of Materials Science and Engineering, The University of New South Wales, Sydney,
New South Wales 2052, Australia
Email: peggy.zhang@unsw.edu.au

Preparation of epitaxial BiFeO3 (BFO) thin film by chemical routes is a challenging process as it isdifficult to control the Bi:Fe stoichiometry precisely. Often the imprecision of the starting chemicalcomposition and the volatilisation of Bi during high-temperature annealing leads to secondary
phases or highly conductive films with very poor leakage resistance. To counter this problem,
excessive Bi is often added to the starting reagents but this can lead to the formation of bismuth richphases as well. Therefore a question to ask is: Can we make epitaxial BFO films by precise control
of precursor chemistry?
This question is answered in this presentation. We demonstrate phase pure epitaxial BFO thin films(ranging from 45 to 100 nm in thickness) prepared on (100) SrTiO3 substrates by a non-aqueous
sol-gel deposition process. The first part of the presentation details the sol-gel chemistry of theprocess used and explains how stoichiometric precursors can be used to obtain high quality films.
Starting solutions consisting of Bi- and Fe-nitrates dissolved in 2-methoxyethanol (2-MOE) solvent
were deposited onto substrates by spin-coating. Fourier transform infrared (FTIR) analysis of the
as-deposited coatings indicated polymerisation type reactions, notably esterification and aldehyde
formation, during drying/gelation. Depending on the drying temperature (50–90°C), resultant films
were either pure polymerised gels or powdery with areas of well-developed crystals. Given that 2MOE is both a solvent for the system and a precursor for polymerisation, gelation versus crystal
formation in the films is explained in terms of a competition between the rate of 2-MOE
evaporation and the rate of 2-MOE gelation.
Phase composition and crystallographic orientation were characterised (for uniform gelated films)
as a function of precursor stoichiometry (stoichiometric/Bi-excess), temperature (450–850°C), andannealing atmosphere (air/oxygen) to determine an optimum synthesis route for the formation ofphase-pure epitaxial BFO films (Fig.1). Square polarization hysteresis loops of optimised films
were obtained at room temperature with a maximum 2Pr of 55 μC/cm2 for the best performing
samples with an obvious domain switching behaviour. The as grown samples show a polydomains
state unlike counterpart films made by pulsed laser deposition. The electromechanical behavior of
the BFO thin films (in terms of thickness, orientations, domain structure and dopant compositions)will be presented in detail as a function of selected processing parameters.
(a)

(b)

(c)

(d)

Fig.46: (a) Ferroelectric hysteresis of BFO/LSMO/STO(100) thin film measured at a frequency of 10 kHz atroom temperature; (b) Out-of-plane PFM and (c) In-plane PFM images of BFO/LSMO/STO(100) thin film
(1 µm×1 µm); (d) TEM diffraction pattern of BFO/STO(100) thin film

Comment [NV1]: Caption does not make sens
Make caption point 10 and bold. Does the sample
not have a bottom electrode?

ISAF-P2B-5 _____________________________________________________________________________________________________________________

Production and characterization of organic polar nanofibers
produced by electrospinning
Ricardo Lima, Tiago Monteiro, Pedro Sá, Etelvina de Matos Gomes, Bernardo Almeida and Dmitry
Isakov.
University of Minho, Center of Physics, Campus de Gualtar, 4710-059 Braga, Portugal
Email: dmitry@fisica.uminho.pt
Electrospinning is a versatile cost-effective bottom-up nanomanufacturing process, allowing for the
fabrication of continuous nanofibers with diameters ranging from a few nanometers up to
micrometers. In the last decade the interest in the electrospinning process and in the application ofelectrospun nanofibers is exponentially growing, due to their potential applicability as active
material in electronic and sensor devices. The unique characteristics of electrospun nanofibers are
their high surface-to-volume ratio, intrinsic 3D topography, biochemical flexibility and thepossibility of obtaining extremely long fibers—all features which are strategically important for aremarkable variety of technological applications. Additionally, functional embedded dopants(included inorganic nanoparticles, carbon nanotubes, light-emitting molecules, cell-directing
proteins, conjugated polymers etc.) may greatly expand the use of electrospun nanofibers. The
recent success in the electrospinning of peptides and polymer-free materials is very encouraging forthe consideration of electrospinning as a bottom-up process for fabrication of various 1D organic
stand-alone nanofibers with strong π―π or h-bonding interactions served as molecularentanglements for the stabilization of the continuous fiber-like structure.
Among the polar materials acting as functional elements in nanoelectronic devices, organic polarmaterials are of special interest due to their attractive multifunctional capacity, making them very
attractive for a broad spectrum of potential applications in various fields such as thermoelectricity,
electromechanics, electro-optics etc. The attractiveness of nanosized polar materials results also
from the strong influence of the dimensionality on device performance and from the possibility oftuning their polar properties by changing the molecular structure.
Here, we present an extended number of polar organic materials that can be successfully
electrospun. The materials under investigation include potassium sodium tartrate, triglycine
sulphate, glycine, DL-alanine, urea, L-cistine and sucrose. All materials are embedded into
electrospun nanofibers (with diameters in range of 200-600 nm) and possess strong dipolar
orientation along the fiber direction which were confirmed by X-ray diffraction measurements.
Aligned arrays of such obtained nanofibers present a mesocrystalline structure with highly
anisotropic responses. The study of polar properties such as ferroelectricity, pyroelectricity,piezoelectricity and optical second harmonic generation are presented and discussed. All nanofibers
reveal an enhancement of polar responses as compared with their bulk counterparts. We proposethat the intrinsic orientation of polar molecules along electrospun nanofibers enhance the observed
cooperative phenomena.

ISAF-P2B-6 _____________________________________________________________________________________________________________________

Dielectric Properties of Ba1-xLaxTiO3 Ceramics Prepared by
Two-Step Sintering Method
Ferroelectric perovskite (ABO3) materials play an important role in modern electronics andelectronic engineering (capacitors, microwave technologies, etc.). Barium titanate (A = Ba, B = Ti)
has a special place in this group of compounds since solid solutions with high electrophysical andferroelectric properties based on it are obtained. Therefore, along with the constant improvement in
the technology of ceramic materials, an important area of modification of electrophysicalcharacteristics of the considered systems is doping by different iso-and heterovalent additives in Aand B-sites, both separately and together. Rare earth elements are found to be more efficient incomparison with other dopant additives. It was determined that the introduction of heterovalentcations into the BaTiO3 lattice in A- and B- sites causes a significant change in its electrophysicalcharacteristics. The purpose of this work was to investigate the structure and ddielectric propertiesof Ba1-xLaxTiO3 ceramics prepared by two-step sintering method.
By means of two-step sintering method Ba1-xLaxTiO3 (х = 0–0.05) ceramics with sub-micron
grain size was obtained. The grain size was 200–400 nm at x = 0.025 and 300–700 nm at x = 0.05.
Phase transition temperature was lowered with the growth of lanthanum concentration at the rate of~25°С/mol%. Despite the small grain size the value of dielectric permittivity of the preparedsamples were increased (εmax ≈ (1.7–2.4)×104 for х = 0.025 and ≈ (3.3–4.7)×104 for х = 0.05) ascompared with large grain materials sintered by standard technique (with grain size > 1 µm).
Dielectric losses were at an acceptable level (tanδ ~ 0.05–0.15).

ISAF-P2B-7 _____________________________________________________________________________________________________________________

Effect of Oxygen Addition in the sputtering Gas on the
Structures and Dielectric Properties of Bi2Zn2/3Nb4/3O7 Thin
Films
M. Saeed Khan1,2, Wei Ren1,2, Peng Shi1,2 and Xiaoqing Wu1,2
1

2Electronic Materials Research Laboratory, Xi’an Jiaotong University, Xi’an, Shaanxi, China
International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an, Shaanxi, China
Email: wren@mail.xjtu.edu.cn, sonykhan_007@yahoo.com

Bi2Zn2/3Nb4/3O7 (BZN) thin films were deposited by RF magnetron sputtering technique onto
Pt/TiO2/SiO2/Si substrates at room temperature, without any intentional heating of substrate, as afunction of Ar/O2 atmosphere. As-deposited thin films were post- annealed at a temperature ≤ 200oC, which is compatible with the printed circuit board (PCB) substrates. The effect of Ar/O2 gas
ratio on structures, surface morphologies, dielectric and electrical properties of thin films werestudied to produce dielectric thin films with suitable characteristics for application as an embedded
capacitor. Surface roughness increased with increasing the concentration of oxygen in Ar/O2 gas
ratio but the deposition rate reduced. Moderate oxygen enrichment is helpful for the stoichiometry
in the BZN films, which reduced the leakage current losses and the concentration of charge carriers
produced from oxygen vacancies. The dielectric properties were improved with varying the Ar/O2
gas ratio from 100/0 to 85/15 but no further significant improvement occurred with further variationof the Ar/O2 gas ratio. The dielectric constant increased with increasing annealing temperature up to
150 oC due to the much stronger establishment of bismuth oxide into the thin film and thendecreases with further increase of temperature due to the Bi migration at high temperature. 200 nmthick BZN thin film deposited under Ar/O2 gas ratio of 85/15 and later post annealed at 150 oC had
a dielectric constant of 60.1 with a very low loss of 0.006, measured at 10 kHz. The leakage current
density was 6.7×10-7 A/cm2 at an applied bias field 400 kV/cm.

ISAF-P2B-8 _____________________________________________________________________________________________________________________

Electrical Activity of Ferroelectric BiomaterialsPřemysl Vaněk1, Zdeňka Kolská2, Jan Petzelt1
1

2

Institute of Physics ASCR, Prague, Czech Republic
J.E. Purkyně University, Ústí nad Labem, Czech Republic
Email: vanek@fzu.cz

It is well known that bone is electrically active under mechanical loading, due to the piezoelectricity
of collagen and the movement of ionic fluids within the bone structure. Electrical potentials inmechanically loaded bone have been linked to the mechanical adaptation of bone in response toloading, leading to the suggestion that the addition of an electrically active component to an implantmaterial may improve healing and adaptation of the surrounding tissue. Recently, interest has
grown in exploiting this phenomenon to develop electrically active ceramics for implantation in
hard tissue, which may induce improved biological responses.
Ferroelectric (i.e. also piezoelectric) ceramics, which produce electrical potentials under stress, havebeen among others studied in order to determine the possible benefits of using electrically active
bioceramics as implant materials. Most of the piezoelectric ceramics proposed for implant use
contain barium titanate (BaTiO3). In vivo and in vitro investigations have indicated that ceramics ofthis kind are biocompatible and induce improved bone formation around implants. Nevertheless, theresults are somewhat ambiguous. In majority of them, a negative charge on the surface is preferred
for cell growth but in some cases a positive charge is preferred.
However, previous studies have not taken into account the fact that the charge at the surface offerroelectrics is always quickly compensated (screened) by the opposite charge from thesurroundings. Kalinin1 showed that the charge at the surface of polarized BaTiO3 (or the
ferroelectric domain) is fully screened by adsorbed charges at room temperature in air, so that the
charge on the surface is opposite to that of the polarization. If a ferroelectric is immersed in a liquid(e.g. tissue fluid) it is obvious that an electric double layer and a diffusion layer are formed at its
surface. The charge distribution in these layers can be characterized in a simplified way by zeta
potential (potential at the „slipping“ plane). The zeta potential and its dependence on pH were
frequently measured on colloidal ferroelectric BaTiO3 particles because the zeta potential is crucial
for the stability of colloidal suspensions. However, the dependence of zeta potential on the polarityof the surface of poled ferroelectrics has not been measured until now. Therefore it is not clear if the
spontaneous polarization in ferroelectrics can really have any influence on their bioactive behavior.
We shall measure the zeta potential in dependence of the surface polarity and pH on poled single
crystalline plates of ferroelectric LiNbO3 and BaTiO3. LiNbO3 will be used because of its goodstability of polarization, BaTiO3 because of its known biocompatibility. The zeta potential will be
determined by measurement of streaming potential with an electrolyte flowing in the gap between
two parallel ferroelectric plates.
______________________
1

S.V. Kalinin and D.A. Bonnell, “Local potential and polarization screening on ferroelectric surfaces”, Phys. Rev. B,
vol. 63, p. 125411-1-13, 2001.

ISAF-P2B-9 _____________________________________________________________________________________________________________________

Effect of Nb substitution on (Pb,Ba)ZrO3 ceramics
Bárbara Fraygola1,2, Ulises Salazar3, Alberto Biancoli1, Dragan Damjanovic1 and Nava Setter1
1

École Polytechnique Fédérale de Lausanne, Material Institute, Ceramic Laboratory LC, Lausanne,
Switzerland.
2
Universidade Federal de São Carlos, Departamento de Física, Grupo de Cerâmicas Ferroelétricas,
São Carlos –SP - Brazil
3
Univeridad Autónoma de Puebla, Instituto de Física de la Benemérita, México.
Email: barbara.fraygola@epfl.ch

2

Polarization ( C/cm )Lead zirconate, PbZrO3, is the first antiferroelectric identified and one end member of the highly
useful solid-solution series PbZrO3–PbTiO3. At room temperature PZ is antiferroelectric but atelevated temperatures, it is ferroelectric over a very narrow temperature range (230–233 ◦C). The
ferroelectric phase can become dominant by
partial replacement of Zr+4 ions for Ti+4 ions20
PBZ
PBZ+0.5Nb(PZT ceramics) and also by partially replacing
15
2+
2+
Pb by Ba ions (PBZ). The temperature range
10of this intermediate phase increases with5
increased Ba concentration.
0-5
The electromechanical properties of ferroelectric-10materials can be modified by doping in order to-15
meet the requirements for various applications.
-20
This is well known in PZT ceramics, in which
-30
-20
-10
0
10
20
30
even a very small amount of the dopant element
Electric Field (kV/cm)
affects macroscopic properties and makes theferroelectric hard or soft. We investigate whether Fig. 47: Ferroelectric Hysteresis loops for pure andhard and soft behavior occurs also due to doping 0.5% Nb doped (Pb,Ba)ZrO3 ceramics.
of PBZ, which,to the best of our knowledge, has
not been studied before.

Pb0.77Ba0.23ZrO3 ceramics with 1-mol%-PbO-excess have been prepared with various Nb-dopant
concentrations between 0.05 and 2 mol% by the mixed-oxide route. The densification behavior andthe microstructural development, as well as ferroelectric, dielectric, and piezoelectric properties
were measured and analyzed. The phase analysis of the sintered solid solutions revealed singlephase perovskite for all concentrations. The results showed a different relative density and grain
size dependence for samples containing >0.5 mol% additives compared to samples with <0.5 mol%Nb. Nb doping influenced significantly the electrical characteristics. Softening and a very marked
increase in the dielectric and piezoelectric characteristics were obtained for low concentrations of
Nb+5. The influence of the dopants and associated defects on the physical, microstructural andelectrical characteristics was investigated and well correlated.

ISAF-P2B-10 ____________________________________________________________________________________________________________________

Comparative study of synthesis and properties of multiferroic
BiFeO3 nano-objects
X. F. Bai1, I. C. Infante1, C. Bogicevic1, S. Gonzalez2, C. Mathieu2, N. Barrett2, and B. Dkhil1
1

SPMS laboratory, UMR 8580 Ecole Centrale Paris-CNRS, Châtenay-Malabry, France
2
DSM/IRAMIS/SPCSI, CEA-Saclay, Gif-sur-Yvette, France
Email: xiaofei.bai@ecp.fr

Bismuth ferrite (BiFeO3) has received a lot of attention as it is one of the rare multiferroic material
showing simultaneously ferroelectric and antiferromagnetic orders at room temperature.
Remarkably, because of its small band gap (~2.2eV) and good chemical stability, it was recently
demonstrated to have significant photocatalytic and photovoltaic properties which make it a very
interesting material for developing potential photoferroelectric applications in the UV and visible
light range.
This work is devoted to study this multiferroic material at the nanoscale. We will show results on
the synthesis and characterization of nano-objects of BiFeO3. The fabrication of pure and Ca-doped
BiFeO3 nano-objects have been performed using different methods (soft chemical route, sol-gel
synthesis, co-precipitation and hydrothermal process, solid-state reaction) in order to investigate theinfluence of the shape and preparation conditions on the nano-objet properties. These different
routes have been adapted to tune and obtain particles of different morphology and size. Throughstudying the functional properties, the optimized fabrication conditions will be proposed. The
ferroelectric domains and surface chemistry of different BiFeO3-nano-objects have been
investigated using local electron microscopy (SEM, TEM and LEEM) to understand their influenceon functional properties. Their ferroelectric and magnetic properties and first measurements on thephotocatalytic and photovoltaic properties will be presented. We will discuss on the effect of thechemistry, structure and ferroelectric domain arrangement of these nano-objects on theirmacroscopic photoferroelectric properties. Perspectives on future applications of BiFeO3-basedmaterials will be presented.

ISAF-P2B-11 ____________________________________________________________________________________________________________________

Preparation and electrical properties of multilayered BaTi1-xZrxO3 composite ceramics
The study of ABO3-type solid solutions based on perovskite-structured BaTiO3 has so far been of
great interest as it offers the possibility to optimize several electrical properties for the manufactureof a number of devices. Nevertheless, pure BaTiO3 shows large changes in permittivity around thephase transitions temperatures. This characteristic is a problem for many applications and manykinds of dopants have been added to depress and/or broaden the maximum permittivity. Nowadays,
graded ferroelectric ceramics are established as an attractive class of materials in which is possible
to create a gradient of properties that cannot be attained in any homogeneous materials175.. Thus, inthe present work, the preparation and characterization of BaTiO3/BaTi0.95Zr0.05O3/BaTi0.85Zr0.15O3
composite dielectric ceramics is reported. The graded ceramic materials were prepared by powderstacking method and uniaxially pressing process, followed by sintering at 1320oC/2h. A variety ofconcentrations and number of layers were studied. The final density of each sintered specimen wasdetermined by the Archimedes method, showing values above 95% of the BaTiO3’s theoreticaldensity in all cases. The interfaces between the layers were studied by micro-Raman spectroscopy
and scanning electron microscopy. The signals obtained from the interfaces show a ~20µm
diffusion layer between the phases. Grain size of the ceramics was evaluated by the intercept
method on the SEM images. Electrical measurements were carried out with a Solartron SI1260
impedance/gain-phase analyzer over a wide temperature range (25 to 400oC). The temperaturedependence of permittivity curve (1 kHz) shows a flat temperature dependence within the range.
According to the series mixing rules these curves were simulated with the permittivity and thevolume fraction of each phase. A good correlation with the experimental data was observed and thecomposites permittivity decrease smoothly to minimum value of each phase. The dielectric spectraof the composites are characterized by dielectric peaks that correspond to the sum of eachferroelectric-to-paraelectric phase transitions in the isolated compositions. In addition, the nature ofthese transitions is seen to change from normal (sharp-like dielectric peak) to diffuse (broad-likedielectric peak). On the other hand, the temperature dependence of permittivity recorded at various
frequencies for the composite show also a change from normal (frequency independent) to relaxor(frequency dependent) phase transition develops.

175

S. Markovic, M. Mitric, N. Cvjeticanin, D. Uskokovic, Preparation and properties of BaTi 1-xSnxO3 multilayred
Ceramics, J. Eur.Ceram. Soc., vol. 27, p. 505-509, 2007.

ISAF-P2B-12 ____________________________________________________________________________________________________________________

Fabrication of lead-free ferroelectric (Na,K)NbO3 thin films by Pulsed
Laser Deposition
Tomohiro Nako1, Natsuki Koyama1, Ichiro Fujii1, Takahiro Wada1
1

Department of Materials Chemistry, Ryukoku University, Japan
Email: t12m082@mail.ryukoku.ac.jp

Pb-based ferroelectric materials have drawbacks from an environmental standpoint. Therefore,lead-free ferroelectric materials have been attracting attention as environmentally benign
compounds. We fabricated NaNbO3(NN) thin films on (001), (110) and (111) SrTiO3 (STO)
substrates using pulsed laser deposition (PLD).1 It is well known that (Na,K)NbO3(NKN) solid
solution has better ferroelectric properties than NN. In this study, we fabricated (Na1-xKx)NbO3 thinfilms with x=0.1(NKN10), 0.2(NKN20) and 0.3(NKN30) on STO substrate by PLD.
NKN thin films were fabricated using this ceramics target by PLD. We deposited NKN films in
the following conditions: O2 partial pressure of about 225 mTorr and substrate temperature of
850°C. Fabricated NKN thin films had about 1-2-μm thickness. The crystalline structures of thefilms were measured by θ/2θ X-ray diffraction (XRD) analysis. The P-E hysteresis loops wereobserved using a ferroelectric tester.
The NKN films were epitaxially grown on (001), (110) and (111) substrates. Figure 1 shows
XRD patterns of NKN30 films deposited on (001), (110) and (111) STO substrates. The NKN filmon (001) STO had a smooth surface, the film on (110) STO had a striped pattern, and that on (111)
STO had trigonal pyramid-like structures. The P-E hysteresis of (Na,K)NbO3 thin films increased
with increased K content. P-E hysteresis of NKN30 films fabricated on (001), (110) and (111) STO
substrates is shown in Fig. 2. All of the NKN30 films show single hysteresis (ferroelectricity). The
P-E hysteresis of NKN30 film on (111) STO substrate shows a very large hysteresis loop and

111

110

001

Fig.1. XRD patterms of (Na0.7K0.3)NbO3 films
deposited on (001), (110) and (111)SrTiO3
substrates.
remanent polarization Pr of 69 μC/cm2.

Fig.2. P-E hysteresis of (Na0.7K0.3)NbO3
films deposited on (001), (110) and(111)SrTiO3 substraes.

1

S. Yamazoe, H. Sakurai, M. Fukada, H. Adachi, and T. Wada, Appl. Phys. Lett. , 95, 062906(2009).

ISAF-P2B-13 ____________________________________________________________________________________________________________________

Effects of InNbO4 fabrication on perovskite PIN-PMN-PT
Linghang Wang1, Zhuo Xu1
1

Electronic Materials Research Laboratory, Key Laboratory of Ministry of
Education＆International Center for Dielectric Research, Xi'an Jiaotong University, Xi’an 710049,
P. R. China
Email: uswlh@yahoo.com.cn
Due to the superior piezoelectric properties compared to ceramics and thin films, such as its
ultrahigh piezoelectric coefficients (d33>1500pC/N) and electromechanical coupling factors(k33>90), the ferroelectric single crystals are regarded as the promising new materials used forelectroacoustic, hydroacoustic or ultrasonic transduction devices. The relaxor-based ferroelectric
ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals have the better
properties at higher temperature, whose Curie temperature is about 200oC with the piezoelectric
constant d33 about 2000pC/N, as compared with the binary Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT)
single crystals and Pb(In1/2Nb1/2)O3-PbTiO3 (PIN-PT) single crystals for the applications in the hightemperature transduction devices. For PIN-PMN-PT crystal growth, however, the perovskite PINPMN-PT raw materials are very critical. In this paper, we pesented effects of InNbO4 (IN)fabrication on the perovskite PIN-PMN-PT. Excess of In2O3 and annealing on the phases ofsynthesized IN were investigated. The pre-sintered IN and unsintered IN powders on the phases of
PIN-PMN-PT were discussed. The experimental results indicated that excess of In2O3 did not haveinfluences on the phase of IN due to higher chemical activity of In2O3, IN powder with 3% In2O3
excess was in grey because of the reaction, In2O3→In2O, annealing at 850oC could make grey IN
powder into white. It is apparent that unsintered IN could obtain the pyrochlore-free PIN-PMN-PT
rather than pre-sintered IN powders. An improved way for preparing PIN-PMN-PT raw materials isdeveloped.

ISAF-P2B-15 ____________________________________________________________________________________________________________________

Synthesis of Needle-like NaNbO3 Particles by Hydrothermal
Process
Ebru Mensur Alkoy1, Sedat Alkoy2,3, Yağız Özeren2,
1

Faculty of Engineering and Natural Sciences, Maltepe University, Maltepe, Istanbul, Turkey
2
Dept. Materials Sci. & Eng., Gebze Institute of Technology, Gebze, Kocaeli, Turkey
3
ENS Piezodevices Ltd., Gebze, Kocaeli, Turkey
Email: ebrualkoy@maltepe.edu.tr

In recent years, great efforts have been spent on to develop lead-free piezoelectric ceramics, which
exhibits high piezoelectric and ferroelectric properties, due to the restrictions on the use of lead andother hazardous substances. One way to obtain enhanced piezoelectric properties in lead-freepiezoceramics is to fabricate them with grain orientation and crystallographic texture. Potassium
sodium niobate – KNN, [(K,Na)NbO3], is one of the leading lead-free composition that have been
investigated in texture studies in detail.176 However, all of these templated grain growth (TGG)
studies use plate-like sodium niobate – NN, [NaNbO3], templates and align these templates using
tape casting process.
The final objective of our study is to obtain grain oriented and textured KNN fibers that will be usedin the fabrication of KNN based 1-3 piezocomposites. NN templates with needle-like morphology
are required to induce a fiber texture in KNN. NN templates are known to grow with a plate-likemorphology, when synthesized through the molten salt synthesis and topotactical transformation
method. Thus, in this study, sodium niobate (NN) particles were synthesized by hydrothermal
process. Since the aim of this study is to obtain anisometric morphology, various hydrothermal
treatment temperatures and durations, as well as OH and Nb molarity have been investigated.

Fig. 1: SOMS with needle-like morphology (T=150ºC) Fig. 2: NN with cubic morphology (T=160ºC)

The Na8Nb6O19.13H2O phase with needle-like morphology was obtained at 120°C, the Sandia
Octahedral Molecular Sieve (SOMS) morphology started to form at 130ºC and was fully obtained at
150ºC (Fig. 1), whereas the perovskite NaNbO3 particles with cubic morphology was obtained at
176

Saito, Y., H. Takao, T. Tani, T. Nonoyama, K. Takatori, T. Homma, T. Nagaya, M. Nakamura, ―Lead -freepiezoceramics‖, Nature, vol. 432, pp. 84-87, 2004.

160°C (Fig. 2). Needle-like morphology was retained after annealing at 400-800ºC. The results of
the hydrothermal treatment process will be presented in details.

ISAF-P2B-16 ____________________________________________________________________________________________________________________

Grain oriented (K0.5Na0.5)NbO3-based piezoelectric ceramics preparedby reactive template grain growth method
A. Hussain1, T. K. Song1, M. H Kim1 and W. J. Kim2
1

School of Nano & Advanced Materials Engineering, Chanwon National University, Gyeongnam 641-773,
Republic of Korea
2

Department of Physics, Changwon National University, Gyeongnam 641-773, Republic of Korea

Lead-base piezoelectric materials such as Pb(Zr,Ti)O3 (PZT) are widely utilized in electrical devices
because of their excellent properties. However, legislations such as RoHS/WEEE (restriction of hazardous
substances/waste electrical and electronic equipment) demand for the development of lead-free piezoelectricmaterials. Lead-free (K, Na)NbO3 (KNN) perovskite system is currently under study as strong potential
candidate for environmentally benign piezoelectric devices. However, pure KNN ceramics are difficult tosinter by conventional methods, and show inferior properties. To improve the performance of KNN ceramicsystem, different techniques for their fabrication such as spark plasma sintering, screen printing, templated
grain growth, and reactive templated growth have been employed. Among these techniques, the reactive
templated grain growth (RTGG) has proved to be more effective in improving the piezoelectric performance.
In this work, lead-free non-stiochiometric (K0.470Na0.545)(Nb0.55Ta0.45)O3 (KNNT) textured ceramics
were prepared by RTGG method using NaNbO3 (NN) templates. The Plate-like NaNbO3 (NN) templates
were synthesized from bismuth layer-structured Bi2.5Na3.5Nb5O18 (BNN) particles by a topochemical
microcrystal conversion (TMC) method. Using 5 wt% of NN templates, textured KNNT ceramics were
fabricated, and their crystal structure, microstructure, dielectric and piezoelectric properties were comparedwith non-textured KNNT ceramics prepared by a conventional solid state reaction method. The textured
KNNT ceramics exhibited high grain orientation and high dielectric constant. In addition, piezoelectric
properties of textured KNNT ceramics were improved, giving a high piezoelectric coefficient d33 = 390 pC/N
and piezoelectric coupling coefficient kp = 0.60.
Corresponding author: Ali Hussain
E.mail: alihussain_phy@yahoo.com

ISAF-P2B-17 ____________________________________________________________________________________________________________________

0.6(Bi0.85La0.15)FeO3-0.4PbTiO3 Multiferroic Ceramics by Tape
Casting
JIN Guo-xi, BU Shun-dong, Wang Da-Lei, Dai Rui, CHENG Jin-rong
School of Materials Science and Engineering/Shanghai University, Shanghai/China
Email: jrcheng@shu.edu.cn
For meeting the needs of function-structure integration design in ceramics, new shaping
technology should be applied into modern ceramic materials. In this letter, BFPT-based multiferroic
specimens formed by tape casting method were studied. Firstly, 0.6(Bi0.85La0.15)FeO3-0.4PbTiO3
powders were obtained by solid state reaction calcined at 750oC. Then the powders were mixed
with ethanol, polyvinylbutyral(PVB), dibutyl phthalate(DBP)-polyethylene glycol(PEG) and
Triethylolamine(TEA) to form tape casting slurry with viscosity range from 650 to 2700 mPa.s.
Filming and rheological properties of slurry was studied by adjusting the components content. Highquality casting films were obtained when the ratio of DBP-PEG/PVB was 1.5 with 1% TEA in
slurry. Casting films were dried, cut and laminated into disks. The effects of forming process on
densification and dielectric properties were studied via controlling forming pressure. Ceramics
formed by 200MPa with Tc=410 oC, tanδ=2.2%, εr=480 at 1kHz while Pr=5.5μC/cm2 at 20kV/cm
were obtained.

ISAF-P2B-18 ____________________________________________________________________________________________________________________

Controllable Synthesis of Different Bismuth Ferrites by an EDTA-assisted Hydrothermal
Method and Photocatalytic Characterization
Tong Tong, Dengren Jin and Jinrong Cheng*
School of materials science and engineering, Shanghai University, Shanghai 200072, P.R.China*corresponding author: jrcheng@shu.edu.cn

Bismuth ferrites crystallites were synthesized by an EDTA-assisted hydrothermal method using
Fe(NO3)3·9H2O and Bi(NO3)3·5H2O as starting materials with NaOH as the mineralizer. Different
phases of bismuth ferrites including sillenite Bi25FeO40, perovskite BiFeO3 and orthorhombic
Bi2Fe4O9 were obtained respectively in the process of hydrothermal reactions by adjusting theprocess parameters, such as NaOH concentration, reaction temperature and duration time et al. The
analysis revealed that EDTA played an important role in the phase evolution of bismuth ferrites andintensely influenced the morphology of bismuth ferrites powders. The mechanism of forming
different bismuth ferrites in the hydrothermal process was also investigated and discussed.
Moreover, photocatalytic properties of the bismuth ferrites crystallites were explored as well. The
as-prepared powders performed a good degradation effect at visible light region, suggesting theirpromising applications as photocatalysts.
Keywords: Bismuth ferrites; Hydrothermal synthesis; EDTA; Photocatalysis

ISAF-P2B-19 ____________________________________________________________________________________________________________________NANOPARTICLES TRANSPORT IN CERAMIC MATRIXES:A NOVEL APPROACH FOR CERAMIC MATRIX COMPOSITE FABRICATION
Andrey N. Rybyanets, Anastasia A. Naumenko
Institute of Physics, Southern Federal University
Rostov on Don, Russia
arybyantes@gmail.com

Nanoparticles are perfect building blocks offering a wide variety of compositions,structures and properties, ideally suited to designing functional nanomaterials andnanodevices. Nanoparticles can be embedded in various matrixes; however, a major
technological problem is spontaneous aggregation of nanoparticles which, as a result, lose
their unique properties. Recently polymer nano- and microgranules filled with nanoparticles(magnetic, metal, oxides etc.) start widely used as a delivery means of nanosubstances inmedical, biotechnology and chemical applications. Very recently, there was a tendency tofix (immobilize) particles on the surface of spherical polymeric microgranules. Suchcomposite micro-nano systems offer a number of significant advantages. When fixed to asurface or embedded in microgranules, nanoparticles lose their tendency to readily
aggregate but retain their reactivity and, for the most part, their physical properties.
Besides, microgranules are easier to manipulate then nanoparticles. Microgranules, coatedor filled with nanoparticles can be used to produce “homogeneous” disperse systems, suchas sols and aerosols, and fabricate films, coatings or bulk materials.
A novel approaches for fabrication of nano- and microporous piezoceramics as well as ceramic
matrix piezocomposites (CMC’s) are proposed in this work. The technique is based on
nanoparticles transport in ceramic matrixes using polymer nanogranules, coated or filled by avarious chemicals, as a porosifiers at standard ceramics fabrication process. Resulting CMC’s arecomposed by super lattices of closed pores filled or coated by nanoparticles of metals, oxides,
ferromagnetics etc., embedded in piezoceramic matrix. Pilot samples of nano and microporous
ceramics and CMC’s were fabricated using different piezoceramics compositions as a ceramic
matrix. Two types of polymer microgranules were used for a nanoparticles transport: polystyrene
microgranules filled by magnetite nanoparticles and polytetraﬂuoroethylene microgranules coatedby metal nanoparticles. Parent microgranules and nanoparticles as well as resulting CMS’s were
examined using transmission and scanning electron microscopy (TEM and SEM). New family of
nano- and microporous piezoceramics and CMC’s are characterized by a unique spectrum of theelectrophysical properties unachievable for standard PZT ceramic compositions and fabrication
methods, including combination of piezoelectric, magnetic and electrets properties, giant dielectricrelaxation, giant piezoelectric and electrocaloric effects, as well as a possibility of controllable
changes of the main properties within a wide range.

ISAF-P2B-20 ____________________________________________________________________________________________________________________

Synthesis and Electromechanical Investigations of Tb
Substituted Bi4Ti3O12-(BiFeO3)m Aurvillius Phase Thin Films

Ahmad Faraz1, Nitin Deepak1, Tuhin Maity1, Saibal Roy1, Martyn E. Pemble1, 2, Lynette Keeney1
1
Tyndall National Institute, University College Cork, Cork, Ireland2
Department of Chemistry, University College Cork, Cork, Ireland

Email: ahmad.faraz@tyndall.ie
Lead-based piezoelectric materials are the most extensively used materials for piezoelectric andferroelectric applications due to their strong piezoelectric responses1. However, due to toxicologicaland environmental concerns, there is a strong impetus to identify and replace Pb-base materials withnew materials having comparable piezoelectric properties for use as piezoelectric actuators, sensors
and transducers, especially for use at elevated temperatures in applications such as engines2.
Bismuth layer-structured ferroelectric materials in the Aurvillius phase are considered as potential
candidates to replace Pb-base materials with high Curie temperatures (Tc generally over 500C) andfatigue-free switching for memories. These materials are naturally 2-D nanostructured, consisting of(Bi2O2)2+ layers alternating with nABO3 perovskite units, described by the general formula
Bi2O2(An-1BnO3n+1). On increasing the number of perovskite layers (n), the microstructural,
ferroelectric, magnetic and other physical properties can be altered significantly. They also offer thedesirable quality of accommodating various cations in their crystal structure.
In this work we report the synthesis and electromechanical investigations of novel 5-layered Tb
substituted Bi4Ti3O12-(BiFeO3)2 thin films (TbB5FTO)
on La0.7Sr0.3MnO3 electrodes/c-plane sapphire substrates
(a)
(b)
(c)
by chemical solution deposition (CSD). Structural andmorphological analyses confirm that films are single
phase with no additional detectable impurity phases.
Piezoresponseforce microscopy (PFM) was used as acharacterization tool to confirm in-plane and out-ofplane piezoelectric behaviour. Local hysteresis loops
were generated by switching-spectroscopy SS-PFM andinformation on local ferroelectric behavior in thesematerials as a function of temperature is presented.
Magnetic measurements were performed using SQUID(superconducting quantum interference device)magnetometery and the potential of TbB5FTO thinfilms as candidate multiferroics is discussed.

(d)

(e)

177

Fig. 1: Vertical DART PFM micrographs
TbB5TFO films on C- plane (0001) Sapphire
substrate (a) Height response (b) Amp response(c) Phase-1 response (d) Phase-2 response (e)Frequency tracking response
177

Y. Saito, H. Takao1, T. Tani, T. Nonoyama, K. Takatori1, T Homma,, T. Nagaya, M. Nakamura, Lead-freepiezoceramics, nature vol 432 Nov 2004
2

M. Demartin Maeder, D. Damjanovic, N. Setter, Lead Free Piezoelectric Materials J. Electrocer. 13, 385–392, 2004

ISAF-P2B-21 ____________________________________________________________________________________________________________________

Hexagonal Ferrite and Ferroelectric Perovskite Magnetoelectric Composites
Robert C. Pullar*, Marco Medeiros, Dmitry V. Karpinsky and Andrei L. Kholkin
Department of Materials and Ceramic Engineering and CICECO, University of Aveiro,Campus Universitário de Santiago, Aveiro, 3810-193, Portugal*

Presenting author, email: rpullar@ua.pt

There has been a great deal of interest in the possibility of coupling between magnetic and electricalproperties in multiferroic and magnetoelectric (ME) ceramics. Because of the inherent problems inestablishing good magnetic and dielectric/ferroelectric properties in a single multiferroic material,
we are investigating the manufacture of magnetoelectric composite materials consisting of separate
magnetic and dielectric/ferroelectric ceramic components, and potential coupling between suchcomponents at up to microwave (GHz) frequencies. In this paper we will report our investigationsof composites consisting of the ferrites BaM (BaFe12O19), SrM (SrFe12O19), Co2Z (Ba3Co2Fe24O41)
or SrZ (Sr3Co2Fe24O41) combined with the ferroelectrics BT (BaTiO3) or KN (KNbO3). The ferrites
were produced by various methods – sol-gel, citrate combustion and solid state ceramics – and theresults compared. This is first time such composites have been made with the Z ferrites orpotassium niobate perovskites. The synthesis and properties of the composites were investigated by
XRD, SEM, VSM, PFM/MFM and dielectric measurements.

ISAF-P2B-22 ____________________________________________________________________________________________________________________

Study of polar and electrical properties of Hydroxyapatite:
Modeling and data analysis
Anna Bystrova1, Yuri Dekhtyar1, Svitlana Kopyl2, Igor Bdikin2, Vladimir Bystrov3, Alla
Sapronova4 and Andrei Kholkin3
1

Insitite of Biomedical Eng. and Nanotechnology, Riga Technical University, Riga, Latvia
Centre for Mechanical Technology and Automation, University of Aveiro, Aveiro, Portugal
3
Department Materials Eng. and Ceramics & CICECO, University of Aveiro, Aveiro, Portugal
4Bergen Center for Computational Science, Unifob AS, N-5008 Bergen, Norway
2

Email: bystrov@ua.pt
1.
Non-homogeneity of hydroxyapatite (HAP) surface structure was shown by atomic force
microscopy (AFM) with formation of nano-crystals area of ~ 500…1000 nm.
2.
These formations could be connected with HAP polymorphism – two phases (hexagonal andmonoclinic) are co-existed, as was shown by our computational modeling (HyperChem 8.0) andfirst principles LDA calculations. The unit cell parameters are different for these phases, as results
the area´s height on surface of various phases are altered. This alteration could generate variation of
surface potential, which could be registered by Kelvin probe scanning, and must be create the local
change of work function. It is first reason of local electrical and polar HAP surface peculiarities
influenced on osteoblastes attachment and proliferation.
3.
Defects formations (such as oxygen vacancy or hydrogen interstices) change unit cell totalenergy and surface potential. Modeling and first principle calculations show that energychanges/per HAP crystal cell unit are approximately ~ 0.1…0.2 eV for these defects. These changes
coincide with experimentally measured work functions alteration on HAP surface. It must be
second reason for influence of nano-interaction with living cells on the HAP surface.
4.
Such defects could be arisen by hydrogenation processes under hydrogen introducing duringhigh pressure treatment, conjugated with following microwave irradiation. Such insertion could
switch OH dipole orientation and as results change the H-OH ordering along OH-column in HAPstructures and creates non-centrosymmetric polar and piezoelectric local areas on HAP structure
and its surface. This technology was apply now for HAP surface modification and insertion of thenegative electrical charges on the HAP surface layer, that change locally of HAP surface potential(and consequence its polar properties), which is very influenced on the cell´s adhesion andproliferation of these living cell, e.g. osteoblasts. Common cumulative effect from reasons 1 and 2
could be estimated by introducing of nano-interaction’s correlation length, which value ~ 200…500
nm correspond to sizes of specific osteoblast’s filaments (such as cell’s leg/stem) and HAP surface
non-homogeneities area.
5. The experimental data of synchrotron illuminations and registered absorption peaks areinvestigated and compared with computational estimation of surface potential and work functions
changes under formations of various types of such defects for each HAP crystal phases.

ISAF-P2B-23 ____________________________________________________________________________________________________________________

Effect of B2O3 Addition on Dielectric and Ferroelectric
Properties of BiFeO3 Ceramic
Thanatep Phatungthane, Gobwute Rujijanagul
Department of Physics and Materials Science, Faculty of Sciences, Chiangmai University,
Chiangmai, Thailand
Email: rujijanagul@yahoo.com
In the present work, the effect of B2O3 addition on sintering behavior, dielectric andferroelectric properties of BiFeO3 (BFO) ceramics was investigated. These ceramics were preparedsuccessfully by a solid state reaction technique for the first time. Phase formations of the obtained
ceramics were investigated by x-ray diffraction technique (XRD). The morphology of the B2O3
added BFO ceramics was characterized by electron microscopy (SEM). The dielectric andferroelectric properties of the ceramics were also investigated. Pure phase perovskite was observed.
Our work indicates that the ceramics exhibit good dielectric and ferroelectric behavior.

Acknowledgements
This work was supported by The Royal Golden Jubilee Ph.D. Program, The Thailand
Research Fund (TRF), Faculty of Science and Graduate School Chiang Mai University and National
Research University (NRU), Office of the Higher Education Commission (OCHE) Thailand.

ISAF-P2B-24 ____________________________________________________________________________________________________________________

Shift of morphotropic phase boundary in PNZT epitaxial films
processed by sol-gel approach
Qi Yu1, Jing-Feng Li1, Yuanming Liu2, Jiangyu. Li2
1

State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science andEngineering, Tsinghua University, 100084 Beijing, People’s Republic of China.
2
Department of Mechanical Engineering, University of Washington, Seattle, Washington 981952600, United States
Email: jingfeng@mail.tsinghua.edu.cn
Motivated by the miniatured trend on the next-generation electronic devices, Pb(Zr,Ti)O3-based
thin films had been treated as a predominant selection among aspects so far due to theoverwhelming piezoelectric and ferroelectric properties especially for the composition situating at
morphotropic phase boundary (MPB). It has been widely accepted that epitaxial films could enablehigher performance as well as numerous fancy phenomena potentially associated with a closer
structure to real single crystals as well as subtle effects originated from constraint of singlecrystalline substrate. In this study, 2% Nb-doped Pb(Zr, Ti)O3 thin films [abbreviated as “PNZT”]
along a wide composition range were deposited onto SrTiO3 single-crystalline substrates withvarious cutting directions including [100], [110] and [111] through a facile sol-gel route. Based on
X-ray diffraction, Raman spectroscopy, ferroelectric test together with piezoresponse measurement
at nanoscale, deviations of MPB from the critical ratio of Zr/Ti=52/48 in bulks were confirmed in
PNZT epitaxial thin films with [001], [110] and [111] preferred orientations. It was found that the
MPB moved to Ti-rich region in both [110] and [111]-oriented system, while to the opposite Zr-richregion in [001]-oriented ones. Optimum electrical properties could be obtained at the location of theshifted MPB composition. Mapping of domains structure and switching was also carried out onscanning probe microscopy platform, which should be helpful to reveal internal mechanisms of
domain configurations and kinetics in PZT-based epitaxial films with various crystallographic
orientations.

Fig. 1: Nanoscale mapping of piezoresponse phase configuration of PNZT epitaxial films (Zr/Ti=30/70, 001oriented).

ISAF-P2B-25 ____________________________________________________________________________________________________________________

Microstructure and Optical Properties of Er 2O3 - Doped
Potassium Sodium Niobate-Tellurite Glass-ceramics
P. Yongsiri1, and K. Pengpat1,2
1

Department of Physics and Materials Science, Faculty of Science,
Chiang Mai University, Chiang Mai, 50200, Thailand
2
Materials Science Research Center, Faculty of Science, Chiang Mai, 50200, Thailand
Email: kamonpan.p@cmu.ac.th
Ferroelectric glass-ceramics have been extensively studied as they possesses the properties of nonporous glasses as well as ferroelectric crystals, giving rise to materials that have the goodmechanical properties of glass and the electro-optical properties of ferroelectric crystals. In thiswork, ferroelectric potassium sodium niobate [(K0.5Na0.5)NbO3 or KNN] crystals are of interest
because of their distinct electrical properties1 and non-linear optical properties2. Many researchers
have attempted to produce glass-ceramics with the ferroelectric178 KNN phase3-4. The difficult partof preparing this glass type is to crystallize the KNN single phase. The idea of combining potassium
sodium niobate crystals in some selected glasses has therefore been developed and called theincorporation method5. In the present study, KNN crystals were firstly introduced to tellurite baseglasses. Transparent glasses of erbium oxide (Er2O3)-doped KNN-tellurite glasses were thensuccessfully prepared by using the incorporation method. Experiments started with the preparationof KNN powder by simple mixed oxide method using calcination temperature of 900oC for 5 h.
Then, the calcined KNN powder was mixed with TeO2 and 0.5-1 mol% Er2O3 dopant. Each batch
was subsequently melted at 800oC for 15 min in a platinum crucible using an electric furnace. The
quenched glasses were then subjected to heat treatment at various temperatures for 4 h in order toform glass-ceramics with the desired crystal phases. X-ray diffraction (XRD) results showed that
KNN solid solution distributed over the glass-ceramic samples. Scanning electron microscopy(SEM) revealed that nano-crystals of KNN and some secondary crystals precipitated in the glassceramics. Crystal sizes increased with increasing heat treatment temperatures. The optical andphysical properties of the prepared glass-ceramics were measured. The values of refractive index(n) ranged between 1.99 and 2.15, while that of density (ρ) ranged between 4.70-5.18 g/cm3. Energy
band gap from the transmission cut-off wavelength (Eg) was measured as 3.14-3.20 eV.

178

M. Ichiki, L. Zhang, M. Tanaka and R. Maeda, “Electrical properties of piezoelectric sodium-potassium
niobate”, J. Eur. Ceram. Soc., Vol. 24, Issue 6, p. 1693–1697, 2004.

2

A. Aronne, E. Fanelli, P. Pernice, S. Peli, C. Giannetti and G. Ferrini, “Crystallization and second harmonic
generation in potassium–sodium niobiosilicate glasses”, J. Solid State Chem., Vol. 182, p. 2796–2800, 2009.

3

A. Aronne, E. Fanelli, P. Pernice, S. Peli, C. Giannetti and G. Ferrini, “Crystallization and second harmonic
generation in potassium–sodium niobiosilicate glasses”, J. Solid State Chem., Vol. 182, p. 2796–2800, 2009.

4

D. E. Vernacotola, S. Chatlani, J. E. Shelby, “Ferroelectric sodium-potassium-niobium silicate glass ceramics”,
proceedings of the 2000 12th IEEE international symposium on application of ferroelectrics, Vol. 2, p. 829, 2000.

5

P. Yongsiri, S. Eitssayeam, G. Rujijanagul, S. Sirisoonthorn, T. Tunkasiri and K. Pengpat, “Fabrication of transparent
lead-free KNN glass-ceramics by incorporation method”, Nanoscale. Res. Lett., Vol. 7, p. 136, 2012.

ISAF-P2B-26 ____________________________________________________________________________________________________________________

Sputtered Pb(Zr,Ti)O3 piezoelectric films
for MEMS application
Hiroki Kobayashi1, Mitsunori Henmi1, Mitsutaka Hirose1, Isao Kimura1, Takehito Jinbo1,
Koukou Suu1
1
Institute of Semiconductor and Electronics Technologies, ULVAC Inc.,
1220-1 Suyama Susono, Shizuoka, Japan
Email: hiroki2_kobayashi@ulvac.com
One of the difficulties in PZT film deposition by sputtering method is to keep the stability in thelead content which is volatile element and deposition rate with the passage of sputtering time.
Another would be how to obtain higher piezoelectric coefficient e31 of PZT film for highperformance devices such as sensor and actuator. In this work, some key technologies forperovskite oxide thin-film production including production tool technologies, their performances of
sputtering, and improvement of properties of PZT film will be introduced.
A multi-chamber type mass production sputtering systems for electronic devices SME-200E(ULVAC Inc.) equipped with an exclusive sputtering module was used. When insulating PZT film
adhered to the shields of the ground potential, charge-up occurred, the impedance of the systemchanged, plasma was pushed to the center of the chamber, exposure to plasma was enhanced, and asa consequence, Pb content within film reduced. In order to stabilize the status of plasma, weinstalled a stable anode, that is, an anode that avoided charge-up due to the adhesion of insulating
PZT film and maintained the role as an anode [1]. As a result that a stable anode was installed, thechange in the Pb composition was 1.0±0.6% by the evaluation until end of target life (total wafer;
400 pieces @2 µm thickness PZT). And the change in the deposition rate was 3.8 μm/h±1.4% anduniformity of within wafer was less than ±5% by the evaluation until end of target life. As a resultthat a stable anode was installed, stability of Pb content and deposition rate within film incontinuous sputtering has been confirmed.
PZT films have been deposited on 8inch diameter Pt(111)/TiOX/SiO2/Si substrates. The PZT films
were deposited under Ar/O2 mixed gas atmosphere of 0.5 Pa. Substrate temperature was heated up
to around 580°C. PZT films were deposited with relatively high growth rate about 3.8 μm/h andthese thicknesses was 2.0 μm. PZT film oriented PZT(001)/(100) preferably, and the pyrochlore
phase cannot be detected. We also note that post in-situ treatment [2] has been recently established,aiming to improve crystalline property and piezoelectric coefficient in our PZT films. After in-situ
treatment, piezoelectric coefficient e31 increased up to -19.2 C/m2, which is remarkably improved
compared to e31 of -14.7 C/m2 as deposited. We have established both mass production capability
and advanced process capability for MEMS devices.
[1] United States Patent, US 6,521,105 B2 (2003)[2] Kobayashi et.al in preparation

ISAF-P2B-27 ____________________________________________________________________________________________________________________

Structural, ferroelectric and piezoelectric propertiesof composition spread Bi1-xGaxFeO3 thin films
N. Jaber1, J. Wolfman1, C. Daumont1, B. Négulescu1, A. Ruyter1, G. Feuillard1, J. Fortineau1,
T. Sauvage2, B. Courtois2, C. Autret-Lambert1, F.Gervais1
1
2

GREMAN laboratory, UMR7347 CNRS, Université François Rabelais, Tours, France
CEMHTI laboratory, UPR3079 CNRS, Orléans, France

Email: wolfman@univ-tour.fr

The coexistence in some oxide materials of distinct ferroic orders (ferroelectricity,
ferromagnetism, ferroelasticity) open the way to new multifunctional applications. Among thosematerials, PZT [(PbZrO3)1-x(PbTiO3)x] and PMNPT [(PbMg1/3Nb2/3O3)1-x(PbTiO3)x] solid solutions
exhibit the highest ferroelectric-ferroelastic coupling and are widely used as piezoelectric sensors ormore recently for energy harvesting applications. However lead-based compound are about to bebanished by European RoHS regulation and a lead-free replacement is required. An importantpiezoelectric effect has recently been shown in Bi1-xRexFeO3 (Re : rare earth) thin films solid
solutions1, related with the occurrence of a morphotropic phase boundary (MPB), as it is the casefor PZT and PMNPT. In this work, we report the exploration of Bi1-xGaxFeO3 (BGFO) phase
diagrams. Composition spread epitaxial BGFO thin films were grown by pulsed laser deposition
onto La0.8Sr0.2MnO3 electrodes. Composition gradients were characterized by EDX and RBS whilephase analysis was realized by X-Ray micro-diffraction (XRMD). Impedance spectroscopy,
ferroelectric cycles and XRMD versus temperature were used to identify phase transitions and
MPBs locations in the composition spread films. Cartographies of the effective d33 measured atvarious length scales with PFM (a few nm), laser interferometry (a few m) and XRMD (a few 100m) across composition spread will be presented and compared.

ISAF-P2B-28 ____________________________________________________________________________________________________________________

Magnetoelectric Coupling of Pb(Zr0.52Ti0.48)O3/Pt/CuFe2O4
Multilayer Thin Films
Sung-Ok Hwang1, Chang Young Koo1, You Jeong Eum1, Jungho Ryu2, Hee Young Lee1,*1School of Materials Science and Engineering, Yeungnam University,
Gyeongsan, 712-749, Korea
2
Functional Ceramics Research Group, Korea Institute of Materials Science (KIMS),
Gyeongnam, 641-831, Korea*

Email: hyulee@yu.ac.kr

The multiferroic materials and/or multilayer structure of ferroelectric/ferromagnetic materials canbe used for sensors, memory storage devices, energy harvesting devices and so on due to theirmagnetoelectric(M-E) coupling properties . But single-phase multiferroic materials such as
BFO(BiFeO3) still have shown lower M-E coupling properties than multilayer structured ones.
Therefore, the hybrid structured ferroelectric/magnetic materials have received a great deal ofattention because their high M-E performances, but it’s also still restricted to bulk materials. In thisregards, we have prepared multilayer thin film structure with PZT and Cu-ferrite.
Polycrystalline Pb(Zr0.52Ti0.48)O3(PZT)/Pt/CuFe2O4 multilayer thin films on quarts(or SiO2/Si)
substrate. The film structure is tri-layered type, CuFe2O4 film was deposited by using pulsed laser
deposition (PLD) method. In order to investigate annealing effect on film microstructure,
ferroelectric and ferromagnetic properties of multilayer thin films, CuFe2O4 layer was heat-treatedat various temperatures. For measuring their electrical and magnetoelectric properties, Pt electrodelayer was deposited on the CuFe2O4 layers by sputtering. PZT layers were fabricated by sol-gel
method on Pt interlayer. And Pt top electrodes were also deposited using by sputtering with shadowmask. Structural and microstructural properties of PZT/Pt/CuFe2O4 multilayer thin films wereobserved by XRD and SEM. Ferroelectric and ferromagnetic behaviors of multilayer films were
examined by measuring polarization and magnetization – electric and magnetic field hysteresis.
Magnetoelectric coefficients were calculated by measured magnetoelectric voltages using
magnetoelectric measurement system.
We’ll discuss the annealing effect on ferroelectric and ferromagnetic properties of multilayer
films, and also discuss the M-E coupling properties as a function of annealing temperatures indetail.

ISAF-P2B-29 ____________________________________________________________________________________________________________________

Microstructure and kHz- and GHz- Range Dielectric properties
of Polycrystalline Ba0.5Sr0.5TiO3 Thin Films
Tanja Pečnik1,2, Sebastjan Glinšek3,4, Brigita Kmet1,4, Barbara Malič1,2,4
1Electronic Ceramics Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia
2Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
3
School of Engineering, Brown University, 184 Hope Street, Providence, Rhode Island 02912, USA
4
Centre of Excellence SPACE-SI, Aškerčeva cesta 12, 1000 Ljubljana, Slovenia
Email: tanja.pecnik@ijs.si
The BaxSr1-xTiO3 (x=0–1) solid solution is suitable for tunable microwave applications, such asphase shifters, tunable resonators, etc. Its main advantage is composition-tunable functional
response, i.e., high dielectric permittivity, relatively low dielectric losses and high tunability at
microwave frequencies179. In the case of solution-derived thin films, knowledge and control of the
microstructure-dielectric properties relations is of crucial importance for the integration into
devices. In this contribution we present the processing of Ba0.5Sr0.5TiO3 (BST) thin films on
polycrystalline alumina substrates and the study of the relationships between the microstructure andthe RF- and MW-range dielectric properties in these films.
The 0.25 M solutions were prepared via alkoxides-based route from alkaline earth acetates and Tibutoxide, which were dissolved in the 2-methoxyethanol-acetic acid mixture. The precursor
solutions were spin-coated on the alumina substrates and the as-deposited films were dried at
200 °C, pyrolyzed at 350 °C and annealed in a rapid thermal annealing furnace at 900 °C. The
deposition-annealing steps were repeated several times to achieve the final thickness of the films.
According to the XRD analysis, the films crystallize in the randomly oriented perovskite phase. The
SEM analysis revealed uniform in-plane microstructures, with grains of a few 10 nm and about 100
nm in 170 nm- and 500 nm- thick films, respectively.
For the RF-range dielectric characterization the planar capacitor structures were deposited using thelift-off photolithography, while the split-post dielectric resonators were used for MW
measurements. The about 170 nm thick films reached the values of the dielectric permittivity,
dielectric losses and tunability (ε0V/ε40V) of 994, 0.01 and 1.63, measured at 100 kHz. The dielectric
properties of the films with different thicknesses, from about 100 nm to 600 nm, andmicrostructures, will be presented in the contribution.

179

M. J. Lancaster, “Thin-film ferroelectric microwave devices”, Supercond. Sci. Technol, vol. 11, p. 1323-1334, 1998.

ISAF-P2B-30 ____________________________________________________________________________________________________________________

Effects of Thermal Treatment on the Properties of Zirconium
Doped Barium Titanate Ceramics
Parkpoom Jarupoom1, Anocha Munpakdee2, Sukum Eitssayeam3, Kamonpan Pengpat3,
Pongthep Arkornsakul3, Gobwute Rujijanagul3
1

Department of Industrial Engineering, Faculty of Engineering, Rajamangala University ofTechnology Lanna (RMUTL), Chiang Mai, 50300, Thailand
2
General Science Department, Faculty of Science, Srinakharinwirot University,
Bangkok, 10110, Thailand
3
Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang
Mai, 50200, Thailand
Email: rujijanagul@yahoo.com
In this work, zirconium doped barium titanate ceramics were prepared via a solid state technique.
After sintering at 1,450 C for 2h, the ceramics were annealed at 1,200 C for 4-16 h. Effects of thethermal treatment on the electrical properties of the ceramics was investigated. An improvement instrain level, ferroelectric properties and piezoelectric coefficient were observed for the 8 h sample.
High strain level and calculated d33 (d*33) of 0.26% and 326 pm/V were also obtained for thissample. The electrical properties were found to correlate with the densification and second phaseformation.
Acknowledgement: The authors would like to thank the Graduate School of Srinakharinwirot
University.

ISAF-P2B-31 ____________________________________________________________________________________________________________________

Electrical Properties of (1-x)BCZT-xBZT
Lead-Free Ceramics
Piewpan Parjansri1, Sukum Eitssayeam1,2
1

Department of Physics and Materials Science, Faculty of Science, Chiang Mai University,
Chiang Mai 50200, Thailand
2
Materials Science Research Center, Faculty of Science, Chiang Mai 50200, Thailand
Email: sukum99@yahoo.com

The aim of this study was to investigate the electrical properties of (1-x)[Ba0.85Ca0.15Zr0.1 Ti0.9]O3x[(BiZn0.5Ti0.5)O3] ceramics system for x = 0.00-0.10. The (1-x)BCZT-xBZT ceramics were
fabricated via solid state reaction technique. The samples were calcined and sintered at 925 ºC for 6
h and 1370 ºC for 3 h, respectively. Phase formation and microstructure of (1-x)BCZT-xBZT
ceramics were studied using an X-ray diffractometer (XRD) and scanning electron microscope(SEM). The physical properties and electrical properties, such as dielectric properties andferroelectric properties were examined. It was found that all the samples show pure perovskite
phase. Grain size and density value were in the range of 2.18-13.30 m and 5.61-5.77 g/cm3,
respectively. The BZT content lead to the change and improved of the dielectric properties ofceramic samples. The dielectric loss values were lower than 0.01 (at 1 kHz) for all samples. The
samples show higher degree of the relaxor like behavior with higher BZT content. In addition, theferroelectric properties were found to depend on the BZT content.

ISAF-P2B-32 ____________________________________________________________________________________________________________________

Relationship of Microstructure and Electrical Properties in SolGel PZT Films
Konstantin Vorotilov1, Alexander Sigov1, Dmitry Seregin1, Yury Podgorny1, Olga Zhigalina2,
Dmitry Khmelenin2
1

Moscow State Technical University of Radioengineering, Electronics and Automation (MIREA),
Moscow, Russia
2
Shubnikov Institute of Crystallography, Russian Academy of Sciences, Moscow, Russia
Email: vorotilov@mirea.ru

Thin PZT films are a prominent material for ferroelectric random access memory (FRAM), MEMS
and other integrated ferroelectric devices180.
Despite the fact that formation of perovskite phase in PZT films prepared by sol-gel techniques has
been the subject of investigation since 1990s, mechanisms of fine crystalline structure formation,
nucleation and growth processes are as yet not fully understood. A comparison between results
reported by different authors is complicated due to various precursor chemistry and preparation
conditions. A comprehensive discussion of different approaches to sol-gel synthesis of PZT films
and nucleation processes was made recently in refs.181,182.
In this work we try to establish main regular trends in formation of fine crystalline structure (withthe use of TEM techniques) of sol-gel PZT thin films annealed at different temperatures and its
effect on electrical properties of the films.
For this purpose in addition to the range of annealing temperatures Ta = 600 - 750°C commonlyused for preparation of sol-gel PZT films, we have studied both the film annealed at low
temperature Ta = 550°C, where perovskite phase has not completely arisen, and one annealed athigh temperature Ta = 900°C, that leads to degradation of multilevel heterostructure as a result ofdiffusion processes.
The structure of the films was studied by transmission electron microscopy (TEM), electron and Xray diffraction; electrical properties were characterized by Sawyer-Tower, capacitance-voltage andcurrent-voltage techniques.
Experimental data on film microstructure (grain size, texture, pyrochlore inclusions, interfaces),changes in structure and composition of the underlying layers are discussed in association withelectrical properties of the films.

180

N. Setter, D. Damjanovic, L. Eng, et al. “Ferroelectric thin films: Review of materials, properties, and applications”,
J. Appl. Phys., vol. 100, p. 051606, 2006.
181
T. Schneller, and R. Waser, “Chemical modifications of Pb(Zr0.3,Ti0.7)O3 precursor solutions and their influence on
the morphological and electrical properties of the resulting thin films”, J. Sol-Gel Sci. Techn., vol. 42, p. 337-352, 2007.
182

A. C. Dippel, T. Schneller, R. Waser, D. Park, and J. Mayer, “Formation sequence of lead platinum interfacial
phases in chemical solution deposition derived Pb(Zr 1-x Ti x)O3 thin films”, Chem. Mater., vol. 22, p. 6209 – 6211,
2010.

ISAF-P2B-33 ____________________________________________________________________________________________________________________

Fabrication and Characterization of PZT-PAni/PVDF Based
Nanocomposite
Oliveira Cibele1, Fuzari Jr, Gilberto de C.3, Sakamoto, Walter2.,Longo Elson1, Zaghete, Maria A.1.
1

Depto de Bioquímica e Tecnologia Química, Instituto de Química/ Univ.
Estadual Paulista – UNESP, Araraquara, S P/ Brasil
2
Depto de Física e Química, Faculdade de Engenharia/ Univ. Estadual Paulista UNESP , Ilha Solteira, S P/Brasil
3
Instituto de Ciências Exatas e da Terra (ICET)/ Univ. Federal de Mato GrossoUFMT/ Barra do Garças, MT – Brasil
Email: zaghete@iq.unesp.br
This work presents the preparation and characterization of PZT ceramic obtained by different
methods. The influence of the synthesis method on the grain size and the morphology are also
object of study. The fabrication and characterization of composite films with 0-3 connectivity,
immersing nanoparticles of PZT into the non-polar poly(vinylidene fluoride) – PVDF as thepolymer matrix were presented. For comparison there are results obtained with composite samples
made of ceramic particles unrecovered and recovered with a conducting polymer. In this sample the
PZT grain was partially covered by PAni, which allowed better distribution of grains in the polymer
matrix avoiding a continuous electrical flux path which does not allow the polarization process ofthe composite sample. The use of this composite as sensor and power converter is an indicative that
it is a good alternative for technological applications. The concept of energy harvesting must be
related to capture the ambient energy and convert it into usable electrical energy without
environment attack i.e., a clean electric energy. Although there are a number of sources of
harvestable ambient energy, such as solar energy and energy from wind, piezoelectric materials arevery interesting due to their ability to convert applied strain energy into usable electric energy1. For
material to be used as a sensor, the relationship between output voltage and input power should be
linear, i.e., the responsivity should remain constant. And regarding the magnitude of responsivity, it
may indicate the quality of the sensor, i.e. the larger the magnitude, more input signal is being
converted into output signal. Samples of PZT/PVDF 30/70 vol.% without and with PAni (PZTPAni/PVDF), previously polarized with a electric field of 5 MV/m for 15 min were characterized. A
analysis of the results allows observing that the composite with polyaniline (PAni) was superior in
all respects in comparison to the other composite. It can easily be observed when comparing the twocomposites 30/70 vol.% that PZT-PAni/PVDF presents better results2.

Fig.1. FE-SEM images of composite

PZT – Pani / PVDF with PZTnanostructures synthesized by(a) Pechini method (b) hydrothermal
microwave method

ISAF-P2B-34 ____________________________________________________________________________________________________________________

Ultrathin BaTiO3/Fe bilayer obtained by Atomic Layer
Deposition for magnetoelectric devices
E. Martinez-Guerra1, Paul P. Horley1
1

Centro de Investigación en Materiales Avanzados (CIMAV S.C.), Chihuahua/Monterrey, 31109
Chihuahua, México.
Email: eduardo.martinez@cimav.edu.mx

Ferroelectric ultrathin BaTiO3 (BTO) films in contact with Fe underlayer have been grown by
Atomic Layer Deposition (ALD) on silicon substrates. In this work Ba-Ti-O films were deposited at
380 °C using Ba cyclopentadienyl precursors and titanium alkoxides. Binary reactions of
Ba(tBu3C5H2)2 and H2O are first studied separately in BaO deposition and are found to result in a
hydration/dehydration cycle, which is strongly influenced by temperature. Self-limiting growth ofamorphous barium titanate films becomes possible when Ti(OMe)4–H2O growth cycles are mixed
as well as possible with Ba( t Bu3C5H2)2–H2O cycles. The formation of Ba(OH)2 is an issue fordeposition of Ba-containing materials with H2O as the oxygen source, and can be severe at low
temperatures. The high growth rates up to 1.0 Å/cycle in this preliminary study were most likely
due to a surface hydroxide contribution to the film growth and thermal decomposition of Ti(OiPr)4.
A strong influence of water purging time was found in growth at 235 °C. The addition of titanium
methoxide–water cycles is effective in stopping a BaO/(Ba(OH)2(H2O)n hydration/dehydration
cycle and thus makes self-limiting growth of Ba–Ti–O films possible. Even though fairly uniform
films could be grown with fixed precursor pulse lengths and sufficiently long H2O purge times, therequired H2O purge time was seen to increase with longer Ba(tBu3C5H2)2 pulses, resulting in nearly
doubled growth rates in the 1–5 second pulse and purge timescale often used in practical ALD. Low
temperature ALD of barium-containing oxides with H2O can thus be both difficult and time
consuming. The situation was improved considerably in higher temperature processing with
Ti(OMe)4 as the titanium source, and self-limiting conditions were found. In general it can beassumed that Ba-Ti-O growth with H2O as the oxygen source becomes easier with lower Ba content
in the film and with as high as possible process temperature, as long as precursor selfdecomposition is avoided. The as-deposited amorphous films are crystallized by post-deposition
annealing at 700 °C. Once the BTO films were crystallized Fe films were prepared by DC-Ion
Sputtering on Si/BTO substrates. Fe films were patterned to form bands by using a shadow mask.
The magnetoelectric effect (ME) was measured with a variation of magnetic field up to 366.07
kA/m and superimposed by a modulation magnetic field of 0.80 kA/m. These magnetic fields were
supplied by an electromagnet with a modula-ted Helmholz coil and the voltage was detected by alock-in amplifier. The ME coefficient was calculated as a variation of the electric field in responseto the applied magnetic field. The effect of the modulation frequency was studied by making ME
measurements at 7 different frequencies from 400 to 1000 Hz. We also study theoretically themultiferroic dynamics in a composite one-dimensional system consisting of BaTiO3 multiferroicallycoupled to an iron chain1. These theoretical results are useful to describe multiferroic interaction at
the interface.

1

Paul P. Horley, “Influence of magnetoelectric coupling on electric field induced magnetization reversal in acomposite unstrained multiferroic chain”, PHYSICAL REVIEW B 85, 054401 (2012).

ISAF-P2B-35 ____________________________________________________________________________________________________________________

Preparation and Energy Storage Properties of Barium
Strontium Titanate Glass-Ceramic Composites via a Sol CoatedMethodQingyuan Hu1, Xiaoyong Wei1, Li Jin1
1

Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education andInternational Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China
Email: huqingyuan@stu.xjtu.edu.cn
The Ba0.6Sr0.4TiO3 based glass-ceramics was successfully fabricated by a sol coated process. In thisprocess, the nanosized Ba0.6Sr0.4TiO3 (abbreviated as BST) powders prepared by sol-gel technology
were dispersed into the MgO-SiO2 glass-sol. The influence of the glass content on the
microstructure, dielectric, and energy storage properties of this BST based glass-ceramics has been
investigated. It is found that the grain size and dielectric constant of such glass-ceramics decreased
with the increasing glass concentration. The average breakdown strength of samples with 4% by
weight of glass additive increased dramatically, which was about 1.5 times higher than pure BST.
The energy storage density was also studied, showing that the BST based glass-ceramics preparedby this sol coated method has a potential for pulse power applications.

ISAF-P2B-36 ____________________________________________________________________________________________________________________

Fabrication and characterization of Pb0.3Sr0.7TiO3 thin films on
stainless steel by the Sol-gel method
Shengli Huang and Jinrong Cheng
School of Materials Science and Engineering, Shanghai University, Shanghai, 200072, China
Email:jrcheng@staff.shu.edu.cn
Abstract：
Pb0.3Sr0.7TiO3 (PST) thin films were deposited on La0.5Sr0.5CoO3 (LSCO)-buffered stainless steel (SS)substrates. Both PST and LSCO thin films were prepared by the sol-gel method. X-ray diffraction
and scanning electron microscopy analysis were used to investigate the crystallinity and surface
morphology of PST thin films. It showed that the crack-free PST thin films presented pure
perovskite phase.The introduction of LSCO had been found to facilitate the formation of (100)textured PST thin films. The dielectric loss and tunability of the PST thin films measured at 1MHz
were 0.018 and 0.32 respectively. The figure of merit (FOM) of PST thin films reached a maximal
value of 18.2. These measured properties indicate that the PST thin film is a promising candidate
for tunability devices.
Keywords: PST thin films, Sol-gel method, Stainless Steel, dielectric properties, tunability

ISAF-P2B-37 ____________________________________________________________________________________________________________________

Synthesis, Microstructural and Electrical Characterization of
ZnO Nanorods Arrays Films with Different Diameter
for
Nanogenerators
Natiara V Madalossi1, Anderson V. Martins, Fernando A. Sigoli2, Ítalo O. Mazali2
1

DMI, Centre for Information Technology Renato Archer - CTI, Campinas/Brazil
Funtional Materials Laboratory, Chemistry Institute / Universidade Estadual de Campinas,
Campinas, SP/Brazil
2

Email: talita.mazon@cti.gov.br
Harvesting of unexploited mechanical energy to power and drive electronic or nanodevices isincreasingly attracting scientific attention.1 Nanoscale materials and nanotechnology could play
important roles in the development of very small volume nanogenerators for self-powder electronics
and nanodevices.2-5 The 1 D ZnO nanostructures have been studied as nanogenarators due toexcellent semiconducting and piezoelectric
8,0x10properties; little toxicity which makes it good for
6,0x10biosafe, biocompatible biomedical applications.
4,0x10In this work, ZnO nanorods were synthesized by
2,0x10chemical bath deposition (CBD).
0,0
Initially, a zinc citrate solution with viscosity-2,0x10
range from 40 to 100 cP was deposited on-4,0x10
Pt/Ti/SiO2/Si substrates by spin coating and heat
-6,0x10treatment at 500 °C by 30 min, 550 °C by 4 h and-8,0x10
0
5
10
15
20
25
700 °C by 2 h to be used as nucleation layer.
Time (s )After that, the nanorods were synthesized by
CBD at 110oC by using zinc acetate and KOH
Fig. 48: ZnO nanorods array film and output
with concentration 0.033 mol L-1 asvoltage.
precursors. The ZnO nanorods were characterized
by XRD and FE-SEM as structural andmicrostructural properties. A series of oriented hexagonal wurtzite ZnO nanorods array films
were grown on Pt/Ti/SiO2/Si substrates. The effect of the nucleation layer on the structure andand diameter of ZnO nanorod array film was analyzed. It was found that the viscosity and heat
treatment of the zinc citrate solution influenced on the diameter and length of the nanorods. A
simple method was used for characterize the output voltage of the nanorods arrays films withdifferent diameter. It was used a device with 8 mm2 and Pt/Ti/SiO2/Si as counter electrode. It wasobserved that the device show a Schottky behavior from I vs V curves. The voltage measured
ranged from 2 mV to 7 mV.
-3

-3

-3

Voltage(V )

-3

-3

-3

-3

-3

1

R. S. Devan, R. A. Patil, J. Lin and Y. Ma, “One-dimensional Metal-Oxide Nanostructures: Recent Developments inSynthesis, Characterization and Applications”, Materials Views, Vol. 22, pp. 3326 -3370, 2012.
2

P. X. Gao, J. H. Song and Z. L. Wang, Advanced Materials, Vol. 19, pp. 67-72, 2007.

3

X. D. Wang, J. H. Song, J. Liu, Z. L. Wang, Science, Vol 316, pp. 102-105, 2007.

4

M. P. Lu, J. Song, M. Y. Lu, M. T. Chen, Y. Gao, L. J. Chen, Z. L. Wang, Nano Letteres, Vol. 9, PP. 1223-1224, 2009.

5

R. Yang, Y. Quin, C. Li, G. Zhu, Z. L. Wang, Nano Letters, Vol. 92, PP. 1201-1205, 2009.

ISAF-P2B-38 ____________________________________________________________________________________________________________________

Multiferroic bismuth ferrite based thin films
G. Yesner, R. Rivera, L. Klein, A. Safari
Glenn Howatt Electroceramic Laboratory, Department of Materials Science and Engineering,Rutgers University, Piscataway, New Jersey
Email: gyesner@eden.rutgers.edu
BiFeO3 (BFO) has stimulated a great interest in recent years for its multiferroic behavior andhigh remnant polarization at room temperature. However, high leakage current resulting fromoxygen vacancies limits the practical applications of BFO films. Therefore, manganese doping isused in order to reduce leakage current. Mn-doped BFO thin films are deposited on Pt/TiO2/SiO2/Si
substrate by a sol gel technique and compared with the un-doped BFO thin films.
A stoichiometric 0.2M BFO precursor solution was prepared followed by a modified sol gel
and spin coating route. The nitrate raw materials were dissolved in a combination of ethylene glycol
and citric acid followed by heating. Layers were deposited on the Pt/TiO2/SiO2/Si substrate anddried on a hot plate. Additional layers were deposited and dried to achieve the desired thickness ofthe film. Finally, the film was annealed using rapid thermal annealing (RTA). A similar process was
carried out to fabricate Mn-doped BFO thin films.
The phase, microstructural, and electrical properties were investigated. The
un-doped
BFO sample (200nm) has unsaturated polarization with 2Ps = 80.4 µC.cm-2, 2Pr = 33.0µC.cm-2, and
2Ec = 400kV.cm-1. For the Mn-doped thin films, the leakage current is reduced by two orders ofmagnitude compared to un-doped samples. It is observed that the remnant polarization increases
from 16.5 to 40µC.cm-2. Processing will be further refined in order to improve electrical properties.

ISAF-P2B-39 ____________________________________________________________________________________________________________________The effect of substitution on the synthesis and dielectric
properties of lead-free KNN ceramics
Ilze Smeltere, Maija Antonova, Anna Kalvane, Maris Livinsh
Institute of Solid State Physics University of Latvia
Email: ilze.smeltere@cfi.lu.lv
Potassium sodium niobate (KNN) solid solutions are considered as possible alternative for the
widely used PZT in some applications. However it is difficult to sinter fully dense KNN ceramic
body what restricts the electrical properties. Therefore modification of ceramics has been
performed: MnO2 was used as a sintering aid and partial B-site ion substitution was made. Obtained
ceramics have a single phase of perovskite structure. The sintering process of alkaline niobates ischaracterized by forming a liquid phase which enhanced density of ceramics. For undoped KNN
ceramic two sharp phase transitions are observed at 190o and about 410oC, corresponding to thephase transitions from orthorhombic to tetragonal (TO-T) and from ferroelectric tetragonal toparaelectric cubic (Tc), respectively. After the partial substitution for Nb+5 both of these phasetransitions are shifted to lower temperatures while increasing dielectric permittivity ε.

ISAF-P2B-40 ____________________________________________________________________________________________________________________

A piezoelectric MEMs process
J. Evans, N. Montross, G. Salazar
Radiant Technologies, Inc., Albuquerque, NM USA
Email: sframboss@ferrodevices.com
Fabricating piezoelectrically-driven micromachines (pMEMs) presents unique problems not facedby the traditional, silicon-based MEMs community. Specifically, the fabrication process for
pMEMs devices requires the deposition of ceramic materials that must then be removed fromcertain areas of the substrate in order to complete the substrate etching and device release. Whenthe bottom electrode is deposited globally followed by the piezoelectric or ferroelectric film, theceramic material is prevented by the bottom electrode from reacting with the substrate surface,leaving a clean surface for deep etching by xenon difluoride or DRIE. The drawback is that thisglobal stack of ceramic material and bottom electrode must be etched aggressively with RIE or ionmilling to remove the unnecessary materials and expose the substrate surface. A less expensive
patterning approach is to use lift-off for the noble metal bottom electrode but this leaves the
majority of the substrate surface exposed to the piezoelectric or ferroelectric ceramic material
during high temperature annealing steps. Difficulty arises in removing the ceramic film from thesurface trench areas and the scribe lanes for those devices that will self-disarticulate. Radiant uses aunique barrier layer in the field to mediate thisissue. The barrier layer is deposited prior to thebottom electrode metal. Wells are etched in thebarrier layer into which the bottom electrode isdeposited. The barrier prevents the formation of
unetchable layers under the piezoelectric or
ferroelectric material where trenches or scribe
lanes are to be placed. The entire stack of
substrate oxide, barrier layer, and ceramic may becleanly removed prior to surface DRIE steps.
The authors will describe the technique andexplain the benefits and difficulties that arise
from the use of this approach in a pMEMs Fig. 49: ENHARVKAAL picowatt energy harvester
prototype.
process flow.

ISAF-P2B-41 ____________________________________________________________________________________________________________________

Dielectric and Ferroelectric Properties of Ba1-xSrxTiO3 Ceramics
Prepared by Multiple Stepped Microwave Sintering
Xusheng Wang, Yang Yu, Xi Yao
Functional Materials Research Laboratory, Tongji University, Shanghai, China
Email: xs-wang@tongji.edu.cn
Microwave sintering technique, compared with conventional sintering technique, has received
considerable attention in ceramic preparation for its short time duration, uniform heating and low
temperature in sintering process, in which the heat is generated internally within the material
through microwave-material interaction instead of originating from external sources. Therefore, thematerial heated uniformly as the microwave-material interaction occurred from the inside to outside
simultaneously rather than energy transfer from the outside to the inside. Here we report our result
on dielectric and ferroelectric properties of Ba1-xSrxTiO3 ceramics prepared by multiple stepped
microwave sintering.
BaTiO3 (99.9%, 100 nm) and SrTiO3 (99.9%, 100 nm) powders were used as raw materials. Ba1xSrxTiO3 powders were prepared by conventional ceramic technique, in which the powders wereprefired at 800℃ for 2 h. Then milled, mixed with PVA and pressed to pellet of 10 mm in diameterand 1 mm in thickness. The schematic diagram of the multiple stepped sintering is sown in Fig.1.
The heating rate is about 10℃/min and the total sintering dwelling time kept to 60 min. The up
temperature of the heating pulse is 1200℃ and low temperature is 800℃. Multiple heating steps
were chosen as 1*60 min, 2*30 min, 3*20 min, 6*10 min and 12*5 min, respectively.
Figure 2 showed the dielectric comparison of the multiple stepped microwave sintering for a typicalcomposition of Ba0.9Sr0.1TiO3 ceramics.

1200C60 min1*60 min20C1200C

30min

30min

800C
2*30 min20C
Figure 1 Schematic diagram of themultiple stepped microwave sintering

Figure 2 Frequency dependence of the dielectric
properties for Ba0.9 Sr0.1 TiO3 ceramics prepared bydifferent steps

ISAF-P2B-42 ____________________________________________________________________________________________________________________

Growth of plate- and tube-shaped langasite-type
Ca3NbGa3Si2O14 piezoelectric crystals and the properties
Yuui Yokota1, Shunsuke Kurosawa1,2, Andrey Medvedev1, Masato Sato3, Kazushige Tota3, Ko
Onodera1,3, Akira Yoshikawa1,2,4
1

2Institure for Materials Research, Tohoku University, Sendai, Japan
New industry creation hatchery center (NICHe) , Tohoku University, Sendai, Japan3
TDK corporation, Nikaho, Japan
4
C&A corporation, Sendai, Japan
Email: yokota@imr.tohoku.ac.jp

The langasite-type piezoelectric single crystals with no phase transition up to the melting points
have been investigated for the applications which can be used at high temperature such as a
combustion sensor. However, the manufacturing cost of the element in the combustion sensor is sohigh that the combustion sensor hasn’t been spread in the market yet. Therefore, we havedeveloped the growth technique of shape-controlled single crystals by the micro-pulling-down (PD) method to reduce the cost of cutting and polishing processes from the bulk crystal183. In
addition, crystal growth and the physical properties of columnar-shaped langasite-type single
crystals were investigated184. In this study, the plate- and tube-shaped Ca3NbGa3Si2O14 [CNGS]
single crystals were grown by the -PD method and their physical properties were investigated.
Starting materials were mixed as a nominal composition, Ca3NbGa3Si2O14, and the mixed powder
was sintered at 1200°C in air. Sintered powder was set in the Pt-Rh crucible with a special-shaped
die at the bottom. For growths of shaped CNGS crystals, the crucibles with square- and tube-shapedies were used, respectively. The crucible was heated by the high-frequency induction coil.
After the crucible and sintered powder in the crucible
reached the melting point of CNGS, the seed crystal
with a-axis crystal orientation along to the growth
direction was touched the bottom of the die(Fig.2(a)). The meniscus on the bottom of the die
gradually expanded with pulling-down the seed
crystal and finally the meniscus covered the full-areaof the bottom of the die (Fig.2(b)). Then the tubeshaped CNGS crystal was grown continuously andthe obtained tube-shaped CNGS crystal is shown in
Fig.2(c). Crystal growth, crystallinity, chemicalcomposition and piezoelectric properties of plate- Fig. 50: Liquid-solid interface (a) when theand tube-shaped CNGS single crystals will be seed crystal touched the bottom of die and (b)reported.
the grown crystal became tube-shape. (c) The
183

as-grown and (d) polished tube-shaped CNGS
crystals.

Y. Yokota, A. Yoshikawa, et.al., “Growth and crystallinity of shaped and multiple sapphire crystals by a micropulling-down method”, J. Cryst. Growth, vol. 318, p. 983-986, 2011.
184

Y. Yokota, A. Yoshikawa, et.al., “Growth of Shape-Controlled Ca3NbGa3Si2O14 and Sr3NbGa3Si2O14 Single Crystals
by Micro-Pulling-Down Method and Their Physical Properties”, Jpn. J. Appl. Phys., vol. 50, 09ND03, 2011.

ISAF-P2B-43 ____________________________________________________________________________________________________________________

Growth and piezoelectric properties of PMN-PT crystal
grown by micro-pulling-down method
Yuui Yokota1, Shunsuke Kurosawa1,2, Andrey Medvedev1, Akira Yoshikawa1,2,3
1

2Institure of Materials Research, Tohoku University, Sendai, Japan
New industry creation hatchery center (NICHe) , Tohoku University, Sendai, Japan3
C&A corporation, Sendai, Japan
Email: yokota@imr.tohoku.ac.jp

The (1-x)PbMg1/3Nb2/3O3-xPbTiO3 [(1-x)PMN-xPT] and (1-x)PbZn1/3Nb2/3O3-xPbTiO3 [(1-x)PZNxPT] crystals with the greatly high dielectric and piezoelectric constants have been expected to be
applied for some high-performance piezoelectric devices such as medical ultrasound imaging
probes, Sonars for underwater communications, high-sensitivity sensors and actuators. However, it
is difficult to grow the single crystals with high uniformity due to the strong segregation in thegrown crystal and complex composition. Therefore, the PMN-PT crystal grown by Bridgemannmethod has the inhomogeneity of chemical compositions in the crystal and it decreases the yieldratio of bulk crystals185. On the other hand, we have developed the shape-controlled piezoelectric
single crystals using the micro-pulling-down(-PD) method186. The crystal growth of the shapecontrolled single crystals by the -PD method can reduce the cost of manufacturing for the
langasite-type single crystals by the decrease of forming process. In this study, the shape-controlled
PMN-PT crystals were grown by the -PD method and the structural and piezoelectric properties of
PMN-PT crystal were evaluated.
Starting materials, PbO, MgO, Nb2O5, TiO2 powders (>3N purity) were mixed as the nominal
composition, 0.65PbMg1/3Nb2/3O3-0.35PbTiO3 and mixed powder was set in the Pt-Rh crucible
which had a 3 mm die at the bottom with 5 holes. The crucible was heated in air by the highfrequency induction coil up to the melting point of PMN-PT. After the powders were molten in the
crucible, the melt came out to the bottom of crucible from the inside. The melt was pulled down by
the Pt wire at 0.03 growth rate.
PMN-PT crystal grown by the -PD method isshown in Fig.1(a).
The crystal had theapproximately 3 mm diameter and 10 mm length.
The diameter of the crystal could be almost
controlled by the 3 mm die of crucible. The
crystal was cut perpendicular to the growth
direction and cut planes were polished (Fig.1(b)).
The center part of the crystal indicated Fig. 51: (a) PMN-PT crystal grown by -PD
transparency and the part are considered to be a method. (b) Cut and polished PMN-PT crystal.
single crystal of PMN-PT. On the other hand, the185

G. Xu, et.al., “Growth and piezoelectric properties of PbMg1/3Nb2/3O3-PbTiO3 crystals by the modified Bridgeman
technique”, Solid State Commun. vol. 120, p. 321-324, 2001.
186

Y. Yokota, A. Yoshikawa, et.al., “ Shaped crystal growth of langasite-type piezoelectric single crystals and their
physical properties”, IEEE Trans. Ultrason. Ferroelectrics. Freq. Contr., vol. 59, p. 1868-1871, 2012.

periphery part had no transparency and the result is due to the evaporation of PbO during crystal
growth. Other crystal growth and properties of grown crystals will be reported.

ISAF-P2B-44 ____________________________________________________________________________________________________________________

Electromechanical displacement of soft/hard PZT bi-layercomposite actuator
Piyalak Ngernchuklin1, C. Jeerapan1, C. Eamchotchawalit 1
1

Materials Innovation, Thailand institute of scientific and technological research (TISTR),
Klong Luang, Pathum Thani, 12120, Thailand
Email: piyalak@tistr.or.th

Lead Zirconate Titanate (PZT) is a well-known piezoelectric material which has been widely used
for transducer, sensor and actuator applications. According to the compositional modifications nearmorphotropic phase boundary, PZTs can be classified into two types, soft PZT and hard PZT,
which are distinguished by the piezoelectric properties. Therefore, the combination effect of thestrain-E-field response of soft/hard PZT composite actuator has been much interested to beobserved. In this study, soft and hard PZT powders were co-pressed into bi-layer disks with various
ratios of soft PZT powder, ranging from 0-100 vol. % (with 10 % increments) and then co-sintering.
Due to the shrinkage rate difference of the two layers, the bi-layer composites with various domeheights were obtained. Moreover, it was shown that the constrained layer either soft PZT or hard
PZT affected to the dome geometry, the strain-E-field response and displacement hysteresis loop.
The electromechanical properties and actuation performance of such bi-layer composite actuators
have been investigated and compared to the soft and hard PZT single layer counterparts.
Keywords : soft PZT, hard PZT, bi-layer composite, actuator

ISAF-P2B-45 ____________________________________________________________________________________________________________________Polyol-based synthesis of high quality lead zirconate titanate
nanostructured thin films
A.Nourmohammadi1, M. Khosravi2, E. Bahremandi3*
1

Department of Nanothechnology, Faculty of Advanced Science and Technologies, University of Isfahan, 8174673441, Isfahan, I. R. Iran2
Department of Nanothechnology, Facuity of Advanced Science and Technologies, University of Isfahan, 81746 73441, Isfahan, I. R. Iran3
Department of Physics, Islamic Azad University, Central Tehran Branch, 14837-69444, Tehran, I.R. IranEmail: abolghasem.nourmohammadi@gmail.com*Email:e.bahremandi@yahoo.com

Nanostructured piezoelectric oxide thin films are suitable two-dimensional materials for the
fabrication of many functional nanodevices such as nanosensors, nanoactuators and nanoelectromechanical systems (NEMS). Lead zirconate titanate (PZT), with the perovskite structure, isa suitable ferroelectric and piezoelectric ceramic material for these applications because it has highspontaneous polarization, dielectric permittivity and piezoelectric coefficients. Therefore, much
effort has already been devoted to improve the quality of PZT thin films.
PZT thin films have already been synthesized by the alkoxide based sol–gel technique using thehydrolysis and condensation of these precursors. However, alkoxide-based PZT sols are almost
unstable because they contain water which lowers their storage time. This prevents longtime storageof the prepared PZT sols. Besides, successful crystallization of the perovskite phase from theannealed alkoxide-based PZT gels requires heat treatment above 650°C which alters the PbO
stoichiometry of the film due to evaporation.
Here, high quality single phase PZT thin films were synthesized via a polyol-based sol–gel process.
It was shown that single perovskite phase PZT thin films can be effectively produced using thepolyol-based PZT sols at 590°C. Polyol-based process is a cost-effective synthesis method for the
fabrication of PZT thin films because chloride precursors of titanium and zirconium are used. In
addition, polyol-based sols are highly stable for a very long time of storage. However, this process
is not extensively investigated, and only one report is available on the successful fabrication of PZT
thin films using this methodxxiii.
The prepared PZT thin films were deposited on Au/SiO2
substrates to fabricate high quality PZT thin films. The
films were built up with multiple spin-coating. Eachcoating step was followed by pyrolysis at 450°C, and the
produced multilayered thin film was annealed at 590°C.
X-ray diffraction, XRD, investigations confirmed
formation of perovskite PZT thin films. Scanningelectron microscopy, SEM, investigations indicated thathigh quality and crack free thin films have been obtained
Fig1.SEM micrograph of a PZT thin film.
(Fig 1).
1

Q.Zou" Novel polyol-derived sol route for fabrication of PZT thin ferroelectric films" Mat. Lett. 40(1999)240-245.

ISAF-P2B-46 ____________________________________________________________________________________________________________________

UV laser-induced poling inhibition in proton exchanged
optical waveguides in lithium niobate
G. Zisis1, M. Manzo2, K. Gallo2, T. Limböck3, E. Soergel3, S. Mailis1
1

Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, U.K.
2
KTH, Applied Physics, SE-106 91 Stockholm, Sweden
3
Institute of Physics, University of Bonn, Wegelerstrasse 8, 53115 Bonn, Germany
Email: soergel@uni-bonn.de

UV laser irradiation of the +z polar face of congruent and MgO doped lithium niobate crystals has
been observed to inhibit ferroelectric domain inversion when the crystal subsequently undergoes
uniform electric field poling at room temperature.187 The UV laser-induced poling inhibition (PI)produces ferroelectric domain structures, which correspond to the UV laser-irradiated tracks andwhich have sufficient depth (a few m) to overlap with waveguide modes.188 A common procedure
for the fabrication of optical waveguides in lithium niobate is proton exchange followed by anannealing step.189 Such waveguides are known as
annealed proton exchanged (APE) waveguides.
Here we report preliminary results, which showthat PI is applicable to APE wave-guides thus
enabling the use of this method for the productionof nonlinear optical waveguide devices. We
therefore utilized a graded-index APE waveguidewith a 1/e-depth of ~ 2.2m.
The existence of PI domains in the APE
waveguides was given by piezoresponse force
microscopy (PFM). Further evidence for thepresence of PI domains in this material systemwere provided by wedge polishing at an obliqueangle (~ 5 degrees) with respect to the surface,followed by brief etching in an HF acid solution.
Wedge polishing offers in addition a detailed Fig. 52: PFM scan of a PI domain obtained on an
view of the depth profile because of a x10 APE waveguide. The sample was wedge-polished.
stretching factor which corresponds to a slope of Image size: 30µm x 30µm
5°.

187

C. L. Sones, A. C. Muir, Y. J. Ying, S. Mailis, R. W. Eason, T. Jungk, A. Hoffmann, E. Soergel, "Precisionnanoscale domain engineering of lithium niobate via UV laser induced inhibition of poling" Appl. Phys. Lett., vol. 92,
072905, 2008.
188

H. Steigerwald, M. Lilienblum, F. von Cube, Y. J. Ying, R. W. Eason, S. Mailis, B. Sturman, E. Soergel, K. Buse,"Origin of UV-induced poling inhibition in lithium niobate crystals" Phys. Rev. B, vol. 82, p. 214105, 2010
189

K. Gallo, C. B. E. Gawith, I. T. Wellington, S. Mailis, R. W. Eason, P. G. R. Smith, D. J. Richardson, and S. M.
Kostritskii, “UV-written channel waveguides in proton-exchanged LiNbO3”, J. Appl. Phys., vol. 101, 14110, 2007

The ability to obtain PI domain structures in proton exchanged waveguides in lithium niobate opens
the way for the utilization of this method for the fabrication of nonlinear, electro-optic and acoustooptic devices in lithium niobate.

ISAF-P2B-47 ____________________________________________________________________________________________________________________

Adsorption Controlled MOCVD Growth of Bismuth Ferrite Thin Films
Nitin Deepak1,2, Lynette Keeney1, Martyn E. Pemble1,2 and Roger W. Whatmore1,2
Tyndall National Institute, University College Cork, ‘Lee Maltings’, Dyke Parade, Cork, Ireland2
Department of Chemistry, University College Cork, Dyke Parade, Cork, Ireland

1

Email: nitin.deepak@tyndall.ie

Bismuth ferrite (BiFeO3) is one of the most widely studied materials due to its interesting
multiferroic properties1. The growth of BiFeO3 by chemical vapour deposition (CVD) proves to bea unique challenge due to the interesting chemistry that happens during the growth. The growth
window regarding temperature, pressure and precursor flow rates for pure BiFeO3 phase is verysmall2, making the controlled growth of BiFeO3 rather difficult.
In this present work we studied the metalorganic CVD (MOCVD) growth of epitaxial BiFeO3 thinfilms on SrTiO3 substrates and found that by carefully controlling the amount of the iron precursor,
Fe(thd)3, where thd = 2,2,6,6 tetramethyl 3,5 heptanedionate, we were able to achieve adsorption
controlled growth. Adsorption controlled growth of BiFeO3 has been previously achieved using
molecular beam epitaxy (MBE)3 but to the best of our knowledge our work represents the firstexample of adsorption controlled growth of BiFeO3 by MOCVD. The effect of the volume of the
precursor injected on the growth of BiFeO3 thin films is studied. Detailed x-ray diffraction (XRD)
and transmission electron microscopy (TEM) studies are presented.

References:
1.

2.

3.

J. Wang, J. B. Neaton, H. Zheng, V. Nagarajan, S. B. Ogale, B. Liu, D. Viehland, V.
Vaithyanathan, D. G. Schlom, U. V. Waghmare, N. A. Spaldin, K. M. Rabe, M. Wuttig and
R. Ramesh, Science 299, 1719 (2003).
S. Y. Yang, F. Zavaliche, L. Mohaddes-Ardabili, V. Vaithyanathan, D. G. Schlom, Y. J.
Lee, Y. H. Chu, M. P. Cruz, Q. Zhan, T. Zhao and R. Ramesh, Applied Physics. Letters 87,
102903 (2005).
J. F. Ihlefeld, A. Kumar, V. Gopalan, D. G. Schlom, Y. B. Chen, X. Q. Pan, T. Heeg, J.
Schubert, X. Ke, P. Schiffer, J. Orenstein, L. W. Martin, Y. H. Chu and R. Ramesh, Applied
Physics Letters 91, 071922 (2007).

ISAF-P2B-48 ____________________________________________________________________________________________________________________

Functional properties of lead-free perovskite(Na0.5Bi0.5TiO3)1-x - (BaTiO3)x thin films

N. D. Scarisoreanu1, F. Craciun2, A. Andrei1, R. Birjega1, C. Galassi3, M. Dinescu1.
1
NILPRP, Bucharest, Romania
2
CNR-Istituto dei Sistemi Complessi, Rome, Italy
3
CNR-ISTEC, Faenza, Italy
Email: dinescum@nipne.ro

The solid solution of (Na0.5Bi0.5TiO3)1-x - (BaTiO3)x is considered to be among the best candidate
lead-free ferroelectric and piezoelectric material for applications as actuators and nonvolatilememory devices. The lead-free perovskite (Na0.5Bi0.5TiO3)1-x - (BaTiO3)x (NBT-BT) has amorphotropic phase boundary (MPB) between the rhombohedral and tetragonal phase (x =0.06 0.07), for which the dielectric, piezoelectric and ferroelectric properties of the material areconsiderably enhanced.
In this study, we have investigated the role of the BT amount on the crystalline structure,
microstructure, dielectric properties, phase transition temperatures and stability limits offerroelectric phases in NBT-BT thin films grown by pulsed laser deposition. Successful growth of
NBT-BT films on platinized silicon substrates has been achieved, the dielectric and piezoelectric
properties of the films being comparable with bulk values. For example, the NBT-BT (x=-0.06) thinfilms show a classic switching behavior, the locally measured value of effective piezoelectriccoefficient d33 eff was 83 pm/V, which is higher than the previously reported values for pure NBT or
several (more used) lead-based thin films. An enhanced stability of ferroelectric phase in thin films
with respect to bulk has been observed and explained by their peculiar microstructure.

ISAF-P2B-49 ____________________________________________________________________________________________________________________

Effects of TiO2 addition on microstructure and dielectric
properties of phase-mixed BST ceramics
Lixin Zhou, Dengren Jin, Jinrong Cheng, Hanting Dong, Chaojun Xie(School of Materials Science and Engineering，Shanghai University，200072)
Abstract: The effects of TiO2 addition on dielectric temperature stability of the phase-mixed BST
ceramics were investigated. These non-uniform phase-mixed BST ceramics were synthesized by amodified solid-state reaction. TiO2 was introduced by the following ways: the TiO2 powders weremixed with BT and ST powders (MixTi), and the TiO2 were proportionally introduced during thecalcining of BT and ST powders respectively (CalTi). The phase structures and microstructures ofthese ceramics were characterized by XRD and SEM, respectively. The compositional gradientswere also examined by EDS and XRD. The Curie peak of MixTi is the lowest and widest, and
MixTi has the best temperature stability, but the normol phase-mixed BST has much higher andmore narrow Curie peak. MixTi also have high tunability more than 30%(1kV/mm, 100kHz). WhenTiO2 was introduced during the calcination of ST, the BST has high and narrow Curie peak, and thetemperature stability becomes worse. The surface SEM micrographs of these ceramics exhibite that,the grain size of MixTi is obviously smaller than the normol phase-mixed BST. In conclusion, theaddition of TiO2 can improve the thermal stability of BST, and sintering routine, such as sintering
temperature and holding duration can change the properties of the Ti-excess BST. MixTi has better
temperature stability, one reason probably is that TiO2 can defer the diffusion of Ba2+ and Sr2+, andtheir compositional gradients is maintained, and the grain size may be another cause. Different
properties by various ways of TiO2 addition may be mainly caused by the region of Ti-excess. Tiexcess region may exist at the grain boundary of BT, while most Ti-excess region may grow in thegrain of ST. The mechanism of TiO2 addition’s effects on the temperatures stability andmicrostructures of the phase-mixed BST were investigated, respectively.
Key words: Ti-excess, (Ba,Sr)TiO3, phase-mixed, dielectric properties, temperature stability,
microwave tunable

ISAF-P2B-50 ____________________________________________________________________________________________________________________RF Magnetron Sputtered Pb(Zr0.52Ti0.48)O3 (PZT) Thin Films on
Flexible Copper Substrates
Joel Walenza-Slabe1, Troy Ansell1, David P. Cann1, and Brady J. Gibbons1
1

Materials Science, School of Mechanical, Industrial, & Manufacturing Engineering, Oregon State
University, Corvallis, OR 97331 (USA)
Email: brady.gibbons@oregonstate.edu

Lead zirconate titanate (PZT) thin films on copper foils were produced using RF magnetron
sputtering and ex situ annealing in controlled atmospheres. The crystallization environment was
best controlled by the combination of a forming gas atmosphere and use of a copper foil envelope,which buffered the oxygen partial pressure during heating and cooling. Films with low loss tangent(<5%) were produced with dielectric constants of ≈500-700. No interfacial layer was detected incross-sectional SEM imaging (see Fig. 1), however there was a second phase observed on thesurface. Spin casting and annealing a PbO sol-gel layer on the surface was found to eliminate thissecond phase. The remanent polarization was 20-35 µC/cm2. The linear Rayleigh behavior,characterizing the sub-switching AC field responseof the domain walls, was determined. An analysisof the hysteresis according to the Preisachformalism is also presented. The irreversible
PZT layer 2
components of the dielectric constant andhysteresis are compared across films of varying
thickness and processing conditions. Finally,
cantilever energy harvesters were fabricated and
PZT layer 1
tested. The device output as a function of
frequency was compared with a model based on theCu
Euler-Bernoulli beam equations. The resonant
frequencies of the cantilevers, 20-40 Hz, were
400 nmfound to match the model well. Modeled peak-topeak voltage was highly dependent on material Figure 53: Cross-sectional image of a 2 layer
parameters but typical values gave an expected PZT thin film deposited by rf magnetron
output of 10-40 mV, which match the observed sputtering on a flexible Cu foil substrate.
values well.

ISAF-P2B-51 ____________________________________________________________________________________________________________________

Pulsed Laser Deposition of Epitaxial Piezoelectric Thin Films
on Flexible Substrates
Ashley D. Mason1, Dylan R. Kearney1, and Brady J. Gibbons1
1

Materials Science, School of Mechanical, Industrial, & Manufacturing Engineering,
Oregon State University, Corvallis, OR 97331 (USA)
Email: masona@engr.orst.edu

Piezoelectrics transduce mechanical strain into a dielectric displacement as well as the converse,
allowing these materials to be used as sensors, actuators, and transducers. Currently lead zirconate
titanate (PZT) is the primary material used in these applications. The strong performance of PZT asa piezoelectric material can be associated with the existence of a morphotropic phase boundary(MPB).
In addition to maintaining compositions close to the MPB, the piezoelectric response of PZT can be
improved by controlling the crystallographic texture of the film. Specifically, {100}-oriented films
are known to exhibit a larger piezoelectric response than {111}-oriented films190. The nucleationand growth process of the film can be manipulated to achieve a desired orientation. On a single
crystal substrate with appropriate lattice match,
PZT almost inevitably grows in the sameorientation as the template191. In this work, Ion
Beam Assisted Deposition (IBAD) of biaxiallytextured MgO on a flexible substrate was utilized
to integrate the enhanced piezoelectric properties
of epitaxial PZT with a technically relevant,
inexpensive, and flexible substrate. Pulsed laser
deposition (PLD) was used to deposit the bottom
electrode and PZT thin films; the complete Fig. 54: Device structure. LNO is deposited on top
device structure is shown in Fig. 1.
of LSMO to increase the thickness of the bottom
electrode prior to the addition of PZT. Evaporated

Additionally, development of an environmentally
Ag is used as a top electrode.
friendly, Pb-free, alternative material withproperties comparable to that of PZT is also
desirable. The same templating and device structure was used to study the properties of epitaxial
Pb-free materials also deposited using PLD. The goal is to understand how crystallographic
orientation impacts the piezoelectric properties of these thin films; based on (Bi0.5Na0.5)TiO3 –(Bi0.5K0.5)TiO3 (BNT-BKT).
The structure and morphology of the deposited films were analyzed with x-ray diffraction (XRD)
and atomic force microscopy (AFM). Piezoelectric properties are characterized at both the macro-

190

X. Du, J. Zheng, U. Belegundu and K. Uchino, “Crystal orientation dependence of piezoelectric properties of leadzirconate titanate near the morphotropic phase boundary,” Applied Physics Letters, vol. 72, pp. 2421-2423, 1998.
191

P. Verardi, F. Craciun, M. Dinescu and C. Gerardi, “Epitaxial Piezoelectric PZT Thin Films Obtained by Pulsed
Laser Deposition,” Thin Solid Films, vol. 318, pp. 265-269, 1998.

and microscopic levels, using double beam laser interferometry and piezoresponse force
microscopy (PFM). Ongoing work will be presented.

ISAF-P2B-52 ____________________________________________________________________________________________________________________THE STRUCTURE AND DIELECTRIC PROPERTIES OF BISMUTH-NICKEL-NIOBIUMOXIDE BASED CERAMICS
Xiukai Cai1, Mingying Lv1, Yun Su2
1

School of Civil Engineering, Shandong Jianzhu University, Fengming Road, Lingang Development Zone,
Ji’nan, 250100, China
2
Department of Physics and Electronic Engineering, Hanshan Normal University, Eastern Bridge, Chaozhou
521041, China

Email: xkcai@sdjzu.edu.cn
A large number of bismuth nickel niobate based dielectric ceramics have been prepared byconventional solid state reaction technique. The structure and dielectric properties of this ternaryoxide system have been investigated by X-ray diffraction analysis and temperature dependences ofdielectric constant and loss factor measured at a wide range of frequencies (100 Hz to 100 KHz).
The structure of compounds around the batch of Bi2O3:NiO:Nb2O5=1:1:1 is cubic pyrochlore, while
departed from this composition there exist at least two phases, including cubic pyrochlore phase,
impurities and some other phases. A low temperature dielectric relaxation peak in mostcompositions can be detected close to the liquid nitrogen temperatures, with the activation energy
being of the order of 0.30 ev. Moreover, there also exists another high temperature dielectric loss
peak for some samples, with the estimated activation energy of approximately 0.70 ev, which is
attributed to the conduction process arisen from the impurities and/or the defect structure phases.

ISAF-P2B-53 ____________________________________________________________________________________________________________________ROLE OF TiO2 AND WO3 IN IMPROVING THE PROCESSING BEHAVIOURS OFBISMUTH-BASED CERAMICS
Yun Su1, Xiukai Cai2, Mingying Lv2
1

Department of Physics and Electronic Engineering, Hanshan Normal University, Eastern Han River Bridge,
Chaozhou 521041, China
2

School of Civil Engineering, Shandong Jianzhu University, Fengming Road, Lingang Development Zone,
Ji’nan, 250100, China

Email: syu@hstc.edu.cn
At least two compositions in the bismuth zinc niobate ternary oxide system, with different ratio of
the amounts of pyrochlore structure phase in the finished ceramics, were chosen as basecomposition used for the TiO2, WO3 adding trials. The processing behavior, especially thesinterability of the bismuth-based ceramics can be dramatically improved with the aids of theaddition of both constitutions. The results of linear shrinkage and relative density measurements andthe direct SEM observation make it clear that the densification process can be easily accomplished,with the sintering temperature lowered and the microstructure of the resultant ceramics finer andmore uniform. At the same time the phase compositions for the TiO2, WO3 doping compositions,i.e. the bismuth zinc niobate cubic pyrochlores, can be maintained. Further electron probe analyses
demonstrate the distribution of Ti and W in the microstructures of ceramics, and a possible doping
mechanism can be suggested.

ISAF-P2B-54 ____________________________________________________________________________________________________________________

Synthesis and Characterization of Piezo-/Ferroelectric
Bi(Zn1/2Ti1/2)O3-PbZrO3-PbTiO3 Solid Solution
Bixia Wang, Yujuan Xie, Nan Zhang, Zuo-Guang Ye
Department of Chemistry and 4D LABS, Simon Fraser University,
Burnaby, BC, V5A 1S6, Canada
Email: zye@sfu.ca
Pb(Zr,Ti)O3 (PZT) ceramics are the most extensively used piezoelectric materials owing to its highCurie temperature (Tc ~ 350°C) and good piezoelectric and electromechanical properties near themorphotropic phase boundary (MPB). Recently, Bi-based perovskite solid solutions such as
PbTiO3-BiFeO3, PbTiO3-BiScO3 and PbTiO3-Bi(Mg,Ti)O3 were investigated due to their large
polarization and multiferroic properties. Bi3+ ion possesses a similar electron configuration (6s2 lonepair) to that of Pb2+, which can enhance polarization in the perovskite lattice. Among the Bi-based
systems, (1-x)Bi(Zn1/2Ti1/2)O3-xPbTiO3 (BZT-PT) with x≤0.4 presents a significant increase in TC(≈700 °C) and tetragonality (c/a=1.11) [1]. Our recent study [2] shows that adding BZT into PZTforms the ternary solid solution: Bi(Zn1/2Ti1/2)O3-PbZrO3 -PbTiO3 [BZT-PZ-PT], in which
enhanced dielectric and ferroelectric and properties are found in the MPB compositions.
In this work, ternary ceramics of the BZT-PZ-PT ternary system are synthesized by solid state
reactions and investigated by x-ray diffraction, dielectric spectroscopy, ferroelectric andpiezoelectric measurements. Studies are focused on three series of compounds, 0.05BZT-0.095PZT,
0.1BZT-0.9PZT and 0.15BZT-0.85PZT, which have the compositions around the MPB withvarying Zr/Ti ratio. It is found that the introduction of BZT into the PZT system makes theparaelectric to ferroelectric phase transition more diffuse, brings the MPB to a lower PT content andenlarges the binary MPB region of PZT. The maximum dielectric constant ε’=1490 is found in the
0.1BZT-0.9PZT series. Enhanced ferroelectric and piezoelectric properties are found in the MPB
region of the 0.15BZT-0.85PZT series, with Pr=35 μC/cm2 and d33=275 pC/N.
On the other hand, single crystals of BZT-PZ-PT have been grown by a high temperature solution
method. The grown crystals exhibit a cubic morphology with light yellow colour. Structure analysis
shows the coexistence of rhombohedral and tetragonal phases in the crystals, which is confirmed by
the domain structure observed by polarized light microscopy, indicating that the composition of thecrystals falls into the MPB region. The birefringence measurement of the rhombohedral phaseindicates a phase transition from ferroelectric to paraelectric phase upon heating. The Curie
temperature is found to be TC = 300˚C by dielectric measurements. A remanent polarization Pr of
24.6 µC/cm2 is displayed with a coercive field Ec of 14.5 kV/cm.
These results show that the BZT-PZ-PT system could be promising piezo-/ferroelectric materials
for high-power electromechanical transducers that can operate in a wide temperature range.
This work is supported by the Office of Naval Research (Grants No. N00014-11-1-0552 andN00014-12-1-1045) and the Natural Science and Engineering Research Council of Canada.
1
2

M. R. Suchomel and P. K. Davies, Appl. Phys. Lett. 86, 262905:1-4 (2005).
Y. Xie, L. Chen, W. Ren and Z.-G. Ye, IEEE Trans. Ultrasonics, Ferroelectrics and Frequency Control 58, 1920 -1927 (2011).

ISAF-P2B-55 ____________________________________________________________________________________________________________________

Identification of LiNb(Ta)O3, LiNb(Ta)3O8 and Li3Nb(Ta)O4
phases in thin films synthesized with different deposition
techniques by means of XRD and Raman spectroscopy
Ausrine Bartasyte1, Valentina Plausinaitiene2, Adulfas Abrutis2, Sandra Stanionyte2, SamuelMargueron3, Pascal Boulet1, T. Kobata4, Yoshiaki Uesu4, Jerome Gleize5
1Department†Institute Jean Lamour, (UMR 7198) CNRS – Lorraine University, Nancy, France
2
University of Vilnius, Dept. of General and Inorganic Chemistry, Vilnius, Lithuania
3
Laboratoire Matériaux Optiques, Photonique et Systèmes, EA 4423, Lorraine University andSupelec, Metz, France
4
Department of Physics, Faculty of Advanced Science and Engineering, Waseda University,
Shinjuku, Tokyo 169-8555, Japan
5LCP-A2MC, Université de Lorraine (EA 4632), F-57078 Metz, France.
Email: ausrine.bartasyte@univ-lorraine.fr
Phase composition of epitaxial/textured LiNb(Ta)O3 films on sapphire substrates, grown by pulsed
laser deposition, atmospheric pressure metal organic chemical vapor deposition and pulsed injection
metal organic chemical vapor deposition was studied by conventional X-ray diffraction techniques.
Raman spectroscopy, being highly sensitive to the symmetry of materials, was used as acountercheck in the compositional analysis. The wavenumbers of Raman modes of LiNb(Ta)3O8
and Li3Nb(Ta)O4 phases were identified from Raman spectra of synthesized powders. It was foundthat standard XRD analysis of phase composition of textured LiNbO3/LiTaO3 films might be notstraightforward and confusing due to close reflection angles of LiNbO3 (LiTaO3) and LiNb3O8(LiTa3O8) phases and different possible origins of asymmetric diffraction peak profiles. Asymmetryof profiles of X-ray diffraction reflections of LiNb(Ta)O3 films was studied in details. Thisasymmetry may have different origins what consequently may result in misleading conclusions
about phase composition of textured LiNb(Ta)O3 films.
Raman spectroscopy, a fast, local and non-destructive probe, was applied for investigation andmapping of phase composition, Li stoichiometry and stresses in LiNbO3 (LiTaO3) films. The
methodology of identification of different phases and extraction of residual stress and precise Li
stoichiometry values from single Raman spectrum of LiNb(Ta)O3 film will be presented. Moreover,this approach might be used for study of phase composition, stress and nonstoichiometry of otheroxide films.

Fig. 55: 2D mapping of
LiNbO3 and LiNb3O8
phase distribution on thesurface of film depositedon R-sapphire by meansof Raman spectroscopy.

ISAF-P2B-56 ____________________________________________________________________________________________________________________

Abnormally Large Dielectric Response in Textured PZT Thin
Films
I.P. Pronin1, S.V. Senkevich1,4, E.Yu. Kaptelov1, O.N. Sergeeva2, A.A. Bogomolov2, D.A. Kiselev3,
M.D. Malinkovich3, V.P. Pronin4
1

Department of Dielectrics & Semiconductors, Ioffe Institute, Saint-Petersburg, Russia
2
Department of Physics, Tver State University, Tver, Russia
3
Department of the Material Science of Semiconductors and Dielectrics, National University of
Science and Technology “MISiS”, Moscow, Russia
4
Department of Physics, Herzen State University, Saint-Petersburg, Russia
In the work, structural and ferroelectric properties of thin PbZr0,54Ti0,46O3 films grown by RFmagnetron sputtering were studied. The films were fabricated in two stages. At first, films were
deposited onto Pt/TiO2/SiO2/Si substrate at low temperature (150oC) and then, ones were
thermally treated at 530-580oC in the conventional furnace to form single perovskite phase. Resultsof X-ray diffraction have shown a well-defined 110-texture film growth. Their microstructure
was consisted of spherulite-type blocks of 10-40 m in size, depending on annealing temperature(Td), Fig.1. The film thickness was varied from 300 to 500 nm. At increasing Td, we have observed
abnormally large dielectric permittivity (k) reached of  2000 at room temperature.
100 U, mV

A

B

0

-100
Е, kV/cm-200

Fig. 56. Spherulite-type microstructure of 500
nm thick PZT film. Scanning electron
microscopy, back-scattering electrons mode,
Ep = 12 keV

0200

Fig. 2. Pyroelectric hysteresis loops
measured in PZT samples having a high(A) and low (B) dielectric constant k

An analysis of the results obtained has revealed the correlation between magnitude of k and size of
spherulite blocks: the more were blocks dimensions, the more were magnitude of k. For moreconvincing were conducted pyroelectric and piezoelectric measurements on the samples differed by
low and high magnitudes of k under applying strong electric fields. To a first approximation,pyroelectric response increased linear with k, Fig.2. Similar behavior was observed at piezoelectriccontact mode measurements. The data obtained are discussed based on S.Wada approach to explain

giant piezoelectric response in ferroelectrics192.

1

S. Wada, T. Muraishi, K.Yokoh, K. Yako, et.al. “Domain Wall Engineering in Lead-Free Ferroelectric Crystals”,
Ferroelectrics, vol. 355, p. 37-49, 2007

ISAF-P2B-57 ____________________________________________________________________________________________________________________

Nanocomposite of magnetic nanoparticles in ferroelectricliquid crystalline hostNatalia Podoliak1, Vladimíra Novotná1, Jana Vejpravová1, Věra Hamplová1, Milada Glogarová1,
Jan Prokleška2, Damian Pociecha3, Ewa Gorecka3
1
Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Prague 8,
Czech Republic
2
Charles University, Faculty of Mathematics and Physics, Ke Karlovu 5, 121 16 Prague 2, Czech
Republic3
Chemistry Department, Warsaw University, Al. Zwirki i Wigury 101, 02-089 Warsaw, Poland
Email: podoliak@fzu.cz
Iron oxides nanoparticles (NPs) are a subject of numerous studies due to their unique superparamagnetic
properties, controlled both by the phase composition and the particle size. When the magnetic NPs size
is less than 50 nm, the single-domain state prevails. In such a case the surface and size effects become
important, resulting in the increase in effective magnetic anisotropy. More attention is now paid to novel
approaches for organizing NPs and different strategies are used for this purpose. Liquid crystals (LC)appear perfect candidates for new composites as they are able to self-organize on the molecular level.
Additionally, nanocomposite of a ferroelectric liquid crystal and magnetic NPs can serve as a new typeof multiferroic systems.
Herein we present a composite system of magnetic NPs in a ferroelectric LC compound denoted 9HL.193
Monodispersive maghemite (-Fe2O3) NPs of size 5.0±0.5 nm have been prepared by thermal
decomposition of iron acetylacetonate in organic media. Oleic acid coatings are chosen to keep the NPs
apart, reducing mainly magnetic dipolar interactions, leading to agglomeration and surface spin effects.
Studied LC compound 9HL, exhibiting the SmA*-SmC* phase sequence, has been mixed with NPs inconcentration up to 8 weight % of Fe (11% Fe2O3). We have found the SmC* phase disappears atconcentration 5.6 % of NPs. For higher concentration the tendency of NPs to cluster together along thesmectic layers has been observed, which is addressed to thesurface energy of the contact between nanoparticles being
lower than the surface energy between the nanoparticles
and liquid crystal. The strong magnetic field of 9 T
influence on the temperature dependence of thepermittivity has been studied for pure 9HL as well as for
1.4 % of NPs in 9HL host. The magnetic properties of NPs
and its composite with 9HL have been studied and foundtypical for a system of superparamagnetic nanoparticles
with inter-particle dipolar interactions and surface spin
disorder. The magnetic response of the composite samples
is somewhat modified due to the reduction of the dipolar
Fig. 1: Phase diagram of Fe O NPs interactions strength between the NPs.
2

3

in 9HL host. Concentration of Fe2O3
is in weight %.
193

F. Giesselmann P. Zugenmaier, I. Dierking, S. T. Lagerwall, B. Stebler, M. Kaspar, V. Hamplova, M. Glogarova,“Smectic-A*–smectic-C* transition in a ferroelectric liquid crystal without smectic layer shrinkage”, Phys. Rev. E, vol.
60, p. 598-602, 1999.

This work is supported by the Czech Science Foundation, projects No P204/11/0723 and No 13-14133S.

ISAF-P2B-58 ____________________________________________________________________________________________________________________(Ag,Li)NbO3 thin films fabricated on (001), (110), and (111)SrTiO3 substrates
by pulsed laser deposition
Yu Yamamoto*, Ichiro Fujii and Takahiro Wada
Department of Materials Chemistry, Ryukoku University, Japan
E-mail address*: t12m093@mail.ryukoku.ac.jp
AgNbO3 (AN) has attracted attention as a lead-free material. We have successfully fabricated AN
films on (001), (110), and (111)SrTiO3 (STO) substrates by pulsed laser deposition (PLD) 1. The
films showed different dielectric and ferroelectric properties depending on the crystal orientation of
STO substrates. In this work, we fabricated (Ag1-xLix)NbO3 (ALN) thin films with x=0.05(ALN05),
0.10(ALN10) and 0.15(ALN15) on (001), (110), and (111)STO substrates by PLD.
Before deposition of the ALN film, we deposited SrRuO3 (SRO) film as a bottom electrode on(001), (110), and (111) STO substrates. Then, we deposited ALN films with a thickness of 1~4 μm.
The fabrication conditions were as follows: laser repetition rate of 10 Hz, O2 partial pressure ofabout 225 mTorr, substrate temperature of 700°C, and 750,000 laser shots. The crystalline
structures of the ALN films were measured by /2 X-ray diffraction analysis. The surface
morphologies were observed by SEM. The relative dielectric constant r and dielectric loss tan
were measured by an LCR meter, and P-E hysteresis loops were observed using a ferroelectric
tester.
X-ray diffraction (XRD) patterns showed that ALN(x=0,0.05,0.1,0.15) films were epitaxiallygrown on (001), (110), (111) STO substrates. The diffraction peaks of the ALN films shifted to ahigher angle with increasing Li concentration. The ALN film on (001)STO had a smooth surface
with several square holes. The film on (110)STO had a striped pattern, and that on (111)STO had
trigonal pyramid-like structures. We reported similar microstructures for AN [1] and NaNbO3 (NN)[2] films fabricated on the (001), (110), and (111) STO substrates. Figure 1 shows P-E hysteresis of
the ALN05, ALN10 and ALN15 films deposited on (001), (110), and (111) STO substrates. The
ALN(x=0.1) film on (111) STO exhibits a ferroelectric behavior and has the largest remanentpolarization (Pr) of 40 C/cm2 of all the ALN films.

Fig. 1 P-E hysteresis of ALN (0.05,0.1,0.15) thin films deposited on (001), (110) and (111) SrTiO3 substrates.
1
H. Sakurai, S. Yamazoe, and T. Wada, Appl. Phys. Lett. 97, 042901 (2010).

ISAF-P2B-59 ____________________________________________________________________________________________________________________

Influences of MgTiO3 doping in Bi0.5Na0.5TiO3 on microstructureand electrical parameters
Michael Naderer, Theresa Kainz, Klaus Reichmann
Christian Doppler Laboratory for Advanced Ferroic Oxides, Graz University of Technology, Graz,
Austria
Email: Michael.naderer@tugraz.at
Bi0.5Na0.5TiO3 or BNT is one of the most promising candidates to replace Pb(Ti,Zr)O3 basedmaterials in ferroelectric applications. It was discovered in the 1960 by Smolenskii1 and receives
increasing attention since the commencement of the RoHS guideline2. Structurally, BNT forms acomplex rhombohedral perovskite with a 1 : 1 occupation of Bi3+ and Na+ on the 12-foldcoordinated A-site and Ti4+ on the 6-fold coordinated B-site.
The electrical and microstructural properties of BNT are highly modifiable. Doping of the system
can occur using hetero- or isovalent elements (e.g. Li+, Sr2+, Nd3+, Nb5+) or by formation of solid
solutions with other perovskites (e.g. Bi0.5K0.5TiO3, BaTiO3, K0.5Na0.5NbO3). The second possibility
is the most common used, since it avoids high vacancy concentrations, which destabilizes the
structure and therefore leads to decomposition.
This work describes the impact of alloying BNT with MgTiO3 (MT) on the microstructure andelectrical parameters. Unlike the heavier earth alkaline metals, Magnesium does not form a
perovskite structure with Titanium. Despite the different structures of BNT and MT, solid solutions
can be formed and Mg2+ can be introduced into the BNT lattice, which acts as structural host.
The samples were prepared via a conventional mixed oxide route with Bi2O3, Na2CO3, MgO andTiO2 as starting materials. The homogenization of the powder was carried out in a milling stepusing Tungsten Carbide milling balls and bowl on a planetary mill. The calcination reaction was
performed at 800 °C to reduce the possibility of a Bi2O3-melt. The calcined powder was again ballmilled with the equipment mentioned before. Before sintering, PEG20000 was added as a binding
agent. The disc shaped samples, pressed with a diameter of 13 mm under a pressure of 150 MPa
were debindered at 450°C and subsequently sintered at 1100 °C for 5 h.
The theoretical density and cell parameters were obtained by X-Ray diffraction, the apparent
density was calculated using the Archimedes method. The microstructure was evaluated with SEM
imaging in channeling contrast mode, instead of etching, in order to visualize grain size and domain
structure. Secondary phase inclusions were also detected with SEM and EDX. 194

1. Smolenskii G, Isupov VA, Agranovskaya A, Krainik N. New ferroelectrics of complex composition. Sov. Phys. Solid
State. 1961;2(11):2651–2654.

ISAF-P2B-60 ____________________________________________________________________________________________________________________

Dopant effects on the phase diagram and piezoelectric propertiesof lead free piezoelectric niobate ceramics
Ruiping WANG1, Takuma ARIIZUMI2, Junta ZUSHI2, Seiji KOJIMA2, and Hiroshi
BANDO1
1

National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan;
2
University of Tsukuba, Tsukuba, Japan,

Comparing piezoelectric properties of BBK and those of
BBK+Mn, it is clear that by adding Mn, kp, d33, and Qm are
all increased. That is BBK could be both hardened andsoftened by adding Mn. The behaviors are attributed to theoxygen vacancy formation and grain size growing,
respectively.

45
40
35
30
25
20
15

d33 (pC/N)

300

(a)
MPB
BBK
BBK+Mn

(b)

200
100
0
70

(c)

60

Qm

Fig. 1 shows the composition dependence of kp, d33, and Qm,
respectively. kp is 15.16 % and d33 is 30 pC/N for x = 0.01. With
increasing x, both kp and d33 tend to increase. The highest kp and d33
values, 43.38 % and 279 pC/N were obtained in x = 0.05 for BBK, and43.46 % in x = 0.05 and 369 pC/N in x = 0.06 for BBK+Mn,
respectively. That is for both BBK and BBK+Mn, piezoelectric
properties maximize around MPB. When x is beyond 0.05-0.06, kp aswell as d33 rapidly decrease. Composition dependence of dielectric
constant at room temperature maximize at around MPB, too.

kp (%)(Na0.5K0.5)NbO3 shows orthorombic sturcture at room temperature. Tetragonal is thehigh temperature and rhombohedral is the low temperature phases of it. When ATiO 3 (A =Ba, Sr, Ca, Bi0.5Na0.5, Bi0.5K0.5, Bi0.5Li0.5, …) is mixed to it, the tetragonal phase could be tuned
to room temperature. And when BZrO3 (B = Ba, Sr, Ca, ...) is mixed to it, the rhombohedralphase could be tuned to room temperature. Therefore, tetragonal-rhombohedral MPB could
be formed at room temperature by mixing (Na0.5K0.5)NbO3, ATiO3 and BZrO3 simultaneously.
It is reported that around the MPB, dielectric and piezoelectric properties were enhanced,
similar to that of PZT. To investigate effects of element additive on the dielectric andpiezoelectric properties of niobate ceramics, 0.92(Na0.5K0.5)NbO3-xBaZrO3-(0.08x)(Bi0.5K0.5)TiO3 (BBK) and 0.25 wt% MnO2 added BBK samples were prepared; and theirdielectric constant, electromechanical coupling coefficient kp, piezoelectric d33 constant,mechanical quality factor Qm and so on were studied.

50
40
0.01

0.02

0.03

0.04

0.05

0.06

0.07

BaZrO3 content x

Fig. 1 Composition dependence ofpiezoelectric properties.

2. Amtsblatt der Europäischen Union. RICHTLINIE 2002/95/EG DES EUROPÄISCHEN PARLAMENTS UND DES
RATES vom 27. Januar 2003 zur Beschränkung der Verwendung bestimmter gefährlicher Stoffe in Elektro - undElektronikgeräten. 2003;L 37:19–23.

ISAF-P2B-61 ____________________________________________________________________________________________________________________

Influence of Germanium Substitution on Dielectric andFerroelectric Properties of Ba(Fe0.5Nb0.5)O3 Ceramics
Puripat Kantha1, Nuttapon Pisitpipathsin1, Kamonpan Pengpat1,*, Amar Bhalla2
1

Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang
Mai 50200, Thailand
2
Department of Electrical and Computer Engineering, College of Engineering,
University of Texas at San Antonio, Texas 78256, USA
Email: joonjanz_462@hotmail.com, kpengpat@gmail.com,*

In this work, the influence of Ge4+ substitution on dielectric and ferroelectric properties of highdielectric BaFe0.5Nb0.5O3 ceramics was studied. The BGFN powders with a formula
BaGex(Fe0.5Nb0.5)1-xO3 where x = 0.01, 0.015, 0.02 and 0.025 were produced via mixed-oxide
method and subsequently calcined at 1100-1200C for 4 h. To form the BGFN ceramics, theresulting powders were pressed into pellets and sintered at various temperatures from 1200 to1350C for 4 h in order to obtain the ceramic with maximum density under each condition. The
phase formation, microstructure and electrical properties of these ceramics were investigated. It was
found that the Ge4+ substitution played an important role on the change of crystal structures and thephase formation of the BFN ceramics. The appearance of peak shift and peak split in XRD patterns
confirmed the structural change from cubic to monoclinic in the ceramic samples at higher Ge4+
content. The ceramics with x  0.015 contained three phases of BGFN, Ba3Fe2Ge4O14 and BaGeO3.
The amount of each phase was depended on the concentration of Ge4+ where the Ba3Fe2Ge4O14 andBaGeO3 phases were found to increase with increasing x content. It was also found that the slightly
lower densification, higher porosity and smaller grain sizes were found in the BGFN ceramics withhigher level of Ge4+ addition. This in turn affected their dielectric properties where dielectric
constant was substantially decreased while the dielectric loss was greatly improved. The optimum
composition for this system was found to be x = 0.015, where the maximum dielectric constant(~12282) with lower dielectric loss at room temperature were obtained.

ISAF-P2B-62 ____________________________________________________________________________________________________________________

Tailored MPB BiScO3-PbTiO3 piezoelectric ceramics
high temperature electromechanical transduction
magnetoelectric composites

for
and

Eider Beganza1, Harvey Amorín1, Pablo Ramos2, Alicia Castro1, Miguel Algueró1
1

Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC, Madrid, Spain
2
Departmento de Electrónica, Universidad de Alcalá, Madrid, Spain
Email: malguero@icmm.csic.es

BiScO3-PbTiO3 is the most studied system among general perovskite BiMO3-PbTiO3 (M: cation in
octahedral coordination) solid solutions with ferroelectric morphotropic phase boundaries(MPBs),195 which are under extensive research for electromechanical transduction at temperatures
between 200 and 400ºC.196 This is fostered by current industrial requirements for piezoelectric
devices for operation in harsh environments, such as engines, deep oil drilling and space.
At ICMM, we have recently reported the functionality of MPB BiScO3-PbTiO3 ceramics processedfrom nanocrystalline powders obtained by mechanosynthesis for intermediate temperature actuation(see Fig. 1). Low electric field high strain was obtained up to a temperature of 400 ºC, with large
extrinsic contributions from 300ºC. High field strain could only be induced until 200ºC, above
which dielectric breakdown occurred.197
We report here the modification of MPB BiScO3-PbTiO3 to tailor its functionality for a range ofapplications. Two approaches were addressed: (1) the introduction of Mn3+ substituting for Sc3+ inthe perovskite B-site for reducing conductivity,198 and (2) the formulation of A-site vacancies
associated with an excess of Bi+3 (in relation to charge compensated Pb2+) to enhance domain
mobility. Functional measurements oriented to high temperature actuation, magnetoelectriccomposites and energy harvesting were carried out. Terfenol-based laminate cermets and unimorph
structures were fabricated for the latter two characterizations.
4

200ºC

-3

Strain,  (x10 )

3

2

100ºC
1

RT

195

Fig. 1 Actuation characteristics of nonmodified MPB BiScO3-PbTiO3

0

0.0
1.5
2.0
R. E. Eitel,
S. J.0.5Zhang, T.1.0R. Shrout,
C.A. Randall,
I. Levin, J. Appl. Phys., vol. 96, p. 2828Electric field, E (kV mm-1)
2831, 2004.
196
A. Sehirlioglu, A. Sayir, F. Dynys, J. Appl. Phys., vol. 106, art. nº 014102, 2009.

197

M. Algueró, P. Ramos, R. Jiménez, H. Amorín, E. Vila, A. Castro, Acta Mater., vol. 60, p. 1174-1183, 2012.
M. P. Drahus et al., Phys. Rev. B, vol. 86, art. nº 064113, 2011.

198

ISAF-P2B-63 ____________________________________________________________________________________________________________________

Lead-free fibers with oriented structure
Bortolani Francesca1, Lusiola Tony1, Clemens Frank1
1

Laboratory for High Performance Ceramics, Empa, Dübendorf, Switzerland
Email: Francesca.bortolani@empa.ch

In the past ten years, the use of lead in piezoelectric ceramics has been drastically reduced and theattention has moved to lead-free materials. KNN-based ceramics are good candidates as alternatives
to PTZ, but their properties have to be improved in order to reach the PZT ones. A way to achieve
this target is by grain orientation.
Platelet-like templates, with dimensions of ~20x10x3µm, have been obtained by molten salt
synthesis (MSS) and incorporated with anisotropic powder. By thermoplastic extrusion, theplatelets have been oriented and KNN ceramic fibers were developed. The templates act as seeds
during sintering and fibers with an oriented structure are eventually obtained. Microstructuralcharacterisation of the ceramic fibers is shown. Ferroelectric behaviour of single fibers is also
analysed by the use of a unique equipment in terms of hysteresis loop, butterfly loop (S-E) andpiezoelectric coefficient (d33).

ISAF-P2B-64 ____________________________________________________________________________________________________________________

Effect of Sn4+ substitution on structure and properties in the
PbSnO3–PbZrO3–PbTiO3 ternary system
Zhuo Xing, Xiaoyong Wei, Li Jin
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China
Email: xingzhuo@stu.xjtu.edu.cn
Piezoelectric materials have been extensively investigated in the last few decades for device
applications, because of their multifunctional properties, which can be used in a broad range ofapplications. Piezoelectric properties are dependent on multiple variables, such as mophotropy,
defect structure, grain size, domain size and density. Piezoelectric ceramics in the PbSnO3–PbZrO3–
PbTiO3 (PZST) ternary system with pure perovskite structure were synthesized by conventional
solid state reaction method. Morphotropic phase boundary (MPB) compositions were confirmed by
X-ray diffraction. The influence of Sn4+ on dielectric, piezoelectric, and ferroelectric properties of
PZTST was investigated systematically. The experimental results showed that the perovskite
structure changed from tetragonal to rhombohedral symmetry and the Curie temperature (TC)decreased gradually with increasing the content of PbSnO3. The composition with Zr:Sn=1:1
ceramics exhibited favorable properties of d33, d31, Qm, kp, TC, Ec.

ISAF-P2B-65 ____________________________________________________________________________________________________________________

Novel series of temperature stable glass free LTCC Li2BO4-TiO2(B=Mo, W)
Jing Guo1, Di Zhou1, Gaoqun Zhang1, Hong Wang1
1

Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education &International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China
Email: j.gguo@stu.xjtu.edu.cn
In this work, a new series of (1-x)Li2BO4-xTiO2 (B=Mo, W) ceramics were developed for
microwave dielectric applications. They were prepared by solid state reaction method and the phasecomposition, microstructures, sintering behaviors, chemical compatibility with silver andmicrowave dielectric properties were investigated. Li2BO4 (B=Mo, W) ceramics with ultra-low
sintering temperatures (<650 oC) exhibit good microwave dielectric properties (permittivity εr= 5.5,
Q×f= 46,000~62,000 GHz), but all of them have large negative temperature coefficient of resonant
frequency (τf = -146 to -160 ppm/oC). In order to compensate the negative τf values of Li2BO4
ceramics, rutile TiO2 was selected to form (1-x)Li2BO4-xTiO2 (B=Mo, W) mixtures. The X-ray
diffraction pattern and scanning electron microscope analysis revealed that the Li2BO4 did not reactwith rutile TiO2 and a stable two-phase composite system Li2BO4-TiO2 was formed. At x = 0.45 ~
0.50, temperature stable microwave dielectric materials were obtained: εr = 10.1~12.2, Qf =29,300~34,800 GHz, and TCF ~ 0 ppm/oC.

ISAF-P2B-66 ____________________________________________________________________________________________________________________

Investigating the effects of Ba-, Ca- and Sr-doping on theproperties of PLZT
Mirjam Skof, Theresa Kainz, Klaus Reichmann
Christian Doppler Laboratory for Advanced Ferroic Oxides, Graz University of Technology, Graz,
Austria
E-Mail: m.skof@student.tugraz.at

Leadzirconate is an antiferroelectric material with interesting properties for storing charge atelevated electric fields. By replacing some of the Zr with Ti the antiferroelectric phase isdestabilized in favor of a ferroelectric phase. Introducing La3+ as a substituent for Pb2+ generates Asite vacancies, thus stabilizing the antiferroelectric phase at higher Ti contents. Isovalent doping
causes no changes in the vacancy concentration but leads to effects due to differences in mass andionic radii.
Antiferroelectric to ferroelectric phase changes can be induced by applying a critical electric fieldcausing a structural phase change resulting from the parallel alignment of anti-parallel dipoles. This
enables a large increase in stored energy. Withdrawing the electrical field leads to a hysteretic
recovery of the antiferroelectric phase.
In this study the influence of earth alkaline dopants on the properties of PLZT was investigated.
Two basic compositions with differing Zr-/Ti-content were doped with Ba, Ca and Sr according to
the formula (Pb0,89AE0,02La0,06)(Zr1-xTix)O3 (AE = Ca, Sr, Ba; x = 0,10 & 0,15). The ceramic
powders were processed via the mixed oxide route, calcined at 925°C and sintered at 1250°C. An
excess of 2 % lead was added prior calcination.
After the preparation the samples were examined with XRD to control the formation of theperovskite structure and to observe changes in the volume of the unit cell. The sintering behavior of
the ceramic was investigated with dilatometry.
To display the microstructure scanning electron microscopy was used in the channeling contrast
mode instead of etching. The chemical composition of the samples was analyzed via EDX.
The dielectric properties were measured by determining the relative permittivity, the loss factor aswell as their temperature dependence. Furthermore polarization curves were recorded leading to theswitching field. The results were compared according to the chemical composition of the samples.

ISAF-P2B-67 ____________________________________________________________________________________________________________________

Characterization and synthesis of Barium Titanate/Ni-nano metalcomposite by sol-gel process for high voltage capacitor

I S Kim1 , Mohsin Saleem 2, J S Song3, S J Jeong4 and M S Kim5
1,3,4,5Battery Research Center, KERI, Changwon, Republic of Korea, 641-120
2Department of Electrical Functionality Material engineering,
University of Science and Technology, Daejeon, Republic of Korea 305-333
Email: kimis@keri.re.kr

A modified method has been applied to synthesize high purity Barium nickel titanate powder innanometer range by sol-gel process. Conventionally, Barium titanate is synthesized by solid-state
reaction between BaCO3 and TiO2. The electrical behavior of barium titanate ceramics strongly
depend on the composition and the microstructure. Because it is chemically and mechanically very
stable, exhibits ferroelectric properties at and above room temperature, because it can be easily
prepared and used in the form of ceramic polycrystalline samples. Due to its high dielectric constantand low dielectric loss characteristics barium titanate (BaTiO3) has been used in applications suchas high voltage capacitors and energy storage devices.
In this paper, BaTiO3-Ni composite is prepared by sol-gel technique with nickel content of different
concentration for charge island in high voltage capacitors. It is thermally heated in anti-oxidation
furnace. The electrical properties were characterized in term of relative permittivity, conductivity,
C-V measurements. The electrical properties were affected by the conducting phase with increase indielectric constant. The dielectric constant is increased from 5000 to 6000 by 10 to 15 % nickel
paste which is high as compared to BaTiO3-Ni synthesize by solid state process. Phasetransformation and crystallite size of the powder were investigated by X-ray diffraction method;
particle morphology and size were studied by scanning electron microscope. We suggested that adielectric material is highly suitable for high voltage capacitors.

ISAF-P2B-68 ____________________________________________________________________________________________________________________

Sintering and Dielectric Properties of (1-x) BaTiO3 –x Sr3Ti2O7 Composite
Ceramics by a Coating Method
Chaojun Xie, Dengren Jin, Lixin Zhou, Hanting Dong, Jinrong Cheng

School of Materials Science and Engineering, Shanghai University, Shanghai, China
Email: drjin@shu.edu.cn
Sintering and dielectric properties of (1-x) BaTiO3–xSr3Ti2O7 composite ceramics fabricated by acoating method were investigated. In this research, the Ruddlesden-Popper(RP) Phase Sr3Ti2O7
powders and BaTiO3 powders were synthetized by the solid reaction, respectively, and then theirmixed powders were coated with BaTiO3 sol-gel by using ultrasonic irradiation. The structure
evolution of the BaTiO3 coating layer was investigated via transmission electron microscopy.
Microstructure and phase variation, and ions inter-diffusion during the sintering were investigatedby scanning electron microscopy and X-ray diffraction, respectively. Results show that thepermittivity and dielectric loss were sharply decreased and temperature stability was improved
effectively, due to the existence of ordered SrO-OSr stacking faults and the formation of an
inhomogeneous micro-region nearby the grain boundary through the tuning of sintering schedules
and the BaTiO3 content.

ISAF-P2B-69 ____________________________________________________________________________________________________________________

Processing and properties of BiFeO3-PbTiO3-Pb(Mn1/3Nb2/3)O3 ternary system
for high Curie temperature piezoceramics
Rui Dai, Shundong Bu, Dalei Wang, Dengren Jin and Jinrong Cheng*199
1

School of materials science and engineering, shanghai University, Shanghai 200072

BiFeO3-PbTiO3-Pb(Mn1/3Nb2/3)O3 ternary solid solution system was investigated for thedevelopment of piezoelectric ceramics with high Curie temperature. (1-x)(0.7BiFeO3-0.3PbTiO3)xPb(Mn1/3Nb2/3)O3 (BFPT-PMN) for x=0.03, 0.04, 0.05, 0.06 and 0.1 ternary ceramics were
fabricated by the conventional mixed oxide ceramic. XRD patterns reveal that all compositions possess perovskite
structure with a rhombohedral symmetry and columbite disappears with the extension of dwell time.
The surface morphology was examined by SEM. The dielectric property measurement on theceramics confirmed the high Curie temperature and the improved loss tangent with thePb(Mn1/3Nb2/3)O3 doping. The values of dielectric constant, loss tangent and the Curie temperature
were 314, 0.01 and 630 oC for x=0.03 at the sintering of 1040 oC and at the frequency of 103 Hz.

Keywords: BFPT-PMN ternary system; High Curie temperature; Dielectric properties;

 Corresponding author: email:jrcheng@staff.shu.edu.cn

Integration and Tailored Micro/Nanostructures
CLUB A
Wednesday, July 24 2013, 10:30 am - 12:00 pm
Chair:

Tadej Rojac
Jozef Stefan InstituteISAF2-G1-1 _____________________________________________________________________________________________________________________

Chemical Solution Processing of Ferroelectric Thin Films andNanostructures
Nazanin Bassiri-Gharb1, 2, Ashley Bernal1, Yaser Bastani1, Suenne Kim3, Elisa Riedo3, Haidong
Lu4, Alexei Gruverman4, Amit Kumar5, Sergei Kalinin5
1G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA,
USA
2School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA
3
School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
4
Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, USA
5
Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN, USA
Email: nazanin.bassirigharb@me.gatech.edu

Ferroelectric (FE) thin films and nanostructures find a wide range of applications in capacitiveelements, non-volatile memories, micro/nano-electromechanical system (MEMS/NEMS) sensors,
actuators and transducers, as well as energy harvesting nano- and micro-generators. With the drive
towards miniaturization, multiple intrinsic and extrinsic factors need to be leveraged in order toincrease and/or maintain the high dielectric and piezoelectric response of ferroelectric materials andreduce size effects. However, the currently available processing methods, mostly based on preexisting micromachining fabrication methods, suffer multiple limitations. Top-down approaches
can damage surface layers due to the impact of high-energy particles (detrimental to the final
electromechanical properties), or offer poor side-wall definition in wet-etch methods. Bottom-up
approaches, while allowing creation of high quality ferroelectric materials, are mostly limited inpatterning capability and compatibility for alignment with previous and subsequent layers.
Chemical solution deposition provides a very flexible approach for processing of short and highaspect ratio ferroelectric nanostructures, as well as thin and ultrathin ferroelectric films with
controlled crystallographic orientation and enhanced dielectric and piezoelectric response on avariety of substrates.
This talk gives an overview of the processing methods developed in our group for such structures
and thin films. Specifically, we report the results of a lift-mode AFM, employing a heated tip, used
to locally crystallize sol-gel films of ferroelectric materials (e.g. PbTiO3 and PbZr1-xTixO3).
Arbitrary shapes and periodic arrays of ferroelectric nanostructures are obtained on platinized sodalime glass, silicon and polyimide substrates. The feature size ranged between ~10 nm and 2.5 μm.
An alternative method for creation of ferroelectric microstructure is also explored by leveraging
thermally decomposable, UV or e-beam patterned, sacrificial material. The photoresist or e-resist
patterns are created via deep-UV lithography or e-beam patterning. A subsequent coating with theappropriate chemical solution precursor of the ferroelectric material, followed by heat treatment
leads to crystallization of the ferroelectric and removal of the sacrificial patterns. Modification of
the heat treatment profile and relative thicknesses of the resist/ferroelectic precursor result intocreation of surface micro/nano-channels of ferroelectric material or alternatively patterned
ferroelectric areas.

ISAF2-G1-2 _____________________________________________________________________________________________________________________

Confinement Printing of Thin Film Lead Zirconate Titanate for
MEMS Applications
1

A. J. Welsh1, D. Dezest2, L. Nicu2, M. A. Hickner1, and S. Trolier-McKinstry1
The Pennsylvania State University, N-224 Millennium Science Complex, University Park, USA
2
Laboratoire d’Analyse et d’Architecture des Systemes – Le Centre National de la Recherche
Scientifique, University de Toulouse, Toulouse, France
Email: ajw5000@psu.edu

Thin film electroceramics used as sensors, capacitors, actuators, etc. are patterned into
specific geometries, typically by either a wet or dry subtractive patterning approach. It is alsointeresting to consider additive patterning techniques for MEMS applications. Ceramic suspensions,pastes, and solutions have been additively patterned at the macro and meso-scale through the use of
inkjet printing, screen printing, and embossing. Powder-free ceramic solutions have been patterned
through soft lithographic techniques. Soft lithography utilizes elastomeric polymer stamps/molds toconfine or deposit solutions onto a substrate. Printing of a ceramic solution from stamp protrusions
directly onto a substrate, termed microcontact printing, has been used to deposit patterned leadzirconate titanate (PZT) thin films with comparable electrical properties to continuous PZT thinfilms. However, this technique deposits very thin layers of ceramic for every stamping cycle which
is a concern for pattern registry. Elastomeric polymers have also been used as molds for ceramic
solutions in order to deposit the film in a single processing step. These patterning techniques
produce features that have large shape deformations or cracking of the final films.
This work explores the confinement printing of PZT liquid precursors from stamp wells(rather than stamp protrusions as is used in microcontact printing). The confinement printing ofsolutions uses an initial sacrificial printing step in order to remove solution from the protrusions of
the stamp. The second stamping cycle deposits the solution from the wells of stamp. Printing fromwells doubled the thickness (e.g. from 25 to 50 nm) of deposited solution per stamping cycle overmicrocontact printing. This work studies the printing characteristics of this patterning technique,including line edge resolution, feature thickness, side wall angels, and achievable lateral featuresize. Arrays of PZT features were printed, characterized and compared to continuous PZT thin filmsof similar thickness. One micron thick printed PZT features exhibit a permittivity of 1030 and a loss
tangent of 0.024. The hysteresis loops are well formed, without pinching of the loops. The patternedfeatures showed remanent polarizations of 29µC/cm2, and coercive fields of 52kV/cm. The
piezoelectric response of the features produced an e31,f of -7 C/m2.

ISAF2-G1-3 _____________________________________________________________________________________________________________________

Ferroelectric Order in Nanoscale Perovskites and its Control via Colloidal
Processing

Gabriel Caruntu1,2, Amin Yourdkhani1,2, Mark J. Polking3,4, Daniela Caruntu1, Valeri Petkov5,
Christian F. Kisielowski6, Vyacheslav V. Volkov7, Yimei Zhu6, A. Paul Alivisatos8 andRamamoorthy Ramesh9
1

Advanced Materials Research Institute, University of New Orleans, New Orleans, Louisiana
70148, USA
2

Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA
Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
4
Department of Chemistry, Harvard University, Boston, Massachusetts, USA
5
Department of Physics, Central Michigan University, Mount Pleasant, MI 48859, USA
6
National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
7
Condensed Matter Physics and Materials Sciences Department, Brookhaven National Laboratory, Upton, NY 11973,
USA
8
Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.
9
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
3

In an attempt to address one of the fundamental questions related to the survival offeroelectricity in technologically important perovskites, we present here an atomic-scale insight into
the fundamental nature of ferroelectric order down to its ultimate size limit using. To this end weused monodisperse, aggregate-free BaTiO3 colloidal nanocrystals as a model system.
Atomic resolution mapping of local ferroelectric distortions indicates a coherent, nearly linear,monodomain state accompanied by local structural distortions. The persistence of ferroelectriccoherence in BaTiO3 is further supported by single-particle studies with off-axis electron
holography and PFM measurements of individual nanocubes demonstrating ferroelectric switching
behaviour at room temperature. These PFM
studies further demonstrate the ultimate
stability limit of ferroelectric order. Carefulatomic PDF studies point to the parallel
roles played by surface-induced relaxationand depolarization effects in the dissolutionof ferroelectric order at finite dimensions
and indicate considerable structuralFig. 1. Electron holography images of an individual 10 nm
disorder and dipole decoherence, even in
BaTiO3 nanocube below (a) and above (b)the Curie
conductive GeTe with strong polarization
temperature demonstrating the polarization structure in the
ferroelectric state and its eradication above the phase transition
screening. These studies also demonstratetemperature
the utility of colloidal morphology control
as a means of stabilizing the polar state at nanoscale dimensions. These experiments reveal theultimate limit of the ferroelectric state and provide a pathway to unravelling the fundamental
physics of nanoscale ferroelectricity at the smallest possible size scales.

ISAF2-G1-4 _____________________________________________________________________________________________________________________

Structural and Electric Properties of Ca2Nb3O10 Thin Films
grown by Electrophoretic Method
Sang Hyo Kweon1, Mir Im1, Sahn Nahm1
1

Department of Material Science and Engineering, Korea University, Seoul, South Korea
Email: petitzel1223@korea.ac..kr

KCa2Nb3O10 ceramics, Dion-Jacobson layered perovskite materials, have been widely investigatedbecause they can be easily exfoliated to the nano-sized sheets which can be used to the future
multilayer capacitors with a small size and high performance. A KCa2Nb3O10 phase was formed at
900oC and a dense ceramics were obtained after sintering at 1375oC for 10 h. A proton exchange
process was carried out to produce the intermediate phase of HCa2Nb3O10 and the stable(Ca2Nb3O10)- nanosheet colloids were formed using the mixture of the HCa2Nb3O10 powders,tetrabutylammonium hydroxide (TBAOH) solution and water having the same TBA+/H+ ratio. The
exfoliated (Ca2Nb3O10)- nanosheets were dispersed into the acetone intermediate, which was used toform the thin film by the electrophoretic method under 100 V electric source. The electrophoretic
thin films were then annealed at various temperatures for 30 min under air condition and all thefilms have the Ca2Nb3O10 phase. In particular, a high dielectric constant of 65 with a loss of 2.1% at
100 kHz was obtained from the film annealed at 600oC and this film also showed the low theleakagecurrent
densityof
1*10-7A/cm2
at
0.1
MV/cm.

ISAF2-G1-5 _____________________________________________________________________________________________________________________

Multiferroic Properties of Bismuth Ferrite Porous Thin Films
Stella Skiadopoulou, Eliana Carvalho, Alichandra Castro, Paula Ferreira, Paula M. Vilarinho
Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, Aveiro,
Portugal
Email: styliani@ua.pt
Magnetoelectric multiferroics’ ability of magnetic field manipulation via electric fields or vice versa
can be extremely promising for information storage applications, leading to thinner, as well as
flexible devices, with significantly high energetic efficiencies and huge capacities200. Bismuth
ferrite (BiFeO3), being the only single-phase multiferroic at room temperature, is considered themodel multiferroic201. Porous matrices, apart from providing lighter devices, have a great
importance for a large range of applications, since novel architectures can be achieved by theincorporation of diverse materials in the pores, producing multifunctional films202.
For that purpose, BiFeO3 porous thin films were prepared by combination of simple processes:
modified sol-gel (with a block copolymer), Evaporation Induced Self-Assembly (EISA) method anddip-coating deposition on Pt/TiO2/SiO2/Si substrates. Different copolymer concentrations were usedin the as-prepared solutions, in order to study the effect of porosity on the multiferroic properties.
Additionally, film deposition was conducted at increasing deposition velocities, aiming at thecharacterization of films with varying thicknesses. Ferroelectric and ferromagnetic properties werestudied at the nanoscale via Piezoresponse Force Microscopy (PFM) and Magnetic ForceMicroscopy (MFM) respectively. Dense films with similar characteristics were prepared forcomparison proposes.
The variations in the piezoresponse signal of porous films with increasing porosity and decreasing
thickness is discussed and related with the microstructure of the films, domain configuration andsubstrate interaction.
Acknowledgment
The authors are grateful to FCT and FEDER (QREN - COMPETE) for financial support
PTDC/CTM/098130/2008).

200

Spaldin, N.A., S.W. Cheong, and R. Ramesh, Multiferroics: Past, present, and future. Physics Today, vol. 63, p. 3843, 2010.
201

Martin, L.W. and R. Ramesh, Overview No. 151 Multiferroic and magnetoelectric heterostructures. Acta Materialia,
vol. 60, p. 2449-2470, 2012.
202

Ferreira, P., et al., Nanoporous Piezo- and Ferroelectric Thin Films. Langmuir, vol. 28, p. 2944-2949, 2012.

Pb-Free Piezoelectrics
CLUB B
Wednesday, July 24 2013, 10:30 am - 12:00 pm
Chair:

Clive Randall
Pennsylvania State University

ISAF2-G2-1 _____________________________________________________________________________________________________________________

Texturation of lead-free BaTiO3-based piezoelectric ceramics
A. Ngueteu-Kamlo1, F. Levassort2, M. Pham Thi3, P. Marchet1
1

Laboratoire de Science des Procédés Céramiques et de Traitements de Surface, UMR 7315 CNRS,
Université de Limoges, Centre Européen de la Céramique, 12, rue Atlantis,
F-87068
Limoges Cedex, France.

2

Université François Rabelais de Tours, GREMAN CNRS 734, 10 Boulevard Tonnellé, BP 3223,
37032 TOURS Cedex 1, France

F-

3

THALES Research & Technology France, Campus Polytechnique, 1, Av. Augustin Fresnel,
91767 Palaiseau Cedex - France

F-

Email: pascal.marchet@unilim.fr
Nowadays, piezoelectric ceramics are integrated in a wide range of devices, in particular inultrasonic applications (underwater sonar systems, medical imaging, non-destructive testing…). Most ofthem use Pb(Zr,Ti)O3 (PZT). However, due to health care and environmental problems, lead content
must be reduced in such applications203. Recent reviews demonstrated that few lead-free materials
families can be considered: the alkaline-niobates (K0.5Na0.5NbO3), the alkaline-bismuth-titanates(Na0.5Bi0.5TiO3 Ka0.5Bi0.5TiO3), the bismuth layered compounds (Bi4Ti3O12) and barium titanate basedmaterials (BaTiO3)204,205.
One of the limitations of ceramic materials is their isotropic nature. This is the reason why
texturation process has been developed in order to improve their properties in particularelectromechanical parameters. The aim of the present study is thus to obtain textured BaTiO3 basedmaterials by using the templated grain growth process (TGG) and to measure their piezoelectric
properties. Nanosized BaTiO3 powders were prepared by classical solid state route at relatively low
temperature. BaTiO3 templates of different
morphologies were elaborated by a molten salts
process. Dispersing agent, binder and plasticizer,
the mixture of the templates and matrix particles
was then dispersed in the appropriated solvent using
non-aqueous formulation. The slurry was then tapecasted on plastic film. After drying, the green sheet
was cut, stacked, thermo compressed and thensintered at the appropriated temperature. This
process allowed obtaining highly-oriented materials
with a texturation degree around 95% (fig. 1),
presenting Kt values around 35-40%, higher thanfor non-textured BaTiO3 ceramics.
Fig. 57: X-ray diffraction diagram of (tetragonal)
Acknowledgements: The authors kindly
textured sample BaTiO3 and (tetragonal) nonacknowledge financial support from the French
textured BaTiO3 ceramic as reference.
Research National Agency (ANR), project203

Directive 2002/95/EC, Official Journal of the European Union, 13.2.2003

204

J. Rodel, W. Jo, T.P. Seidert, E-M. Anton, T. Granzow, D. Damjanovic, J. Am. Ceram. Soc. 92, 1153-1177, 2009

205

P.K. Panda, J. Mater. Sci. 44, 5049-5062, 2009

HYPERCAMPUS

ISAF2-G2-2 _____________________________________________________________________________________________________________________

Electric-Field-Induced phase switching in textured Ba-doped
bismuth ferrite-lead titanate
Meghdad Palizdar1,5, Tim P. Comyn1 ,Tim J. Stevenson1, Stephen F. Poterala2 , Gary L. Messing2,
Ender Suvaci3, Annette P. Kleppe4, Andrew J. Jephcoat4 and Andrew J Bell1
1
Institute for Materials Research, University of Leeds, LS2 9JT, Leeds, UK
Department of Materials Science and Engineering, Pennsylvania State University, University Park, USA
3
Department of Materials Science and Engineering, Anadolu University, Eskisehir, Turkey
4
Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campu s, Didcot, Oxfordshire, UK
5Institute for Materials Research, Iran University of Science and Technology, Tehran, Irane-mail: ml07m2p@leeds.ac.uk
2

The solid solution between bismuth ferrite and lead titanate (xBiFeO3-(1-x)PbTiO3 or BFPT)
possesses a morphotropic phase boundary (MPB) between the rhombohedral and tetragonal forms
at x=0.7. It is of interest to investigate the influence of field-driven rhombohedral-tetragonal phasetransitions across the MPB, to determine whether correctly oriented BFPT can provide both giant
piezoelectric properties and significant magnetoelectric coupling.
Here, we used the reactive templated grain growth (RTGG) technique to prepare
crystallographically textured BFPT ceramics, by using BaTiO3 as templates. It was found thatconventional XRD is not sufficient for evaluating texture development in partially oriented
60:40BFPT ceramics. Hence, synchrotron radiation experiments were used in two different
directions, perpendicular and parallel to the cast direction. These experiments highlighted
significant differences in crystallographic orientation between perpendicular and parallel directions.
Also, vibrating sample magnetometry (VSM) data, measured with both cast direction normal andparallel to the magnetic field, clearly showed orientation of magnetic response as a result of
crystallographically textured structure. The coercive field of 177 Oe and maximum magnetizationof 1.43 emu/g was obtained when magnetic field applied normal to the cast direction. By applying
the magnetic field along to the cast direction, a far higher coercive field of 908 Oe, and lower
maximum magnetization of 0.29 emu/g was realized. VSM data suggested the existence offerromagnetic textured BFPT at room temperature. However, EDX data showed that BaTiO3
templates dissolved in the matrix and resulted in Ba+2- doped BFPT with the formula of
Bi0.57Fe0.55Pb0.34Ba0.08Ti0.44Ox.
A ferroelectric Curie temperature of ~570 oC and remanent polarization of 2Pr = 60 µC/cm2 at 7.5
kV/mm were recorded.
Finally, in situ synchrotron diffraction shown that by applying external electric filed on mixedrhombohedral and tetragonal Ba+2- doped BFPT phases along [001] direction, single phasetetragonal was obtained.
To summaries, BaTiO3 has succeeding in generating a textured, ferromagnetic system.

ISAF2-G2-3 _____________________________________________________________________________________________________________________

Fabrication of Barium Titanate Grain-oriented Ceramics using
Barium Titanate Particles with Different Crystal Structure byElectrophoresis Deposition Method under High Magnetic field
and Their Dielectric and Piezoelectric Properties
Satoshi Wada1, Eigo Kobayashi 1, Shintarou Ueno1, Kouichi Nakashima1, Takahiro Takei1,
Nobuhiro Kumada1, Thoru Suzuki2, Tetsuro Uchikoshi2, Yoshio Sakka2, Eisuke Magome3, Chikako
Moriyoshi3, Yoshihiro Kuroiwa3, Yasuo Miwa4, Shinichiro Kawada4, Suetake Omiya4, andNoriyuki Kubodera4
1

Material Science and Technology, Interdisciplinary Graduate School of Medical and Engineering,
University of Yamanashi, 4-4-37 takeda, Kofu, Yamanashi 400-8510, Japan
2
National Institute for materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
3
Murata Manufacturing Co., Ltd. 2288 Ooshinohara, Yasu, Shiga 520-2393, Japan
4
Department of Physical Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima,
Hiroshima 739-8526, Japan
Email: swada@yamanashi.ac.jp

Barium titanate (BaTiO3, BT) grain-oriented ceramics were prepared by electrophoresis deposition(EPD) method under high magnetic field (HM-EPD) of 12 T. For this objective, two kinds of BT
partickles, i,e., the tetragonal BT single-domain nanoparticles with c/a ratio of 1.009 and size of 99
nm and hexagonal BT nanoparticles with high c/a ratio of 2.55 and size of about 300 nm, were usedin this study. Using these BT nanoparticle slurry, BT nanoparticle accumulations were prepared by
EPD with/without high magnetic field.
As the results, from X-ray diffraction (XRD)
measurements, the accumulation of tetragonal BT nanoparticles was assigned to randumly oriented
one while the accumulation of hexagonal BT nanoparticles was assigned to <001> oriented one
with a degree of orientation of almost 40 %. After binder burnout, these accumulations weresintered at 1250 ˚C to inhibit abnormal grain growth, and from XRD measurements, it was revealed
that the BT ceramics prepared using tetragonal BT nanoparticles exhibited completely randumlyoriented one, while the BT ceramics prepared using hexagonal BT nanoparticles showed <111>oriented one with a degree of orientation of almost 79 %. These results revealed that the magnetic
feild of 12 T was insufficient for magnetic allignment of tetragonal BT nanoparticles because of its
low diamagnetic anisotropy. Moreover, the microstructure oft he <111> oriented BT ceramics wasobserved using a scanning electron microscope (SEM) with EBSD, and its grain size was estimatedat almost 1 µm. Therefore, using hexagonal BT nanoparticles, fine-grained BT ceramics along<111> orientation of almost 80 %.

ISAF2-G2-4 _____________________________________________________________________________________________________________________

Anisotropy of piezo- and ferroelectricity in textured
K0.5Na0.5NbO3-based materials from novel texturing method
Astri Bjørnetun Haugen1, Gerhard Henning Olsen1, Francesco Madaro1, Maxim Morozov1, Goknur
Tutuncu2, Jacob L. Jones2, Tor Grande1 and Mari-Ann Einarsrud1
1

Department of Materials Science and Engineering, Norwegian University of Science andTechnology (NTNU), Trondheim, Norway
2
Department of Materials Science and Engineering, University of Florida, Gainesville, Florida,
USA
Email: astri.b.haugen@ntnu.no
Lead-free piezoelectrics have been shown to exhibit properties similar to Pb(Zr,Ti)O3 throughdoping and introduction of preferential grain orientation (texture) in (K,Na)NbO3 (KNN). Textured
KNN is normally obtained from templated grain growth (TGG) with plate-like NaNbO3 templates
in a KNN matrix.
In this work, <001>pc (pc for pseudo-cubic indices) textured KNN and KNN doped with Mn and
Mn, Li and Ta were produced by TGG with needle-like KNN templates. Tape casting with a gateddoctor blade was used to align the templates. Characterization of the sintered compacts revealed
weak <001>pc texture and some non-beneficial <110>pc texture in the tape cast plane resulting inlower piezoelectric performance than corresponding non-textured materials. This is attributed torotation of the templates around their long axis. Alignment of the templates’ long axes did,
however, introduce a larger degree of <100>pc texture along the tape cast direction.
Synchrotron X-ray diffraction using a 2D detector confirmed the texture as described above andallowed in situ measurement of domain switching during electric field loading. The largest relative
intensity changes within sets of {hkl}s vs. electric field magnitude were observed for field applied
parallel to the direction of highest texture (tape cast direction) as shown in Fig.1. This is attributed
to better accomodation of the strain from domain switching in the direction of high texture.
Piezoelectric constant (d33) measured after the in situ study was also highest in this direction due tohigh <100>pc texture. These results are therfore consistent with the polarization rotation mechanismof piezoelectric enhancement for orthorhombic symmetry.206

Fig. 58: Surface plots of the diffracted {200}pc of KNN during in situ electric field loading.
206

M. Davis et a,,. J. Appl.Phys., vol. 101, p.054112, 2007.

ISAF2-G2-5 _____________________________________________________________________________________________________________________The electric property of textured lead-free piezoelectric thick films
Jiwei Zhai*, Bo Shen, and Fang Fu,
Functional Materials Research Laboratory, Tongji University, Shanghai 200092, China
apzhai@tongji.edu.cn(h00)-textured lead free piezoelectric thick films were fabricated by tape casting and screen
printing method, respectively. Main family members of lead free piezoelectric materials such as BT,
NBT, and KNN-based thick film are all investigated. The textured (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3(BCZT) thick films were fabricated via screen printing using anisotropically shaped BaTiO3
templates on platinum substrate. The textured BCZT thick film exhibited excellent electric
properties with the piezoelectric constant d33*=427 pm/V and remnant polarization Pr=15.8 μC/cm2
sintered at 1300 °C for 4 h with 81% of Lotgering's factor.
High-stain textured thick film with the composition of NBT-BT-KNN was also fabricated. The
grain orientation degree reached to 75%. The large signal d33 reached to 349 pm/V, which iscomparable to the value of PZT thick films. Furthermore, the temperature stability of the textured
NBT-BT-KNN thick film was also evaluated. A ferroelectric-antiferroelectric phase transition wasstarted at 70 oC and both ferroelectric and antiferroelectric phase were co-existed in the thick film.
Tape casting method was also applied on KNN-based textured thick films. The grain orientation
degree of KNN textured thick film was 61%. The piezoelectric constant d33 improved from 38 to
61 pm/V. The grain orientation degree increased to 82% with adding 6 mol% LiSbO3. The
piezoelectric constant d33 was enhanced to 173 pm/V due to the addition of LiSbO3.

ISAF2-G2-6 _____________________________________________________________________________________________________________________

Fabrication of Random and Textured Lead-free (K,Na)NbO3 inFiber, Ribbon and Ceramic Form
Sedat Alkoy1,2, Ebru Mensur Alkoy3, Ayse Berksoy Yavuz1,2,1

Dept. Materials Sci. & Eng., Gebze Institute of Technology, Gebze, Kocaeli, Turkey
2
ENS Piezodevices Ltd., Gebze, Kocaeli, Turkey
3
Faculty of Engineering and Natural Sciences, Maltepe University, Maltepe, Istanbul, Turkey
Email: sedal@gyte.edu.tr
To achieve high electroacoustic performance on the piezoelectric ceramics, there are various
approaches. Piezoelectric ceramics in the bulk form have poor electroacoustic properties due to highacoustic impedance. Flexible piezoelectric transducers can be one of the approaches to get better
properties. The main design proposed for the problem is the piezocomposite where piezoelectric fibers
or particles are embedded in a passive polymer matrix.
In this study, lead-free potassium sodium niobate (KNN) piezoelectric fibers were fabricated using
sodium alginate gelation method. The thickness of the sintered fibers could be adjusted depending on
the drawing nozzle and 300 µm thick fibers were used in this study. First of all, fibers were obtainedwith random crystallographic orientation. These fibers were embedded into the polymer matrix and 1-3
piezocomposites were prepared. Capacitance and tan loss measurements were taken at from 1 kHz to 1
MHz frequency range. Dielectric constant and loss of the composite samples were calculated as 81 and
1%, respectively.
Besides fabricating piezocomposites with random oriented fibers, to obtain better properties, the study
was done to fabricate textured KNN ceramic fibers. Anisometric template particles, i.e. microscale
single crystal particles with non-equax morphology are used in the fabrication of crsytallographicallytextured ceramics as templates. Sodium niobate – NN [NaNbO3] templates were synthesized in platelike morphology by the molten salt synthesis method and in needle-like morphology by thehydrothermal synthesis method. Alginate gelation was used together with the templated grain growth(TGG) method for the first time to fabricate textured (K,Na)NbO3 based lead-free piezoceramics. KNN
with plate-like NN templates was fabricated continuously in ribbon form and KNN with needle-like NN
templates was fabricated in fiber form. The micrograph of plate-like NN templates, the textured
microstructure of KNN ribbons are given in Figure 1 along with the XRD patterns taken from thesurface and the cross-section of the ribbon, demonstrating the crystallographic texture in <001>
direction.

surfacecross-section

Fig. 59: (a) Plate-like NN templates, (b) Microstructure and (c) XRD patterns of textured KNN ribbons.

Pb-based ceramics: Domains
CLUB C
Wednesday, July 24 2013, 10:30 am - 12:00 pm
Chair:

Celine Lichtensteiger
DPMC - University of Geneva

ISAF3-G3-1 _____________________________________________________________________________________________________________________

Study of Domain Structure and Phase Transitions in
Pb(Zr1-xTix)O3 Single crystals
Zuo-Guang Ye, Yujuan Xie, Alexei A. Bokov and Xifa Long
Department of Chemistry and 4D LABS, Simon Fraser University,
Burnaby, BC, V5A 1S6, Canada
Email: zye@sfu.ca
PbZr1-xTixO3 (PZT) system has been extensively studied over the past decades for both industrial
applications and fundamental research. Recently, PbZr1-xTixO3 single crystals with compositions(0.2 ≤ x ≤ 0.65) across the mophotropic phase boundary (MPB) region have been grown in ourlaboratory by a top-seeded solution growth (TSSG) technique. The availability of PZT single
crystals makes it possible to systematically investigate the correlation between structural evolution
and electrical properties in PZT system.
In this work, the domain structure and phase transitions of PZT single crystals with compositions
x=0.32, x=0.42, x=0.46 and x=0.62 are studied by polarized light microscopy (PLM),
piezoresponse force microscopy and dielectric measurements. PLM observation shows an increaseof extinction angle in the two rhombohedral crystals: x=0.32 at 340 °C, and x=0.42 at 250°C,
indicating a thermally induced polarization rotation accompanied with the rhombohedral (R) to
monoclinic (M) phase transition. The ferroelectric to paraelectric phase transition in x=0.32 is offirst order with a discontinuous change of birefringence around TC=351°C. The dielectricmeasurements show anomalies below TC, confirming the R-M phase transitions in both crystals. For
the MPB composition x=0.46, PLM shows a monoclinic symmetry with complicated domain atroom temperature, which upon heating changes to a tetragonal phase at about 286°C and then to a
cubic phase at TC=394 °C. Crystals of composition x=0.46 exhibit the best piezoelectric properties,
with a piezoelectric constant d33=1223 pC/N and an electromechanical coupling factor k33=80%.
The (100) plate of the tetragonal crystal with composition x=0.62 is optically isotropic, but the(011) plate shows a small birefringence at 45° (angle between polarizer and <100> direction). Thisis because of the formation of nano-sized tetragonal domains due to the instability of theferroelectric phase. A total compensation is achieved in the (100) plate, but in the (011) plate thecompensation is only partial. By applying an electric field, macroscopic domains can be induced ina (100) plate at a field of 25kV/cm and the crystal becomes anisotropic. Birefringence becomeslarger with increasing field and shows a maximum value Δn=0.012 at the field of 30kV/cm. Afterthe electric field is removed, the crystal changes back to isotropic, indicating the field induced
macroscopic domain is metastable. We discuss the mechanisms for the formation of domain
structures and phase transitions in PZT single crystals and compared them with the behaviour andmechanisms of relaxor ferroelectrics.

This work is supported by the Office of Naval Research (Grants No. N00014-11-1-0552 andN00014-12-1-1045) and the Natural Science and Engineering Research Council of Canada.

ISAF3-G3-2 _____________________________________________________________________________________________________________________Morphotropic interfaces in Pb(Mg1/3Nb2/3)O3-PbTiO3 single
crystals
1

I. Rafalovskyi1, M. Guennou1, I. Gregora1, and J. Hlinka1
Institute of Physics, Academy of Sciences of the Czech Republic
Na Slovance 2, 182 21 Prague 8, Czech Republic
Email: hlinka@fzu.cz

Large electromechanical coupling constant, piezoelectric coefficient and strain level of poled(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) single crystals have attracted considerable interest
because of their excellent performance in various solid state electromechanical sensors andactuators. 207,208,209 It is well understood that the piezoelectricity results from the ferroelectricordering and that the best piezoelectric figures of merit are found in materials with the composition
corresponding to the so-called morphotropic phase boundary.3 This phase boundary is only very
weakly temperature dependent, but in a narrow concentration region around x ≈ .33 (which
precisely comprises in the materials of technological interest), one may typically pass from therhombohedral-like phase to the tetragonal-like phase at a certain210 temperature TRT, i.e. one may
cross the MPB also upon heating.
Here we have investigated passage across the TRT
temperature in 0.68PMN-0.32PT single crystal and in
the course of our studies we have observed formationof macroscopic planar interfaces between therhombohedral-like and tetragonal-like phase, or, inother words, interfaces that could be denoted as "realspace morphotropic phase boundaries". The opticalobservation has been complemented by Raman
spectroscopy investigations what allowed to establish Fig. 60: Mesoscopic stripe pattern formed
in a PMN-PT crystal by heating after aseveral interesting links to the previous observations.
field-cooling process.

207

S. E. Park and T. R. Shrout, “Ultrahigh strain and piezoelectric behavior in relaxor based ferroelectric single
crystals”, J. Appl. Phys., vol. 82, p. 1804, 1997.
208

D. Damjanovic, M. Budimir, M. Davis and N. Setter, “Monodomain versus polydomain piezoelectric response of
0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 single crystals along nonpolar directions”, Appl. Phys. Lett., vol. 83, p. 527, 2003.
209

S. Zhang and F. Li, “High performance ferroelectric relaxor-PbTiO3 single crystals: Status and perspective”, J. Appl.
Phys., vol. 111, p. 031301, 2012.
210

Z. Feng, X. Zhao, and H. Luo, “Bias field effects on the dielectric properties of 0.67Pb(Mg 1/3Nb2/3)O3–0.33PbTiO3
single crystals with different orientations”, Solid State Commun., vol. 130, p. 591, 2004.

ISAF3-G3-3 _____________________________________________________________________________________________________________________

In situ TEM on Phase Transitions in Perovskite Ceramics
Xiaoli Tan, Hanzheng Guo, Cheng Ma
Department of Materials Science and Engineering, Iowa State University, Ames, Iowa/USA
Email: xtan@iastate.edu
Perovskite oxides are rich in electric field-induced phase transitions, such as the relaxor-toferroelectric and antiferroelectric-to-ferroelectric ones. In this study, electric field in-situ TEM
technique is used to investigate the seemingly unlikely ferroelectric-to-relaxor and ferroelectric-toantiferroelectrictransitionsatroom
temperature.
Specifically,
antiferroelectric
Pb0.99Nb0.02[(Zr0.57Sn0.43)0.92Ti0.08]0.98O3 (PNZST43/8/2) and relaxor Pb0.92La0.08(Zr0.65Sn0.35)O3(PLZT8/65/35) ceramics are focused in this study.
During the application of the very first cycle of electric field to these ceramics, the electric field in
the first quarter cycle transforms the antiferroelectric PNZST43/8/2 or the relaxor PLZT8/65/35
phase into a ferroelectric phase. The “induced ferroelectric phase” is metastable and its polarizationis largely preserved during the second quarter cycle. The remanent polarization is switched to thereversed direction in the third quarter cycle when the electric field with reversed polarity increases.
The coercive field, EC, is at the intercept of the polarization curve with the electric field axis in thethird quarter cycle. Presumably, the induced metastable ferroelectric phase behaves as a normal
ferroelectric and switches its polarization through a normal domain nucleation and growth process.
However, there have been indications that this polarization reversal is quite unusual and unique
because it takes place through seemingly unlikely phase transitions at close vicinity of EC. These
reverse phase transitions produce “transient antiferroelectric” and “transient relaxor” phases during
the polarization switching process of the induced ferroelectric phase. These transient phases are
directly visualized in real time at nanometer resolution with the electric field in-situ TEM
technique.
In addition, electric field-induced phase transitions in (K0.5Na0.5)NbO3-based ceramics were also
investigated with the in situ TEM technique.

ISAF3-G3-4 _____________________________________________________________________________________________________________________Heat treatment effects on domain configuration and strain
behavior under electric field in undoped Pb[ZrxTi1-x]O3
ferroelectrics

Ljubomira Ana Schmitt1, Hans Kungl2, Manuel Hinterstein3, Hans-Joachim Kleebe1,
Michael J. Hoffmann2, Hartmut Fuess1

1

Institute of Materials and Geo-Sciences, Technische Universität Darmstadt,
64287 Darmstadt, Germany
2
Institute for Ceramics and Mechanical Engineering, Karlsruhe Institute of Technology,
76131 Karlsruhe, Germany
3Institut für Werkstoffwissenschaften, Technische Universität Dresden,
01062 Dresden, Germany
Email: Ljuba@st.tu-darmstadt.de

Undoped Pb [ZrxTi1-x]O3 (PZT) ceramics with Zr/Ti ratios 52/48, 52.5/47.5, 56/44 and 57.5/42.5
from the tetragonal and the rhombohedral side of the morphotropic phase boundary were examined.
Effects of heat treatments below and slightly above Curie temperature on domain configuration andstrain behavior were investigated.
Changes in domain configuration during the heating cycles were observed by in situ hot-stagetransmission electron microscopy1. After cooling down, the domain configurations do not
immediately return to their initial shape. However, after exposure at ambient temperature conditions
for 96 h, they redevelop to a state largely similar to the initial configuration. During the transient
post annealing state, changes in the strain behavior under electric field were found, when comparing
the strain behavior of non-heat treated and heat treated ceramics right after cooling. The enhanced
response to 4 kV/mm electric fields results in qualitatively different effects for PZT from thetetragonal side and from the rhombohedral side of the morphotropic phase boundary.
Overall the experiments show that after annealing the domain configuration is reversible, but time isrequired to return to the initial patterns. During the transient non equilibrium state, enhanced
influence of electric field was detected, which may show up in different forms, depending on thematerial and the level of the electric fields applied.

1

L. A. Schmitt, R. Theissmann, J. Kling, H. Kungl, M. J. Hoffmann and H. Fuess “In situ hot-stage transmission
electron microscopy of Pb(Zr0.52Ti0.48)O3”, Phase Transitions, vol. 81, p. 323-329, 2008.

ISAF3-G3-5 _____________________________________________________________________________________________________________________

Field-induced phase transitions in soft Pb(Zr1-xTix)O3 at themorphotropic phase boundary
Yo-Han Seo1, Daniel J. Franzbach1,2, Jurij Koruza3, Andreja Benčan3, Barbara Malič3, Marija
Kosec3, Jacob L. Jones4, Kyle G. Webber1
1

Institute of Materials Science, Technische Universität Darmstadt, 64287, Darmstadt, Germany
2
Graduate School of Computational Engineering, Technische Universität Darmstadt, 64287,
Darmstadt, Germany
3Jožef Stefan Institute, Jamova c. 39, Si-1000, Ljubljana, Slovenia
4
Department of Materials Science and Engineering, University of Florida, 32611, Gainesville, FL,
USA
Email: webber@ceramics.tu-darmstadt.deFerroelectric lead zirconate titanate, Pb(Zr1-xTix)O3 (PZT), displays well-known nonlinear
ferroelectric and ferroelastic behavior during electrical and mechanical loading resulting in
hysteretic behavior. It has been demonstrated that both the ferroelectric and ferroelastic behavior of
PZT are influenced by the composition, where enhanced ferroelectricity and ferroelasticity areobserved at the morphotropic phase boundary (MPB), which separates the ferroelectricrhombohedral and ferroelectric tetragonal phases in the composition-temperature phase diagram.
Some investigators have attributed the enhanced properties at the MPB to the coexistence of thetetragonal and rhombohedral phases, the presence of an additional monoclinic Cm phase, or the
existence of nanopolar regions in the MPB region of PZT. These works, however, have notaddressed the influence of an external electrical or mechanical field on the stable phase in PZT.
Recent ferroelectric and ferroelastic
measurements of various PZT compositions(Pb0.98Ba0.01(Zr1-xTix)0.98Nb0.02O3, 0.40<x<0.60) in
the vicinity of the MPB have shown exceptionallylarge remanent strain-to-switching strain ratios, insome compositions above the theoretical values
allowed by domain switching alone (Fig. 1). Thisstrongly indicates the presence of hysteretic
processes in addition to ferroelectricity and Fig. 61: The measured ratio of remanent strain
ferroelasticity during the application of an external produced during electrical (a) and mechanical (b)field. To further investigate this observed behavior, loading to the switching strain is shown for various
a phenomenological free energy analysis was used PZT compositions. The theoretical maximum ratio
allowedbyferroelectricity
andto predict the effects of electric field and stress on values
ferroelasticity in a polycrystalline are also shown
the stable phase in ferroelectrics and predict the for the rhombohedral (solid line) and tetragonalsusceptibility of the rhombohedral and tetragonal (dotted line) phases. The maximum applied electric
structure to a field-induced phase transition. field and stress were 6 kV/mm and -400 MPa.
Modeling results were in very good agreementwith experimental observations and indicate the relative importance of such phase transitions onmacroscopic behavior, giving an indirect method to observe field-induced phase transitions inpolycrystalline ferroelectrics.

ISAF3-G3-6 _____________________________________________________________________________________________________________________

Depolarization of High Temperature xPbTiO 3 - yBiScO3 zBi(Ni1/2Ti1/2)O3 Ternary Perovskite Piezoelectric System
Troy Ansell1, David Cann1
1

School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University,
Corvallis, OR/USA
Email: ansellt@onid.orst.edu

Most common piezoelectric systems that incorporate lead titanate (PT)211 experience a degradationin the poled state upon heating at temperatures below the Curie temperature (TC). Thisphenomenon, known as the depolarization temperature (TD), is observed in poled materials throughfive different methods212: in-situ X-ray diffraction, dielectric loss measurements, in-situ d33,
temperature-stimulated current (TSC), and the piezoelectric resonance method. All of thesemeasurements were applied to the high temperature piezoelectric system xPbTiO3 – yBiScO3 –zBi(Ni1/2,Ti1/2)O3 (PT-BS-BNiT). For different compositions, the value of TD ranged between 275°C – 375°C. It has also been observed that the values of the piezoelectric coefficient increased as
the temperature is raised in in-situ d33 [pm/V].
Fig. 1 displays an example of the depolarization via an in-situ d33 measurement for the compositionx = 50, y = 30, z = 20. The depolarization of soft PZT is included for comparison. This ternary PTBS-BNiT system includes two binary systems PT-BS and PT-BNiT and this research demonstrates
that both d33 and TD increase as the composition moves from PT-BNiT to PT-BS.

Figure 1. The depolarization of thecomposition 50PT-30BS-20BNiT is shownas compared to soft PZT. The temperature ofdepolarization is the temperature at which
the value of d33 begins to drop off.

211

A. Sehirlioglu, A. Sayir, F. Dynys, “Doping of BiScO3-PbTiO3 Ceramics for Enhanced Properties,” J. Am. Ceram.
Soc., vol. 93, p 1718-1724, 2010.
212

E. A. Anton, W. Jo, D. Damjanovic, J. Rödel, “Determination of depolarization temperature of (Bi1/2Na1/2)TiO3based lead-free piezoceramics,” J. Appl. Phys., vol. 110, p. 094108 1-14, 2011.

Pb-free film processing
CLUB A
Wednesday, July 24 2013, 02:00 pm - 03:30 pm
Chair:Jon Ihlefeld
Sandia National Laboratories

ISAF2-H1-1 _____________________________________________________________________________________________________________________

Growth and size control of Bi4Ti3O12 nanowalls
and their piezoelectric property
Tomoaki Yamada1,2, Takaaki Shibata1, Koji Ishii3, Masahito Yoshino,1 Junichi Kimura4,
Hiroshi Funakubo4, and Takanori Nagasaki1
1

Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya, Japan
2
PRESTO, Japan Science and Technology Agency, Tokyo, Japan
3
Asylum Technology Co., LTD., Tokyo, Japan
4
Department of Innovative and Engineered Material, Tokyo Institute of Technology, Yokohama, Japan
Email: t-yamada@nucl.nagoya-u.ac.jp

Large piezoelectricity in ferroelectric materials attracts attentions for developing small energy
conversion devices such as micro actuators and energy harvesters. It has been theoretically andexperimentally shown that the piezoelectric response in the ferroelectric film is strongly suppressedas the film is mechanically clamped by the substrate. On the contrary, the nanostructure with large
aspect ratio (for instance, nanorod) can offer exceeding properties as such a clamping effect can beignored. So far, the fabrication of Pb(Zr,Ti)O3 nanorods by FIB213 and by self-assembled growth214
having enhanced piezoelectric property has been demonstrated; however, such nanostructures ofother ferroelectrics –especially, lead-free ferroelectrics– have been rarely reported. In thispresentation, we demonstrate the growth of size controlled Bi4Ti3O12 (BIT) nanowall structure byutilizing its growth anisotropy, and investigate their piezoelectric property.
BIT was epitaxially grown on TiO2(101) substrate215 with a(b)-axis orientation at different
temperatures and oxygen pressures by pulsed laser deposition. It was found that, by depositing BIT
at temperatures below 700 ºC, the nanowall-like structure was formed. As shown in Fig. 1, BIT
grew fast with a- and b-axes and slow with c-axis. Therefore, it can be said that the formation of the
BIT nanowalls is driven by the strong anisotropy of the growth rate of BIT. In addition, the width ofnanowalls decreased with decreasing the deposition temperature (Fig. 2), which implies that thesurface diffusivity of PLD species
Plane view
Cross section
plays a role in changing the width ofa(b)nanowalls. It was also found that theb(a)density of nanowalls can be effectivelyccontrolled by the oxygen pressurescduring the deposition.
Fig.1 SEM images of a(b)-axis oriented BIT deposited at 600 ºC and 200
mTorr O2.
550 ºC
600 ºC
700 ºC

Count

Count

The PFM phase (Fig.3) and amplitude(not shown here) of a BIT nanowallshow evident ferroelectric andpiezoelectric nature. The detailed
piezoelectric
property
and
the

213

J.-H. Li et al., Appl. Phys. Lett. 84, 2626 (2004).

214

T. Yamada et al., ISAF-PFM-2011, July 2011.

215

Fig.2 Width of BIT nanowall
T. Watanabe et al., Appl. Phys. Lett. 81, 1660 (2002).

0.0
0

0.1
0.1

0.2
0.2

0.3
0.3

Nanoplatewidth (
Width ofnanowall (µm)

deposited at 550, 600 and 700 ºC
under 200 mTorr O2.

0.4
m)

0.5

Fig.3 PFM phase of BIT nanowall
deposited at 600 ºC and 200 mTorr O2.

comparison with the different size of nanowalls are presented.

ISAF2-H1-2 _____________________________________________________________________________________________________________________

Processing and Ferroelectric Properties of undoped and Mn-dopedx[Bi0.5Na0.5TiO3]-(1-x)[Bi0.5K0.5TiO3]-(0.04) [Bi0.5Li0.5TiO3] Thin films
M. Hejazi, A. Safari
Glenn Howatt Electroceramics Laboratory
Department of Materials Science and Engineering, Rutgers University
607 Taylor Rd, Piscataway, NJ 08854
Lead free thin films with different compositions Bi0.5(Na0.76K0.2Li0.04)0.5TiO3 (BNKLT76)
and Bi0.5(Na0.88K0.08Li0.04)0.5TiO3 (BNKLT88) were deposited on SrRuO3 coated (001)-SrTiO3
substrates by pulsed laser deposition technique. The effects of oxygen pressure and Mn-doping on
the leakage current, ferroelectric and dielectric properties were investigated. It was found thatpolarization and permittivity of BNKLT76 composition is higher than those of BNKLT88 thinfilms. However, it suffers from high dielectric loss and leakage current. To improve the insulating
properties, ceramic targets were doped with 2 mol.% Mn. The remnant polarization and dielectric
constant (at 10 kHz) of Mn-doped BNKLT76 film deposited at 400 mtorr were measured to be 23µC.cm-2 and 660, respectively. The leakage current density of Mn-doped films was suppressed bymore than two orders of magnitude and the polarization was considerably enhanced. It was also
demonstrated that Mn doping decreases the dielectric loss without any adverse effect onpermittivity. The XPS results showed coexistence of Mn2+, Mn3+, and Mn4+ in doped-films.
Oxidation of Mn2+ to higher valence states by absorbing holes along with occupation of A-site
vacancies might be possible reasons for a reduced leakage current and dielectric loss in Mn-doped
films.

ISAF2-H1-3 _____________________________________________________________________________________________________________________

Bi-based Piezoelectric Thin Films via Chemical Solution
Deposition
Yu Hong Jeon1, Eric Patterson2, David P. Cann1, Peter Mardilovich3, William Stickle3, and Brady J.
Gibbons1
1

Materials Science, School of Mechanical, Industrial, & Manufacturing Engineering, Oregon State
University, Corvallis, OR 97331 (USA)2
Institute of Materials Science, Technische Universität Darmstadt, Darmstadt, 64287, Hesse,
Germany
3
Hewlett-Packard Corporation, Corvallis, OR 97330 (USA)
Email: brady.gibbons@oregonstate.edu

Strain [%]The highest performing piezoelectric materials include lead as a major constituent. Worldwide,
increased restrictions on the use of lead have resulted in a search for candidates to replace theselead-based piezoelectric materials. One promising material is the solid solution of (Bi0.5Na0.5)TiO3– (Bi0.5K0.5)TiO3 (BNT-BKT). Although promising behavior has been observed in bulk materials,
similar results have been elusive for BNT-BKT thin films. In this work, 0.8 BNT – 0.2 BKT thinfilms (near morphotropic phase boundary composition) were synthesized on platinized silicon
substrates via chemical solution deposition. Well-crystallized BNT – BKT thin films were grown atvarying processing conditions. Phase purity was confirmed by X-ray diffraction. As Bi, Na, and K
are volatile elements, overdoping of these cations (addition of excess cation precursors) was
introduced to compensate for volatilization during synthesis. Quantitative compositional analysis offilms was performed with electron probe microanalysis and compositional depth profiling toconfirm atomic ratios via X-ray photoelectron spectroscopy. The composition data from bothmeasurements were consistent and indicated stoichiometric films were achieved. Dependent on theoverdoping and annealing conditions, dense, smooth, crack-free films were achieved with relative
dielectric constants from 390 to 730 and low
0.6
BNT-BKT-BMgT
dielectric loss of 2 - 5% at 1 kHz. Additionally,
BNT-BKT-BMgT
0.5
PZT
maximum and remanent polarizations of 45 and 16
PZT
0.4µC/cm2, respectively, were recorded at 200 Hz. The
addition of Bi(Mg0.5Ti0.5)O3 (BMgT) was also
0.3
explored, as promising piezoelectric response (high0.2field d33 up to 600 pm/V) in bulk compositions has
0.1
been observed. BNT-BKT-BMgT thin films wereprepared, showing very promising piezoelectric0response with d33,f up to 75 pm/V and strain values up
-0.1
-500
-250
0
250
500
to 0.35%, as measured by double beam interferometry
Field [kV/cm](see Fig. 1, with values compared to typical Pb-based
thin films).216 Finally, Rayleigh analysis was Figure 62: Strain measurements of BNTcompleted on several Bi-based thin film compositions BKT-BMgT thin films compared to typicallead zirconate titanate (52/48) solution
derived thin films.

216

Y-H. Jeon, et al. “Large piezoresponse and ferroelectric properties of (Bi 0.5Na0.5)TiO3 – (Bi0.5K0.5)TiO3 –Bi(Mg0.5Ti0.5)O3 thin films prepared by chemical solution deposition,” J. Am. Ceram. Soc., in press.

to extract the intrinsic and extrinsic contributions to the dielectric properties.

ISAF2-H1-4 _____________________________________________________________________________________________________________________

Realization and characterization of manganese-doped BST thinfilms for reflect array applications
Hartmut W. Gundel1, Kevin Nadaud1, Caroline Borderon1, Sabrina Pavy1, Raphaël Gillard2
1

IETR, University of Nantes, Nantes, France
2
IETR, INSA of Rennes, Rennes, France
E-mail: Hartmut.gundel@univ-nantes.fr

Ferroelectric thin films are attractive materials for tunable microwave devices such as electricallytunable filters, reflect arrays, resonators or phase shifters. For this type of application, theferroelectric material should have an important tunability of the dielectric permittivity and low
dielectric losses. It is well known that the dielectric properties strongly depend on the material’s
microstructure and that they are particularly sensitive to existing defects. In perovskite typeferroelectric thin films, oxygen vacancies play an important role as these defects create conductionin the film and losses may be important; hence it becomes necessary to dope the film in order toreduce the influence of the defects.
Mn-doped Ba(1-x)SrxTiO3 (BST) thin films already have been realized by Chemical Solution
Deposition (CSD) on stainless steel substrates217 and the influence of its morphology on the
dielectric properties has been shown218. Ba(1-x)SrxTiO3 is a mixed compound of BaTiO3 and SrTiO3
which is widely studied because its Curie temperature depends on the ratio between barium andstrontium in the material. This allows tailoring the material for a use at room temperature either inthe ferroelectric or in the paraelectric phase.
In the present work, Mn-doped Ba0,80Sr0,20TiO3 (BST) thin films were realized by Chemical
Solution Deposition (CSD) on alumina as the foreseen application for a reflect array needs
integration of the ferroelectric on an insulating substrate. This allows utilization of the tunabledielectric permittivity in a CoPlanar Waveguide (CPW) technology.
In order to compensate the electrons released by the oxygen vacancies, we have studied manganese
doping which acts as an electron acceptor, substituting the titanium ions. As the optimum dopant
rate to be inserted depends on the material’s defect density, we have investigated BST doping witha manganese content ranging from 0% to 2%. The dielectric and electrical characteristics were
investigated as a function of Mn content in the frequency range of 100 Hz to 10 GHz Depending on
the expected application, a compromise between high tunability and low dielectric losses thus canbe established by using the appropriate amount of the dopant. .

217

C. Borderon, D. Averty, R. Seveno, H.W. Gundel, "Preparation and characterization of barium strontium titanate
thin films by chemical solution deposition", Ferroelectrics 362 (2008) 1-7
218

C. Borderon, D. Averty, R. Seveno, H.W. Gundel, "Influence of the morphology of Barium Strontium Titanate thinfilms on the ferroelectric and dielectric properties", Integrated Ferroelectrics 97 (2008) 12-19

ISAF2-H1-5 _____________________________________________________________________________________________________________________

Ferroelectric properties of ultrathin SrTiO3 films epitaxiallygrown on graphenePeter K Petrov1, Bin Zou1, Clementine Walker1, Ling Hao2, Edward Romans3, Arnaud Blois3,
Sergiy Rozhko3, Norbert Klein1, Olena Shaforost1, Cecilia Mattevi1, Neil Alford1
1

Department of Materials, Imperial College London, London SW7 2AZ, UK
2National Physical Laboratory, Teddington, TW11 0LW, UK
3
University College London, London WC1E 7JE, UK
Email: p.petrov@imperial.ac.uk

Graphene is attracting enormous scientific attention due to its unique properties e.g. electricalconductivity and optical transparency. It is considered as the successor of the costly ITO in large
scale and flexible displays.
In this study we investigated the properties of SrTiO3 (STO) thin films epitaxially grown ongraphene layers. Graphene layers were CVD grown on Cu foil and transferred to TiO2-terminated
STO substrates.
SrTiO3 layers with thicknesses varying from
10nm to 100 nm were deposited at a temperatureof 850 oC, and oxygen pressure ranging from0.01 mTorr to 300 mTorr using pulsed laser
deposition (PLD). The two-dimensional growthof the STO layer was monitored in-situ by
RHEED. To measure its electrical properties,
the STO film was covered with a 50 nm Au
layer using dc magnetron sputtering; and MIM
capacitor structures were formed with photolithography followed by ion-milling.

Fig. 63: RHEED oscillations observed during the
growth of the STO film on graphene layer. Eachmaximum represents a complete STO monolayer.

The surface of the STO film was analyzed using
AFM, while its crystal structure was examinedby x-ray, SEM and TEM. Results of theelectrical measurements carried out within atemperature range of 77K up to 100oC will bepresented.
The feasibility of detecting the change ofmagnetisation in such samples with a techniquesuch as SQUID-based microscopy will also be
discussed.

Fig. 2: Optical image of the MIM capacitor
structures formed on the top of thegraphene/STO/Au multilayer.

ISAF2-H1-6 _____________________________________________________________________________________________________________________

Solgel Hydrothermal Synthesis of BaTiO3/MWCNTs for Microelectronic Applications
Amit Mahajan1, Paula M. Vilarinho1, Angus Kingon2 and Ákos Kukovecz3,4
1

Department of Materials and Ceramic Engineering, CICECO, University of Aveiro, 3810-193
Aveiro, Portugal
2
Division of Engineering, Brown University, Providence, Rhode Island 02912, USA
3
Department of Applied and Environmental Chemistry, Faculty of Sciences, University of Szeged,
H-6720 Szeged, Hungary
and4
MTA-SZTE “Lendület” Porous Nanocomposites Research Group, 6720 Szeged, Rerrich Béla tér 1.
Email: paula.vilarinho@ua.pt
CNTs have a unique set of mechanical, chemical and electrical properties which make them very
promising for the development of nanostructures and nanocomposites. In particular the ballistic
electron transport and a huge current - carrying capacity, are of interest for the many future
microelectronics applications such as super capacitors, FET and memory cells 1. Therefore, carbon
nanotubes (CNTs) is an interesting option under consideration to be used as templates or bottom
electrodes for 3D structures and used as metal filler in polymer and/or Ferroelectric (FE) in order toimprove the electrical properties 2. In the last decades, efforts have been carried out in order tocover MWCNTs with various FE by physical vapor deposition and chemical methods to fabricate
3D capacitor structures 2-4. Covering CNTs with FE is not a trivial task and many aspects are still
unexploited and unclear. Therefore, in this work systematic studies were carried out for the
fabrication by a sol gel hydrothermal method of BT/MWCNTs composites and measurement ofelectrical properties.
Functionalized MWCNTs with HNO3 were used, having diameter and length around 10-35 nm and~10 µm, respectively. Barium titanate solution was prepared from barium acetate and titanium
isopropoxide precursor. In the BT solution, MWCNTs were dispersed for five minutes using ultrahigh -sonication followed by 2 h stirring. Potassium hydroxide solution was added in to BTMWCNTs solution, in order to precipitate BT. The precipitated slurry was transfer to the autoclave
and the hydrothermal reaction was carried out from 2 to 24 h and temperatures ranging from 100 to
250 ºC to obtained BT-MWCNTs composites. Pure BT powder was also synthesis using similar
process for comparison. The composite were characterized by XRD, FTIR, Raman and Electron
Microscopy for phase formation and morphology of the composites. The electrical properties were
measured using Piezo Force Microscope (PFM) and Impedance spectroscopy.

Novel Ferroelectric Devices
CLUB B
Wednesday, July 24 2013, 02:00 pm - 03:30 pm
Chair:

Glen Fox
Fox Materials Consulting

ISAF4-H2-1 _____________________________________________________________________________________________________________________

Planar Laser-Micro Machined Bulk PZT Bimorph
In-Plane Actuation

For

Sachin Nadig1, Serhan Ardanuç 2, Victor Haas3, Amit Lal41

Electrical And Computing Engineering, Cornell University, Ithaca, NY 14853,USA
Email: spn36@cornell.edu

In this work, we demonstrate a PZT bimorph technology for high level chip-scale nano-motion
actuator integration. Precision piezoelectric stages for linear and rotary motion have proven to be ofgreat value in areas that require accurate positioning and calibration. Ultrasonic motors andpiezoelectric actuators such as bimorphs, unimorphs and shear tubes are key elements of thesesystems. Bimorphs are the most commonly used actuators to maximize displacement. Most
bimorphs are macro scale, millimeters in thickness and centimeters in width and length, making it
unsuitable for integration in microsystems. Manual assembly of many of these large devices isrequired for large displacements and this does not lead to small systems. Alternatively, thin film
MEMS unimorphs and bimorphs use microns of piezoelectric material (PZT, AlN, ZnO) thatgenerally produce out of plane motion. A miniature bimorph technology that enables manybimorphs to be placed in precision and provide lateral in-plane motion, with single direction ofpolarization is not available. In this work, we present experimental results on a bimorph fabricatedfrom bulk PZT 4H by laser cutting of PZT plates.
The actuators were fabricated using a commercial laser cutting tool to define beams by cutting
entirely through the PZT plate. The laser cutting tool is also used to define arbitrary twodimensional electrode patterns on the PZT beam. A 10mm long, 0.45mm wide and 0.5mm thickPZT 4H actuator was tested with actuation capabilities of ~ 0.08µm/V for single side and ~0.18µm/V for double sided electrode patterns. Figure 1 shows the process flow and the fabricatedbimorph.
Our demonstrated actuator can be useful in low-cost miniature precision nano-motion stages for
manipulating MEMS devices. The laser cutting enables a repeatable, high-throughput fabrication
process, which creates devices that are capable of larger displacements than conventional bimorphs.
While we demonstrate the process on a planar bimorph structure, this also allows fabrication of 3D
piezoelectric actuators with arbitrary electrode patterns, allowing engineering of complex
displacement profiles.

(a)

P

PZT 4H plate

Laser Cutting

Top Electrode
Patterning

Process Bottom

Bottom Electrode
Patterning

Cross Sectional View

(b)
10mm

Fig 1 (a) Shows the process flow used for fabricating the Bulk PZT bimorphs. Fig 1 (b) shows the image of thefabricated 10mm long 0.45mm wide and 0.5mm thick bulk PZT bimorph for in-plane actuation.

ISAF4-H2-2 _____________________________________________________________________________________________________________________

Improvement of the Stability of X-ray Emission
by the Thermal Excitation of Pyroelectric Crystals
Fumihiko Naruse1, Hiroyuki Honda1, Yoshikazu Nakanishi1,
Shinji Fukao1, Yoshiaki Ito2, Yuuki Sato1, Shinzo Yoshikado1
1
Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto, Japan
2
Institute of Chemical Researches, Kyoto University, Uji, Kyoto, Japan
Email: syoshika@mail.doshisha.ac.jp

Fig. 1 shows the energy spectra of X-rays per period with
one crystal for L = 1000 s. Fig. 2 shows the average countrate of photons of Cu Kα X-rays with six crystals for L =

219

10

Cu K Cu K

4Ta L 

10
10

2

1 crystal
Heating
Cooling

Noise

0

0

10

20 30 40
Energy [keV]50

Fig. 1: Energy spectra of X-rays
per period for L = 1000 s.
Average countrate [cps]Nonstoichiometric LiTaO3 single crystals were used. In thecase of one crystal, a round copper foil of 20 μm thickness asa target was placed at 15 mm above the negatively charged
surface (–z surface) of the crystal in a chamber made fromstainless steel. In order to supply electrons, a conventional
tube-type X-ray source (Amptek Mini-X) was attached to thechamber and aluminium plate of 10 mm square and 2 mm
thickness as an electron source was placed near the crystal.
The tube voltage was 30 kV. The crystal temperature wascontrolled by the application of triangular voltages to thePeltier device. The temperature range ΔT, was fixed at
approximately 30 or 40°C. The temperature change period L,
and the tube current I, were varied. The ambient gas was air
and the pressure in the chamber was approximately 10-4 Pa.
X-ray emission was measured using a Si-PIN X-ray detector.

Intensity [counts]

A miniaturized X-ray source based on a pyroelectric crystal can be used in portable analytical
instruments such as portable X-ray fluorescence spectrometers. The X-ray emission for a long timerequires the crystal temperature to be periodically changed to form intense electric fields. Therefore,
X-ray is emitted discontinuously. Continuous emission can be achieved by using multiple crystals
and changing their temperatures with appropriate phase differences219, however, the X-ray intensity
is still unstable. When the net amount of charge exceeds a certain threshold, electrostatic creeping
discharge occurs along the crystal surface and the X-ray emission suddenly ceases. To avoid such
discharge, the initial amount of electric charge on a crystal for each temperature cycle must be
equal. It is suggested that the amount of accumulated charges on the surface is dependent on thepressure of ambient gas, amount of electrons supplied, and period of the temperature cycle. In thisstudy, the stability of the X-ray emission using one or six crystal(s) was investigated by changing
the temperature cycle period. Furthermore, in order to investigate the contribution of the electrons
to the stabilization, electrons were supplied to the space between a crystal and a target using thephotoelectric effect using a conventional tube-type X-ray source.

103

6 crystals

10
10
10

2

L = 1000 s
L = 2000 s

1

0

0

20

40 60 80
Period number

100

Fig. 2: Average count rate ofphotons of Cu Kα X-rays for
L = 1000 and 2000 s.

H. Honda et al., “Evaluation of Compact X-ray Source Using Multiple LiTaO3 Single Crystals”, Key Eng. Mater.,vol. 485, p. 295-298, 2011.

1000 and 2000 s. The long-term stability of the X-ray emission was significantly changed when L
was varied.

ISAF4-H2-3 _____________________________________________________________________________________________________________________New Cooling Technologies based on the Electrocalorics
Brigita Rožič1,2, Zdravko Kutnjak1,2,3, George Cordoyiannis1,2,4, Maja Trček1, Hana Uršič1,2, Jurij
Koruza1,2,3, Marko Vrabelj1,3, Barbara Malič1,2,3, Raša Pirc1, S.-G. Lu5, Qiming M. Zhang51Jožef Stefan Institute, Jamova cesta 39, 1001 Ljubljana, Slovenia
Centre of Excellence Namaste, Jamova cesta 39, 1001 Ljubljana, Slovenia
3Jožef Stefan International Postgraduate School, Jamova cesta 39, 1001 Ljubljana, Slovenia
4
Department of Physics, University of Athens, 15784 Athens, Greece
5
Material Research Institute, the Pennsylvania State University, University Park, PA 16802, USA
2

Email: brigita.rozic@ijs.si
Electrocalorics, materials that exhibit a temperature change under the adiabatically applied/removed
electric field, i.e., the electrocaloric effect (ECE), are very important for more energy efficient andenvironmentally acceptable technologies. An increasing interest in the research of these materials
has been revived recently by the predictions of the giant electrocaloric response in some inorganicand organic materials220,2.
The electrocaloric materials are, in comparison to thermoelectric or magnetocaloric materials, good
insulators and because of miniaturization possibilities they are very promising for different
applications including household refrigerators, sensors, actuators, heat pumps, devices for coolingmicroelectronic components, applications in microrobotics, etc.
In this presentation a review of our direct measurements of the ECE in various inorganic andorganic bulk, thick and thin films such as relaxor ferroelectric ceramics including PMN, PMN-PT,
PLZT, KNN-STO, and thin films of normal ferroelectric and relaxor ferroelectric polymers, i.e.,P(VDF-TrFE)-based terpolymers, copolymers and various blends3,4 will be given. Observed
magnitudes of the ECE confirm existence of the large electrocaloric effect in these systems and it
was also shown that in bulk relaxor ferroelectrics the ECE behaviour determined from the direct
measurements is in a good agreement in the vicinity of the critical point with the theoreticalpredictions5.
Acknowledgment:
The contribution of Prof. Marija Kosec who passed away in December 2012 is gratefully
acknowledged.

220

A. S. Mischenko et al., “Giant electrocaloric effect in thin-film Pb0.95Ti0.05O3”, Science, vol. 311, p. 1270-1271,
2006.

2

B. Neese et al., “Large electrocaloric effect in ferroelectric polymers near room temperature”, Science, vol. 321, p.
821-823, 2008.

3

S.-G. Lu et al., “Organic and inorganic relaxor ferroelectrics with giant electrocaloric effect”, Appl. Lett. Phys., vol.
97, 162904, 2010.

4

B. Rožič et al., “Influence of the critical point on the electrocaloric response of relaxor ferroelectrics”, J. Appl. Phys.,vol. 110, 064118, 2011.

5

R. Pirc et al., “Electrocaloric effect in relaxor ferroelectrics”, J. Appl. Phys., vol. 110, 074113, 2011.

ISAF4-H2-4 _____________________________________________________________________________________________________________________

Photopyroelectric breakdown in Mg-doped LiTaO3 crystal
at second harmonic generation1

Kenji Kitamura1,2, Hideki Hatano1,2, Oleg A. Louchev3 and Satoshi Wada3
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
2
SWING Ltd. Tsukuba, Ibaraki 305-0033, Japan
3
RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
Email:KITAMURA.Kenji@nims.go.jp

Periodically poled ferroelectric crystals such as LiNbO3 (LN) and LiTaO3 (LT) are widely used for avariety of laser frequency conversion processes. The theory of nonlinear optical conversion allows
reliable efficiency prediction under low intensities. Under high intensities additional effects are involved
inhibiting non-linear conversion: two-photon absorption and multi-photon absorption resulting inelectron generation into conduction band, heating, harmonics wave vectors mismatch, lensing, anddefects generation many of which can be taken into
account by performing rigorous computer simulations.
However, the theory of optical discharge andconsequent damage in dielectrics is often disagrees with
the numerous empirical observations and continues toremain in the focus nonlinear optics research closelycooperating with the actively explored fields of lasermatter interactions, laser ablation, laser opticalproperties modification and recording in dielectrics.
It is generally accepted that in laser-matter Fig. 1: Experiment and simulation ofinteraction the electrons absorbing energy from the
SHG efficiency vs W in PPS LT showradiation dissipate this energy to the lattice and theing material damage at the input FH
equilibrium is established for laser pulses extending
2
longer than the electron-to-lattice energy transfer time. pulse power density, W=300 MW/cm
We show that additionally to this process an opposite
lattice-to-electron energy transfer takes place innonlinear crystals providing an effective kinetic pathway fordischarge during laser frequency conversion.
In particular, we conclude that in the experiments for SHG
of 532 nm radiation using a periodically poled SLT crystal thedischarge and damage are due to the following mechanism: (i)Fig. 2: Structural damage close
the photo-absorption increase during SHG1 at the back side ofto the output face of SLT SHG
the crystal induces (ii) an initial temperature increase of ≈1-1.5
K in non-symmetric crystal lattice leading to (iii) a high device left by 5 series ofgradient of the spontaneous polarization across the irradiated experiments.
zone and (iv) to the onset of high electric field, ≈104 V/cm,
enabling (v) acceleration of free electrons generated by resonant two-photon absorption to the energy,≈10-20 eV ( the critical value corresponding to the impact generation of electrons from the valence bandin LT is ≈1.5Eg ≈6.9 eV), followed by (vi) the impact ionization and structural damage of operating
crystal.
1

LO.A.Louchev, N-E, Yu, S. Kurimura, K.Kitamura, Appl. Phys. Lett. 87 131101 (2005).

ISAF4-H2-5 _____________________________________________________________________________________________________________________

Photoconductivity from Electrospun Bismuth Ferrite Nanofibers
R. Rivera, R. Kappera, M. Chhowalla and A. Safari
Department of Materials Science and Engineering
Rutgers, The State University of New Jersey, New Jersey, USA
Email: rutri10@eden.rutgers.edu

Bismuth ferrite (BFO) has attracted great attention not only because it is potential applications as
multiferroic material in the spintronics, and micro-electromechanical area but also because it isphoto-electronic behavior in energy harvesting field. Regardless the great interest on BFO for
ferroelectric applications there are only few studies on the photoconductivity of this material. In
this investigation we report the observation of photoconductivity from multiferroic BFO nanofibers
whose photo response varies with the diameter of the nanofiber. Bismuth ferrite nanofibers were
deposited on oxidized silicon and quartz substrates using sol-gel based electrospinning technique.
The thickness of the fibers was well controlled by varying the molarity ratio of the precursor
solution. X-ray photoelectron spectroscopy (XPS) results showed a combination of Fe3+ and Fe2+
valence states in the fibers. Rutherford backscaterring spectroscopy (RBS) result showed astoichiometry composition after heat treatment. Both scanning electron microscopy (SEM) andatomic force microscopy (AFM) images revealed that the fibers structure is uniform in diameters
ranging from of 15 to 100nm and several microns in length as well. Photoconductivity
measurements show considerable increase in the current flowing through the fibers when measured
under illumination. This photoresponse behavior is almost hundred times higher for a fiber of 50nm
diameter than for a fiber of 15nm.
recombination mechanism.

This effect is described by a size dependent surface

ISAF4-H2-6 _____________________________________________________________________________________________________________________

Application of PIN-PMN-PT:Mn in High-Performance Flame
Detectors
A. Movchikova1, N. Neumann1
1

InfraTec GmbH, Gostritzer Str. 61-63, 01217 Dresden, Germany
Email: a.movchikova@infratec.deFerroelectric relaxor-PbTiO3 single crystals were reported to be themost promising candidates for pyroelectric applications, because of
their ultra-high pyroelectric coefficient and relatively low dielectricloss221. In our previous works was shown that PMN-0.26PT:Mn
and PMN-0.29PT:Mn crystals, outperforms LiTaO3 (LTO) crystals
in pyroelectric detectors by a 3 times higher specific detectivity222.
Unfortunately, rhombohedral PMNT single crystals exhibit low
phase transition temperatures (TRT≈100°C), which limit the Fig. 1: Pyroelectric
processing temperature during fabrication and also the operating detector based on
temperature range. Therefore, more attention is focused on the PIMNT
ternary solid solution system xPIN-yPMN-(1-x-y)PT, PIMNT wich
is distinguished by a higher Curie temperature223. In this work the suitability of Mn-doped 0.26PIN0.42PMN-0.32PT single crystals in single and quad channel flame detectors was evaluated andcompared with standard LTO.
The phase transitions, dielectric and pyroelectric properties of rhombohedral phase [111] oriented
0.26PIN-0.42PMN-0.32PT single crystals were investigated. InfraTec’s detector design PIE-205
operating in current mode were used for the evaluation. In addition detectors based on LiTaO3 wereprepared for an easier comparison. Responsivity and noise of both detectors were measured in thefrequency range 0.1 Hz – 10 kHz at room temperature. The specific detectivity was calculated fromsignal and noise measurements (Table 1).
The evaluation shows that also Mn doped PIN-PMN-PT based detectors outperform the standard
LiTaO3 based detectors especially in the low frequency range of 1-10 Hz. Based on this basic
design a new generation of high-performance long-range flame detectors will be established.
Table 1: Material properties and detector performance of PIN-PMN-PT, LiTaO3 single crystals
Pyroelectric Detectormaterial
Type
PIMNT
LT

PIE-205
LIE-205

Element
Size
mm2
2.0 x 2.0
2.0 x 2.0

Thickness
µm
33
24

tanδ

TRT

TC

µC/m²/K (1 kHz) (1 kHz)730
525 0.0003
175
43.5 0.0001

°C
125
-

°C
181
603

p

εr

D* (500 K, 10 Hz,
BW 1Hz, 25°C)
cmHz1/2/W

9.5 x 108
3.6 x 108

221

Y. Tang. “Large pyroelectric response in relaxor-based ferroelectric (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 single crystals”,
J. Appl. Phys.,vol. 98, 084104, 2005
222

N. Neumann, M.Es-Souni, H.Luo. “Application of PMN-PT in pyroelectric detectors”, Proc ISAF-IMF-2009,
August 23-29, 2009, Xi´an, China.
223

N. Yasuda. “Crystal growth and electrical properties of lead indium niobate-lead titanate binary single crystal”, J.
Cryst. Growth, vol. 229, p.299-304, 2001.

Capacitors
CLUB C
Wednesday, July 24 2013, 02:00 pm - 03:30 pm
Chair:

Satoshi Wada
University of Yamanashi

ISAF4-H3-1 _____________________________________________________________________________________________________________________The effects of Sn2+ ion doping on perovskite titanates
Shoichiro Suzuki1, Atsushi Honda,1 Naoki Iwaji,1 Shin’ichi Higai,1 Akira Ando1
1

Murata Manufacturing Co., Ltd. 1-10-1 Higashikotari, Nagaokakyo, Kyoto 617-8555, Japan
Email: shoichiro_suzuki@murata.co.jp

It is well known that ferroelectric perovskite titanates (ATiO3) are important materials for applied
electronics industries. The substitution of Sn2+ ions into the A sites of the perovskite lattice has
recently been a subject of intensive research, because this is a promising approach for the
fabrication of Pb-free ferroelectric materials.1 However, the synthesis of ferroelectric ATiO3 ofwhich A sites are substituted with Sn2+ ions has been found to be difficult from several studies.2
In recent studies, we have fabricated Sn2+ and Ca2+ codoped
BaTiO3 (BT) ferroelectric ceramics and examined their
thermal and dielectric properties. As a result, the Sn2+ andCa2+ codoped BT ceramics exhibited a higher Tc than Sn
non-doped and Sn4+ doped ceramics.3-4 We also found that
decreasing the perovskite lattice size by Ca2+ doping iseffective for Sn2+ substituting into Ba site of BT with an aid
of first principle theoretical calculations.5 Moreover, aspherical aberration corrected scanning transmission electron
microscope observation revealed that Sn ions exist at Ba
sites.6 From these results, we concluded that Sn2+ ionssubstitution into Ba sites enhanced the ferroelectricity of BT. Fig. 64: Tmax for SrTiO3 ceramics as afunction of doping concentration x.
On the other hand, we have studied the effects of Sn2+ ion
doping on the properties of another perovskite material
SrTiO3 (ST). Here, we compare the effects of Sn2+ ion doping on ST with other element such as Pb.
The relationship between Tmax and doping concentration x is shown Figure.1 where Tmax is atemperature which gives maximum dielectric permittivity. Circles represent the Sn doping of ourstudy and solid line represents Pb doping reported by Lemanov et al.7 Tmax is increasing withincreasing for both the cases of Sn and Pb. Interestingly, Tmax of Sn doped ST is much higher than
the Pb doped one. We consider that the difference of increasing Tmax originates from the ion size
difference between Sn2+ and Pb2+. Smaller Sn2+ ion prefers to locate the off-center position rather
than remaining center position, thus it introduce a stronger local dipolar distortion around Sr sitethan that caused by Pb doping. The cooperation forces between the stronger local dipoles by Sn2+
doping keeps ferroelectricity at high temperatures.
1

Y.Uratani, T.Shishidou and T.Oguchi, Jpn. J. Appl. Phys. 47, 7735 (2008).

2

S.Matar, I.Baraille and M.Subramanian, Chem. Phys. 355, 43 (2009).

3

S.Suzuki, T.Takeda, A.Ando and H.Takagi, Appl. Phys. Lett. 96, 132903 (2010).

4

S.Suzuki, T.Takeda, A.Ando, T.Oyama, N.Wada, H.Niimi and H.Takagi, Jpn. J. Appl. Phys. 49, 09MC04 (2010).

5

S.Suzuki, A.Honda, S.Higai, A.Ando, N.Wada, and H.Takagi, Jpn. J. Appl. Phys. 50, 09NC11 (2011).

6

S.Suzuki, N.Iwaji, A.Honda, S.Higai, N.Wada, A.Ando and H.Takagi, Jpn. J. Appl. Phys. 51 (2012) 09LC08.

7

V.V.Lemanov, E.P.Smirnova and E. A.Tarakanov, Phys. Solid State 39, 628 (1997).

ISAF4-H3-2 _____________________________________________________________________________________________________________________

Lead free LTCC/PZT modules (LPM)
Markus Flössel1,2, Sylvia Gebhardt2, Andreas Schönecker2, Alexander Michaelis1,2
1

TU Dresden, Institute of Material Science, Chair of Inorganic Non-Metallic Materials, 01062
Dresden, Germany
2
Fraunhofer IKTS, Winterbergstraße 28, 01277 Dresden, Germany

e-mail: markus.floessel@ikts.fraunhofer.de

The combination of multilayer- and piezo-technology by laminating fired lead zirconate titanate(PZT) ceramic discs with low temperature cofired ceramics (LTCC) green layers and subsequently
sintering of the package yields to the so-called LTCC/PZT modules (LPM), which were firstpublished in 2010224.
The design of the LPM can be modified and it can so be used in two different cases of application.
On one side it is used as sensor/actuator module which is metal die casted in an aluminumcomponent and it controls the dynamic properties (vibration damping) of thin walled devices.
Besides with this metal die casting step, batch production by combining fabrication of mechanicalcomponents and integration of LPM in one production chain is possible. Then again it can also be
used as an ultrasonic transducer for Structural Health Monitoring (SHM) which permanently
monitors the health and condition of components used in rotorcraft, aircraft, pipelines, automobiles
et cetera.
This presentation will give an overview on technological challenges and their solution of producing
LPM and have a look of material properties and interactions especially chemical reactions in thephase boundary of LTCC and PZT which is necessary to fabricate functional microsystems.
Regarding to the directive of the European Union 2002/95/EG and 2011/65/EU which means
restriction of the use of certain hazardous substances (RoHS) conform components, we firstdeveloped lead free LPM and show properties of low-level signals and ferroelectric hysteresis
loops.

224

Flössel, M.; Gebhardt, S.; Schönecker, A.; Michaelis, A.: Development of a Novel Sensor-Actuator-Module with
Ceramic Multilayer Technology, In: Journal of Ceram. Sci. Tech., 01[01]55-58, 2010

ISAF4-H3-3 _____________________________________________________________________________________________________________________

Pulsed discharge behavior of (Bi0.2, Ba0.8)(Zn0.1, Ti0.9))O3 -based
relaxor multilayer ceramic capacitors
Harlan J. Brown-Shaklee, John J. Borchardt, Mia A. Blea and Geoff L. Brennecka
Material Science and Engineering Center, Sandia National Laboratories,
Albuquerque, New Mexico, USA
Email: hjbrown@sandia.gov

Reduction of permittivity with increased electric field is a phenomenon known as voltage tuning
and limits the energy density that many commercial ceramic capacitors can achieve. Using DC
fields up to 3kV, small signal permittivity was determined from impedance data and compared tolarge signal permittivity derived from P-E loops. The Bi(Zn½Ti½)O3-0.8BaTiO3 (BZT-BT)
dielectrics maintained high permittivities (k>1000) at fields greater than 100 kv/cm in contrast tocommercial dielectrics that fell to k~600 at half the field. This combination of high permittivity andbreakdown strength resulted in energy densities of >1.3 J/cm3 and makes the BZT-BT family of
dielectrics attractive for high-energy density multilayer capacitors. We will present the electricalproperties of 220nF BZT-BT multilayer ceramic capacitors (MLCC) designed to withstand >1500
volts. Until recently, the time domain response of this new relaxor system was not evaluated. Here,
we developed low inductance circuits to evaluate the time domain response of our 220nF multilayer
ceramic capacitors (MLCCs) comprised of BZT-BT dielectrics. These circuits were able todischarge the 220nF MLCCs with <80ns rise times while providing the means to evaluate the timedependent current. The nanosecond time domain signal
collected during pulsed discharge
was
used
to
determine
capacitance of the MLCCs as afunction of temperature andcharge voltage. We will showthatcapacitancevaluescalculated from the time domain
signals using RLC circuit models Figure 65. a) Pulsed discharge data collected from a 220nF BZT-BT
agree well with high frequency MLCC. The inset shows the circuit board used to measure the time
domain response. b) Capacitance measured in the frequency and time
capacitance values derived from domains with the time domain response having a characteristic circuit
frequency domain impedance frequency of 2.8 MHz and exhibiting the same temperature dependentdata.
frequency response that is characteristic for relaxor dielectrics.

This work was supported through the Energy Storage Program managed by Dr. Imre Gyuk of the Department ofEnergy’s Office of Electricity Delivery and Energy Reliability. Sandia National Laboratories is a multi-programlaboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation,
for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

ISAF4-H3-4 _____________________________________________________________________________________________________________________

Free-Electron Gas at Charged Domain Walls in Ferroelectrics
Sluka Tomas1, Tagantsev Alexander1, Bednyakov Petr1, Setter Nava1
1

Ceramics Laboratory, EPFL Swiss Federal Instituteof Technology, Lausanne, CH-1015 Switzerland
Email: Tomas.Sluka@epfl.ch

Solid interfaces between two distinct materials or material states are quasi two-dimensional objects withuniquely distorted electronic structures and ionic displacements. Properties of such interfaces may
therefore be entirely different from those of the parent materials. Indeed, technologically enticing
phenomena were found at hetero-interfaces between metal oxides225,226 and at compositionallyhomogeneous interfaces such as ferroic domain walls227. The latter are especially attractive for theirnaturally guaranteed high quality andmutability of their positions, shapes andintrinsic properties which could be utilized
inside a ready device228.
Unique properties are theoretically
predicted at ferroelectric domain walls
which form head-to-head and tail-to-tailpolarization divergences229,230 (Fig. 1). The
stabilization of these “strongly” charged
domain walls (sCDW) depends vitally
upon almost perfect compensation ofbound charge by free carriers (if not bycharged defects) and on ferroelastic
clamping. The compensation, in theory,
leads to formation of quasi-twodimensional free-electron (or hole) gas
analogically to the polar catastrophe
known at hetero-interfaces.
Here we show this phenomenon
experimentally in sCDW of the
prototypical ferroelectric BaTiO3. Their
giant steady metallic-type conductivity
evidence the presence of stable degenerate
electron gas.

225

Fig. 66: Free carrier concentration and band bending at
sCDW. (a) A periodic structure of 90° sCDW where boundpolarization charge ( + , − ) is almost perfectly compensatedby free carriers. (c) The band bending induced by boundcharge causes that the edges of the conduction EC or valence
EV bands (solid black lines) approach the Fermi level EF(dashed black line) where high concentration of free electrons(red line) or holes (blue line) are generated.

226

A. Tsukazaki et al., “Quantum Hall effect in polar oxide heterostructures”, Science, 315, 2007.
J. Mannhart et al., “Oxide Interfaces-An Opportunity for Electronics”, Science, 327, 2010.

227

J. Seidel et al., “Conduction at domain walls in oxide multiferroics”, Nat. Mater., 8:229, 2009.

228

G. Catalan et al., “Domain wall nanoelectronics” Rev. Mod. Phys., 84:119, 2012.

229

B. M. Vul et al., “II. Encountering domains in ferroelectrics”, Ferroelectrics, 6:29, 1973.

230

M. Y. Gureev et al. “Head-to-head and tail-to-tail 180 degrees domain walls in an isolated ferroelectric”. Phys. Rev.
B, 83, 2011.

ISAF4-H3-5 _____________________________________________________________________________________________________________________

Electrical and Thermal Properties of Polymer Systems With
Coexisting Ferroelectric and Relaxor States
Goran Casar1, Xinyu Li2, Jurij Koruza1, Qiming Zhang2, and Vid Bobnar1
1Jožef Stefan Institute and Jožef Stefan International Postgraduate School, Jamova 39, SI-1000
Ljubljana, Slovenia
2
Department of Electrical Engineering and Materials Research Institute, The Pennsylvania State
University, University Park, Pennsylvania 16802, USA
Email: goran.casar@ijs.si
Electroactive ferroelectric and, particularly, relaxor polymers based on poly(vinylidene fluoridetrifluoroethylene) copolymer, P(VDF-TrFE), are of great interest for a broad range of applications
as they exhibit giant electrostriction231, fast response speeds, high dielectric constant and highelectric energy density232, and large electrocaloric effect233. Up to now, however, most of theinvestigations have focused on either normal ferroelectric polymers or polymers that are completelytransformed into a relaxor, i.e., (i) terpolymers where the long-range ordering of polymer chains isbroken by introduction of additional monomers that contain large chlorine atoms or (ii) P(VDFTrFE), irradiated with high-energy electrons using relatively high doses234.
Here we report dielectric, calorimetric, and electrocaloric investigations of P(VDF-TrFE)
copolymer, irradiated also with low and moderate doses of high-energy electrons. While theferroelectric copolymer is completely transformed into a relaxor system at high irradiation doses,
dielectric investigations, particularly nonlinear dielectric experiments, i.e., the temperaturedependences of the second and the third harmonic dielectric response, clearly evidence that at lower
doses ferroelectric and relaxor states coexist in the P(VDF-TrFE) system235. This coexistence isconfirmed by the differential scanning calorimetry, which further reveals the influence of irradiationon the copolymer crystallinity and melting point. Finally, it is shown and explained that large
electrocaloric response of VDF-TrFE-based polymers is further enhanced in systems withcoexisting relaxor and normal ferroelectric states.

231

Q. M. Zhang et al., “Giant electrostriction and relaxor ferroelectric behavior in electron-irradiated poly(vinylidene
fluoride-trifluoroethylene) copolymer”, Science, vol. 280, p. 2101-2103, 1998.
232

B. Chu et al., “A dielectric polymer with high electric energy density and fast discharge speed “, Science, vol. 313, p.
334-336, 2006.
233

B. Nesse et al., “Large electrocaloric effect in ferroelectric polymers near room temperature”, Science, vol. 321, p.
821-823, 2008.
234

V. Bobnar et al., “Dielectric properties of relaxor-like vinylidene fluoride-trifluoroethylene-based electroactive
polymers”, Macromolecules, vol. 36, p. 4436-4442, 2003.
235

G. Casar et al., “Electrical and thermal properties of vinylidene fluoride-trifluoroethylene-based polymer systemwith coexisting ferroelectric and relaxor states”, submitted.

ISAF3G: Pb-based materials: Films
CLUB A
Wednesday, July 24 2013, 04:30 pm - 06:00 pm
Chair:

Brady Gibbons
Oregon State University

ISAF3-I1-1 ______________________________________________________________________________________________________________________

Flexoelectric Effects in Compositionally Graded FerroelectricThin Films – Towards Strain 2.0
Lane W. Martin1
1

Department of Materials Science and Engineering and Materials Research Laboratory, University
of Illinois, Urbana-Champaign, Urbana, IL, USA
Email: lwmartin@illinois.edu

In ferroelectric thin films, the utilization of epitaxial strain has enabled researchers to exact
dramatic control over the structure and properties of ferroelectrics. Modern manifestations offerroelectric thin films, including bilayer and superlattice heterostructures, have also provided
access to exotic structures and properties. In this presentation, we explore an alternative method bywhich we can tune the ferroelectric properties, namely compositionally graded hetero-structures,and how these structures can push the edge of strain control of materials.
Compositionally graded thin films possess a smooth variation in the composition throughout the
thickness of the film. We will discuss the evolution of crystal and ferroelectric domain structure aswell as the dielectric, piezoelectric, pyroelectric, and ferroelectric properties of compositionally
graded versions of PbZrxTi1-xO3 (PZT), Ba1-xSrxTiO3 (BSTO), and other common ferroelectric
systems. In the PZT system, for example, we will focus on compositions between the two endmembers PbZr0.2Ti0.8O3 (tetragonal, lattice parameters a = 3.94 Å and c = 4.12 Å) and
PbZr0.8Ti0.2O3 (rhombohedral, lattice parameter a = 4.118 Å and  = 89.73º). Using pulsed-laser
deposition, we have synthesized various thicknesses of films on a range of substrates and have
explored a number of sample variants including: single-layer, bilayer, and compositionally graded
heterostructures.
Extensive X-ray diffraction and piezoresponse force
microscopy studies have been completed on all sample
variants. Among the most surprising results are the factcertain versions of bilayer and compositionally graded
heterostructures are found to be nearly coherently strained
to the substrate (despite nearly 4% lattice mismatch) andthat these films exhibit unexpected crystal and domain
structures (e.g., tetragonal versions of PbZr0.8Ti0.2O3) [Fig.
1]. Subsequent studies of the properties of these films
reveal dramatically reduced permittivity (as low as 90 for
certain compositionally graded films), large remnant
polarizations, and horizontally shifted hysteresis loops(indicating the presence of a built-in electric field as large
as 200 kV/cm). These effects are the result the coupling
between the polarization and strain gradients in the film (orflexoelectricity). We will highlight how we can generatestrains as large as ~4.5x105 m-1, produce exotic properties Fig. 1: Reciprocal space mappingand susceptibilities, and the potential of compositionally about the 103 and 332-diffraction
graded films as a powerful new tool to tune the properties conditions and Piezoresponseof ferroelectric thin films towards Strain 2.0.
force microscopy images of (a)compositionally up-graded, and(b) down-graded heterostructure.

ISAF3-I1-2 ______________________________________________________________________________________________________________________

Ferroelastic Domain Wall Motion in PZT Thin Films
Raegan L. Johnson-Wilke1, Rudeger H.T. Wilke1, Margeaux Wallace1, Giovanni Esteves2, Jacob
Jones2, Susan Trolier-McKinstry1
1
The Pennsylvania State University, Department of Materials Science and Engineering, University
Park, PA, USA
2
University of Florida, Department of Materials Science and Engineering, Gainesville, FL, USA
Email: rlj12@psu.edu
Lead zirconate titanate (PZT) thin films are used in microelectromechanical systems (MEMS) due
to their large piezoelectric response. The electromechanical response in PZT is a result of both the
intrinsic (lattice) piezoelectric effect as well as the motion of ferroelectric and ferroelastic domain
walls (extrinsic effect). The work presented will describe an in-situ technique used to directly
measure the extent of ferroelastic domain wall motion as well as lattice strain in 2 μm thick PZT(30/70) films with different crystallographic textures. Synchrotron X-ray diffraction was used tomonitor the main Bragg peaks while subjecting the film to an applied electric field. Relativechanges in intensity between 200 and 002 peaks were measured. It was found that both the {001}oriented and randomly oriented films exhibited a significant amount of ferroelastic domain wallmotion during applied voltages above and below the coercive field. The effect is illustrated in the
figures below showing an increase in intensity in the 002 peak and a corresponding decrease inintensity in the 200 peak as the applied electric field is increased. This indicates that the volume
fraction of 002 domains increased under the application of an electric field. The piezoelectriccoefficient, d33, was calculated using X-ray diffraction by measuring peak shifts in primary Braggreflections. Upon examination of the shift in the 111 Bragg peak, the intrinsic component of d33 wascalculated to be ~50 pm/V for the {001} oriented 30/70 film. This value will be compared to values
measured using a double beam interferometer.
{001} oriented PZT film

Randomly oriented PZT film

50000

8000
0V
10 V
20 V
30 V
40 V

40000
30000
20000

PZT 002

10000
0
1.95

2.00

2.05
2.10
d-spacing (Å)

2.15

7000

Intensity (arb. units)

Intensity (arb. units)PZT 200

0V
34 V
51 V
68 V
85 V

PZT 200

6000
5000
PZT 002

4000
3000
2000
1.95

2.00
2.05
d-spacing (Å)

2.10

Figure: X-ray diffraction pattern near the 002 and 200 peaks in a PZT {001} oriented film (left) and a randomly
oriented PZT film (right). The fact that the 002 peak shows an increase in intensity as a function of applied voltage
indicates that the volume of 002 domains is increasing in the films as a function of electric field.

ISAF3-I1-3 ______________________________________________________________________________________________________________________

Characterization of GHz electromechanical properties of PZT
single crystalline thin films without removing substrate
Takahiko Yanagitani1, Masashi Suzuki1, KiyotakaWasa2
1

Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
2
Micro-Engineering, Kyoto University, Kyoto, Japan
Email: yana@nitech.ac.jp

Single crystalline (SC) PZT has attracted interest for high Q resonator and tunable filters. However,bulk SC-PZT near MPB can not be grown, and therefore the most common approach to obtain SC-PZT
is epitaxial growth technique. General epitaxial substrate: SrTiO3 or MgO is difficult to etch away.
Therefore, FBAR resonance-antiresonance method which is the most accurate method to obtainelectromechanical coupling coefficient kt in the GHz range cannot be used.
In this study, GHz kt value of SC-PZT films was extracted from HBAR (High-overtone bulk acoustic
resonator) structure including substrate. We fabricated the HBAR consisting of Pb(Zr0.53Ti0.47)O3 thinfilms near MPB with 2.8 m grown on (101)SRO/(001)Pt: total 100 nm /(001)MgO: 0.3 mm substrateby using RF magnetron sputtering. First, impulse response of HBAR is obtained by an inverse Fouriertransform of S11 measured by a network analyzer. As shown in Fig. 1 (a), acoustic waves excited fromPZT film propagate in MgO substrate, reflect at substrate bottom, and is detected again by PZT film.
Energy conversion efficiency so-called conversion loss (CL) including 1)electromechanical coupling of
the film, 2)mismatch between capacitive impedance of the film and 50  measurement system,3)transmission loss at boundary of each layer and substrate, 4)propagation and diffraction losses in thesubstrate (which is negligible in high k) can be obtained by Fourier transform of L1. 2) and 3) can be
simulated by Mason’s equivalent circuit model including each layer. Therefore, k value can be extracted
from the CL 236

236

Amplitude (dB)

(a)

(b)

0
-20
-40
-60
-80
-100

T. Yanagitani, et al., J. Appl. Phys., 102, 024110, (2007).

Longitudinal wave (L1)LS1
Shear wave

200
Au
PZT
Experiment (As grown)
Inactive PZT: dn
Experiment
SRO(After 130 kV/cm treatment)
Pt
Mason's model (dn= 300 nm, kt=0.395)
MgO
Mason's model (dn= 0 nm
kt=0.42)
Acoustic
30
wave

Conversion loss (dB)Figure 1 (b) shows the experimental andsimulated CL curves. 2nd-order thickness
extensional mode excitation observed at 1.2 GHz
in experi mental CL indicates the existence ofpiezoelectric inactive layer at initial stage of PZTgrowth. Simulated curve in which the inactive
layer is taken into account showed good
agreement in detail with the experimental curve.
kt value is determined to be 0.395. Next, 130
kV/cm was applied to the film to polarize theinactive layer. As a result, fundamental mode
was enhanced and 2nd order mode wassuppressed. In contrast to the previous result,simulated curve excluding the inactive layer
agreed well with the experimental curve. kt value
increased to 0.42 after the polarization treatment.
This method is an effective tool to investigate

0

40

80

120

160

Time (ns)

20
10
0
0.0

Suppression of 2nd order mode excitation
Enhancement of fundamental mode excitation

1.0

2.0

3.0

4.0

Frequency (GHz)

Fig. 1 (a) Impulse response of the PZT HBAR and(b) conversion loss obtained from Fourier transform of L1.
dn is the thickness of piezoelectric inactive PZT layer.

polarization state and kt value in the single
crystalline PZT films.

ISAF3-I1-4 ______________________________________________________________________________________________________________________

In-situ XRD observation of (100)/(001)-oriented Pb(Zr,Ti)O3
films under applied electric field
Hiroshi Funakubo1, Ayumi Wada1, Yoshitaka Ehara1, Shintaro Yasui1, Mitsumasa Nakajima1,
Takahiro Oikawa1, Hitoshi Morioka2, and Takeshi Kobayashi31Tokyo Institute of Technology, Yokohama, Japan
2
Bruker AXS K.K., Yokohama, Japan
3
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
Email: funakubo.h.aa@m.titech.ac.jp
Pb(Zr,Ti)O3 thick films prepared on Si substrates have been widely investigated for MEMS
applications. Piezoelectric response of the polydomain films consists of not only the lattice strain
but also other contributions, such as domain switching, phase transition and so on. To understandthese contributions individually, in-situ observation of the crystal structure under an applied electricfield is the most effective way. However, these investigation has been limited for Pb(Zr,Ti)O3 thickfilms1, 2. In the present study, we measured in-situ XRD analysis under an applied electric field aswell as before and after the applied electric field.

42

43

45

46

PZT 200

PZT 002PZT 200

442 (deg.)

Intensity (arbitrary units)

Osone et al., Appl. Phys. Lett., 90,
262905, 2005.
2
Morioka et al., Jpn. J. Appl. Phys.,
48, 09KA03, 2009.
3
Kobayashi et al., Thin Solid Films,
489, 74, 2005.

PZT 002

1

Intensity (arbitrary units)(100)/(001)-oriented Pb(Zr0.3Ti0.7)O3 and Pb(Zr0.52Ti0.48)O3 films with 1 m-thick wereprepared at 600 oC on (111)Pt/Ti/SiO2/(100)Si substrates by chemical solution deposition method3.
Capacitor structure of Pt/Pb(Zr,Ti)O3/Pt was used to measure the electrical properties. XRD
measurements were used to evaluate the crystal structure of the films on the Pt top electrodes using
concentrated X-ray source with the space resolution of about 50 m combined with two
dimensional detector (Bruker, D8).
Figure 1 shows the XRD patterns before, under, and after applied electric field of 150
kV/cm For Pb(Zr0.3Ti0.7)O3 films after 100 and 107 bipolar switching cycles Piezoelectric fatigue
was observed after 107 cycles as well as the polarization fatigue. However, the change in the XRD
patterns with the switching cycles was relatively small (see Fig. 1). On the other hand, the XRD
patterns change under applied electric field for the films after 100 cycles was smaller than that after
107 cycles. This shows that the domain switching from (100) to (001) was diminished after 107
switching cycles.
Crystal(a) 100 Cycle
structurechangeof(b) 107 Cycle
BeforeBeforePb(Zr0.52Ti0.48)O3 thick films is
Under 150kV/cm
Under 150kV/cm
After
After
also presented as well as thepiezoelectric property.

42

43

44

2 (deg.)45

Fig.1 XRD patterns before, under and after applied
electric fields of 150 kV/cm for Pb(Zr0.3Ti0.7)O3 films
after 100 and 107 bipolar switching cycles.

46

ISAF3-I1-5 ______________________________________________________________________________________________________________________

Piezoelectric responses of epitaxial PZT film-based
membrane in d31 and d33 actuation mode
Minh Nguyen1,2,3, Matthijn Dekkers1,2, Dave Blank1, Guus Rijnders1
1

Inorganic Materials Science (IMS), MESA+ Institute for Nanotechnology,
Universityof Twente, P.O. Box 217, 7500AE Enschede, The Netherlands
2
SolMateS B.V., Drienerlolaan 5, Building 6, 7522NB Enschede, The Netherlands
3International Training Institute for Materials Science (ITIMS), Hanoi University of Science andTechnology, No. 1 Dai Co Viet road, Hanoi, Vietnam
Email: d.m.nguyen@utwente.nl

The magnitude of the d33 coefficient is 2.0 to 2.5 times higher than the d31 coefficient. Therefore, thegenerated open-circuit voltage of a d33-mode device will be much higher (20 times or greater) than that of thed31-mode generator of similar dimensions, resulting in a potentially higher energy conversion factor. Hence,the d33-mode is the key to make the thin-film PZT device for power generation237.
In this report, d31 and d33 actuation mode micromechanical systems piezoelectric actuators and sensors
were fabricated and compared to investigate their displacements and quality factors. For d31-mode
membrane, an epitaxial Pb(Zr0.52Ti0.48)O3 (PZT) thin film was deposited on SrRuO3-buffered YSZ/Si
substrate; whereas, the deposition of the epitaxial PZT thin film was done on YSZ/Si substrate for d33mode membrane. All layers of PZT film (500 nm), SrRuO3 electrode (100 nm) and yttria-stabilized
zirconia (YSZ, 50 nm) buffered-layer were deposited using pulsed laser deposition (PLD). Diameter andthickness of the membranes were 300-1000 µm and 10 µm, respectively.

Fig. 67: Piezoelectric displacements of (a) d31-mode and (b) d33-mode membranes. The diameterof membranes is 500 µm. All measurements are performed at an ac-voltage of 3 V and 8 kHz
frequency.
The piezoelectric responses, including piezoelectric displacement and quality factor, were performed
using a laser Doppler vibrometer (LDV). The piezoelectric displacement and quality factor of the d31
and d33-mode were 22.4 nm/V and 102, and 10.2 nm/V and 128, respectively, with 500-µm in
membrane diameter. In this study, the center displacements of membranes were measured at an acvoltage of 3 V and 8 kHz frequency (off-resonance); while the quality factors were calculated fromresonance peaks which were measured at an ac-voltage of 1 V and in the frequency range from 0 to 2
237

Y. B. Jeon, R. Sood, J. -h. Jeong, S. -G. Kim, “MEMS power generator with transverse mode thin film PZT”, Sen. Actuators A, vol.
122, p. 16-22, 2005; W. J. Choi, Y. Jeon, J. H. Jeong, R. Sood, S. G. Kim, “Energy harvesting MEMS device based on thin film
piezoelectric cantilevers”, J. Electroceram., vol. 17, p. 543-548, 2006.

MHz. The effects of diameter membrane on the piezoelectric responses of the d31 and d33 mode havebeen also investigated.

Piezoelectric Energy Harvesting
CLUB B
Wednesday, July 24 2013, 04:30 pm - 06:00 pm
Chair:

Paula Vilarinho
Universoty of Aveiro

ISAF4-I2-1 ______________________________________________________________________________________________________________________

Energy Harvesting with Piezoelectric MEMSPaul Muralt, Andrea Mazzalai, Ramin Matloub
Ceramics Laboratory, EPFL, Lausanne, Switzerland
Email: paul.muralt@epfl.ch
During recent years, energy harvesting from vibration and motion sources has attracted muchinterest. Electrical power generators based on piezoelectric materials were investigated, first as
flexible piezoelectric bulk composite materials containing PZT ceramics, and later also as MEMS
devices based on thin films, or even nanowires. In case of micro power devices, the main target
applications are wireless communication, sensors, and specifically wireless sensors. Average supply
powers of 100 µW are sufficient to operate wireless nodes with low duty cycles. There is generalagreement on the fact that motions and vibrations constitute the most versatile and ubiquitousambient energy sources available, if light harvesting is excluded by the application. The progress inpiezoelectric thin films and MEMS technology has lead to the development of demonstration
devices that show sufficiently large power outputs and voltage levels, i.e. more than several 100µW/cm2 at over one volt. The standard configuration is to use parallel plate capacitor geometry
exploiting the transverse piezoelectric coefficient. It looks evident that Pb(ZrTi)O3 and related
ferroelectric materials should be the best choice. However, ferroelectric thin films exhibit highdielectric constants – meaning low voltage output - and usually suffer from limited remanentpolarization. Remedies can be found in using interdigitated electrode systems, or imprinted films.
Another solution, however, could be to use AlScN thin films. Substituting Al in part by Sc leads tohigher e31,f coefficients with only a moderate increase of the dielectric constant.
In this talk, the principles of piezoelectric energy harvesting will be introduced and illustrated withachieved results. Direct strain coupling to moving parts is compared to acceleration coupling bymeans of inertial masses. Specific thin films issues will be addressed such as material’s choice, andelectrode configurations. The interdigitated electrode system will be discussed in more detail,including growth on insulators, poling, domain issues and performance. The energy figure of merit
e*h as derived from measurements is introduced to compare materials and electrode systems.
Experimental results will be compared to numerical simulations.

ISAF4-I2-2 ______________________________________________________________________________________________________________________

Curled PZT Cantilever Based MEMS Harvester
Hyeonsu Park, Jongcheol Park, Jaeyeong Park*
Department of Electronic Engineering, Kwangwoon University, Seoul, Korea*Email: jaepark@kw.ac.kr
In this paper, a micro-fabricated PZT cantilever based energy harvester was newly developed togenerate high output voltages from two dimensional ambient vibrations. A curled PZT cantilever
was proposed to scavenge both vertical and longitudinal vibrations, which was comprised of apolyimide, PZT, and electrode layers formed on a low stress silicon nitride film. The inter-digitally
shaped electrodes were employed for the d33 piezoelectric mode operation and high output voltage.
The polyimide was utilized as an elastic layer to decrease the resonant frequency of the harvester.
The harvester generated an output voltage of 0.5 V and 1.08 V at its resonant frequency of 114.7 Hz
under a vertically and longitudinally induced vibration with an acceleration of 2.3 m/s2.
Most of MEMS vibration harvesters employing a flat cantilever can only be operated undervertically induced vibration1). Therefore, they must be installed on the perpendicular plane tovibration in order to achieve its maximum output power. However, the proposed device cangenerate electricity from both vertically and longitudinally induced vibrations. Since the arbitrary
vibration induced on the curled cantilever leads
the proof mass at the free end of cantilever tooscillate.
The proposed cantilever structure was realized byusing intrinsic bending deformation of a multilayered cantilever. The polyimide layer was
utilized as an elastic layer for lowering theresonant frequency of the cantilever due to its low
elastic modulus. The fabricated piezoelectric
cantilever has a volume of 4000×2000×18(height) μm3. The silicon proof mass has avolume of 2000×2000×500 (height) μm3. As
shown in Fig. 1, the fabricated curled PZT
cantilever has a radius curvature of 1.5 mm. The
fabricated PZT thin film has a remnant
polarization and coercive field of approximately
2Pr = 49.3 μC/cm2 and 2Ec = 67.6 kV/cm.

1)

(a)

(b)
(c)
Fig. 68: Photographs of top view (a), side view (b),and inter-digitally shaped electrodes of fabricatedcurled PZT cantilever based energy harvester with
d33-mode operation (c).

R. Elfrink, T. Kamel, M. Geodbloed, S. Matova, D. Hohlfeld, Y. Andel, R. Schaijk, Vibration Energy Harvesting with Aluminum
Nitride-based Piezoelectric Devices, J. Micromech. Microeng. Vol. 19, no.1, p. 251 ~ 265, 2009

ISAF4-I2-3 ______________________________________________________________________________________________________________________A Tunable Vibrating Piezoelectric Cantileverfor Energy Harvesting
Ahmed Seddik Bouhadjar, Despesse Ghislain, Defay Emmanuel1

CEA, LETI, Minatec Campus, Grenoble, France
Email: emmanuel.defay@cea.fr

This paper describes how an adjustable electrical load can be used to achieve a wideband
mechanical vibration energy harvester based on piezoelectric material. We discuss the design
optimization of the developed structure in terms of coupling mode and cantilever shape. The
developed device is based on the longitudinal piezoelectric mode of a cantilever in the centimeter
range. This last exhibits a resonance frequency at 208 Hz and 294 Hz respectively in short and open
circuit conditions. The key element of the tunability process is an adjustable electrical load, namely
a variable capacitor, coupled with the piezoelectric material which allows a controllable shift of theresonant frequency between these two frequencies. This device yields a frequency variation as highas 41%.
Fig. 1 sketches the cross section of the device
performed throughout this study. Piezoelectric
cuboids have been glued to a steel substrate.
PZN-5.5%PT single crystals have been chosen
thanks to their outstanding electromechanicalcoupling k332, namely 80%. Reaching such a highcoupling requires using the longitudinal
configuration, which induces a peculiar pattern of
PZN-PT subparts, as displayed in Fig.1. The
reversed polarization of adjacent subparts
prevents the compensation of the generated
charges. Note that the subparts are connected inparallel electrically in order to reach a highcapacitance and connected in series mechanicallyin order to reduce the mechanical stiffness.

Fig. 69: Sketch of the cross section of the tunable
harvester. Pre-poled piezoelectric cuboids in the mm
range have been arranged face to face and in parallelin order to avoid charge compensation. They areconnected to a variable load made of a capacitorsbank.

Fig.2 shows the measured resonance frequency ofthe cantilever once one makes vary the capacitive
load in parallel (see Fig. 1). Two orders ofmagnitudes of capacitance load induce afrequency variation as high as 41%. This device
is intended to harvest vibrating energy exhibitinga variable frequency.
Fig. 2: Frequency variation exhibited by the loaded
cantilever versus the capacitive shunt load.

ISAF4-I2-4 ______________________________________________________________________________________________________________________

Piezoelectric MEMS Vibrational Energy Harvester
Using BiFeO3 Films
T. Yoshimura1, S. Murakami2, K. Wakazono1, K. Kariya1, N. Fujimura1
1

Department of Physics and Electronics/Osaka Prefecture University, Sakai, Osaka/Japan
2
Technology Research Institute of Osaka Prefecture, Izumi, Osaka/Japan
Email: tyoshi@pe.osakafu-u.ac.jp

Recently, vibration energy harvester (VEH) is receiving a considerable amount of interest, because thevibration energy exists in many environments. Although several methods are useful for obtaining
electrical energy from vibration energy, piezoelectric materials are the most suitable because of theircapability of converting applied strain energy into useful electric energy directly and the ease withwhich they can be integrated into a system.
Various types of piezoelectric MEMS VEHs based on the mass-spring design have been reported.
Pb(Zr,Ti)O3 and AlN films are the most commonly used piezoelectric materials for VEHs. For VEH
applications, it can be expected that a piezoelectric film with a large piezoelectric coefficient and low
dielectric permittivity will exhibit a high figure of merits (FOM). We have proposed that BiFeO3 films
are suitable for piezoelectric VEH applications, because BiFeO3 has high spontaneous polarization andlow dielectric permittivity.1) We have also improved the piezoelectric properties of BiFeO3 films bydomain engineering and by using strain-induced morphotropic phase boundaries (MPB). The highest
FOM of a domain-engineered BiFeO3 film to date is 20.8 GPa, which is comparable to the bestperforming PZT films.

A VEH with a resonant frequency near 200 Hz was designed.
While the VEH was strongly affected by nonlinear resonance,
the VEH exhibited a relatively high output voltage of about 1
V·G-1 (G: 9.8m/s2). Fig. 1 shows the average output power ofthe VEH measured at the resonant frequency. The highest
power at an acceleration of 0.014 Grms is 3.3 W·mm-3·G-2.
This harvesting performance is comparable to piezoelectric
MEMS VEHs using other piezoelectric films.
Acknowledgement: This study was supported by Industrial
Technology Research Grant Program in 2011 from New
Energy and Industrial Technology Development Organization(NEDO) of Japan.
1) K. Ujimoto, T. Yoshimura, A. Ashida and N. Fujimura,Appl. Phys. Lett., 100 (2012) 102901.

Output Power (W·mm-3·G-2)

In this study, piezoelectric MEMS VEHs using BiFeO3 films were fabricated and its energy harvesting
performance was characterized. SOI wafers were used as substrates. The substrate was oxidized, andthen Pt/Ti bottom electrodes were deposited on the substrate by a sputtering method. BiFeO3 films were
deposited on the substrate by a sol-gel method. Microcantilevers were then fabricated by a conventional MEMS
10
process.

1
0.014G, 195.3Hz
0.084G, 196.0Hz

0.1

105

106

107

Load Resistance()Fig. 1 Average output power of theharvester using BiFeO3 films.

ISAF4-I2-5 ______________________________________________________________________________________________________________________

Efficient flexible nanogenerator made of organic ferroelectric
dabcoHReO4
Dmitry Isakov1, Etelvina de Matos Gomes1, Bernardo Almeida1, Igor Bdikin2 and Andrei Kholkin3.
1

University of Minho, Center of Physics, Campus de Gualtar, 4710-059 Braga, Portugal
University of Aveiro, Department of Mechanical Engineering and TEMA, 3810-193 Aveiro,
Portugal3
Department of Ceramics and Glass Engineering & Center for Research in Ceramic and Composite
Materias (CICECO), University of Aveiro, 3810-193 Aveiro, Portugal
2

Email: dmitry@fisica.uminho.pt
In the last years, one-dimensional nanostructures have gathered significant scientific, technologicaland industrial interest, for application in fields such as drug delivery and regenerative medicine,sensing and chemical catalysis, nanophotonics and nanoelectronics. In this regard special attention
has been paid to organic materials due to their low cost and structural flexibility. However, whileorganic 1D nanostructures can be produced by a variety of laboratory methods (polymerization
against porous templates, self-assembly, soft lithographies etc.), electrospinning is one of the few
technologies which can be adequately scaled-up to an industrial level. The electrospinning process
is based on the uniaxial elongation of a jet, ejected from the surface of a charged polymer solution
possessing sufficient molecular entanglements, in the presence of an intense electric field. The
plastic stretching of the electrified jet and concomitant solvent evaporation results in the formationof continuous nanofibers with significant cross-section reduction of up to six orders of magnitude.
The important feature of electrospun nanofibers is that the strong shear and electrostatic forces
experienced during the process cause the alignment of dopants, molecules and chains within theprincipal fiber axis. This is an especially attractive phenomenon for polar materials, since
promoting such internal molecular orientation (self-assembling) of the organic molecules can also
result in achieving polarized emission or enhanced polar properties and an anisotropic alignment ofactive components is expected to bring in new features and applications. Recent interest on
electrospun nanofibers for piezoelectric applications reveals a big potential of this low-cost
nanomanufacturing process for the development of fiber-based energy harvesting elements.
However, up to date, among the various organic polar materials, only nanofibers of PVDF havebeen used in piezoelectric actuators. In this work, we present a production of nanofibers of a room
temperature hybrid organic-inorganic ferroelectric 1,4-diazabicyclo[2.2.2]-octane perrhenate(dabcoHReO4).
The nanofibers have preferentially oriented dabcoHReO4 nanocrystals with their polarizedhydrogen bonds along the fiber axis displaying enhanced piezoelectricity and second harmonic
generation response. An efficient strain-electricity flexible nanogenerator based on parallel arraydabcoHReO4 nanofibers reveal above 100 mV output voltage and can be used as a sensitive
biocompatible strain sensor and implantable voltage generator.

Bulk Piezoelectric Materials
CLUB C
Wednesday, July 24 2013, 04:30 pm - 05:45 pm
Chair:

Pavel Mokry
Technical University of Liberec

ISAF4-I3-1 ______________________________________________________________________________________________________________________

Ian Reaney1
1
Materials Science and Engineering, Unversity of Sheffield, Sheffield, South Yorkshire, United Kingdom

From Materials Discovery to Prototype Devices
Ian M. Reaney
Functional Materials Group
Materials Science and Engineering
University of Sheffield, UK
The main goals of the Functional Materials Group (FMG) at Sheffield are to develop new materials,
characterise their structure and functional properties and develop prototype devices to demonstrate
their commercial potential. The remit of the FMG is broad with a wide range of projects that focus
on ionic conduction for Li-battery applications, magnetic memories and sensors, piezoelectrics,
MW and rf dielectrics and thermoelectrics. This presentation will review recent advances at
Sheffield in the development of i) Pb-niobate thins films for tunable filters, ii) high TC piezoelectric
ceramics and iii) dielectrically loaded MW antennas An overview of the key driving forces in thescience and technology of these topics will be presented followed by detailed descriptions of the
key advances made.

ISAF4-I3-2 ______________________________________________________________________________________________________________________

Phase Transition Toughening in Antiferroelectric Ceramics
Xiaoli Tan1, S. Eli Young1, Yohan Seo2, Kyle G. Webber,2 Jürgen Rödel2
1

Department of Materials Science and Engineering, Iowa State University, Ames, Iowa/USA
2
Institute of Materials Science, Technische Universität Darmstadt, Darmstadt/ Germany
Email: xtan@iastate.edu

In antiferroelectric solid crystals, the antiparallel electrical dipoles are originated from cation
displacements in the unit cell. Aligning these originally antiparallel electric dipoles to the directionof the applied electric field requires cooperative adjustment of the crystal lattice in many unit cells
and corresponds to a first order displacive phase transition. The vast majority of antiferroelectric
ceramics are based on the prototype compound PbZrO3 with the perovskite structure. In theseoxides, the antiferroelectric-to-ferroelectric phase transition manifests itself in the development of alarge polarization and is generally accompanied by a significant volume expansion when theapplied field exceeds a critical magnitude EF. The developed macroscopic polarization results fromthe antiparallel dipoles being forced parallel at the transition. The associated volume expansion at
the phase transition implies that there might be a toughening effect.
In this study, a series of Pb0.99Nb0.02[(Zr0.57Sn0.43)1-yTiy]0.98O3 (PNZST43/100y/2) solid solution
ceramics were investigated for their antiferroelectric  ferroelectric phase transitions. It was foundthat the induced ferroelectric phase is metastable in compositions with 0.07 ≤ y ≤ 0.08 at room
temperature. Strain measurements and X-ray diffraction analysis confirmed that the ferroelectricphase has a larger volume than the antiferroelectric phase. Crack growth resistance tests werecarried out at room temperature on compact tension specimens with dimensions of 24 mm  25 mm
 3 mm in PNZST43/6.1/2, 43/6.4/2, 43/6.7/2, 43/8/2, 43/10/2 ceramics. The results indicate thefracture toughness in PNZST43/8/2 is much higher than other compositions, verifying theantiferroelectric-to-ferroelectric phase transition toughening effect. The localized phase transitionzone was directly mapped with microRaman spectroscopy.

ISAF4-I3-3 ______________________________________________________________________________________________________________________High Power Piezoelectric Properties ofSome Bismuth Layer-Structured Ferroelectric Ceramics andtheir Applications to Ultrasonic Motors
Hajime Nagata1, Shun Endo1, Tadashi Takenaka1
1

Department of Electrical Engineering, Faculty of Science and Technology,
Tokyo University of Science/Japan
Email: h-nagata@rs.noda.tus.ac.jp

Recently, many high-power piezoelectric ceramic devices, such as ultrasonic motors andpiezoelectric transducers, have been developed so far. Hard Pb(Zr,Ti)O3 (PZT) ceramics with a highpiezoelectric strain constant dij and a high mechanical quality factor Qm are often used in highpower piezoelectric applications. Normally, hard PZT-based ceramics are driven at a vibration
velocity of 1 m/s owing to a resonance frequency change, heat generation and Qm reduction.
Additionally, PZT ceramics contain a large amount of PbO. Therefore, lead-free piezoelectricmaterials for replacing PZT have recently been demanded from the viewpoint of environmental
protection. The family of bismuth layer structured ferroelectrics (BLSFs) has been attracting
attention as a lead-free piezoelectric material for resonators and filters because they have large Qm
values. Thus, they seem to be good candidates for high-power ceramic devices realizing a largeamplitude and a linear stability against vibration velocity238,239. So, in this study, high-power
piezoelectric characteristics under continuous driving were studied on some bismuth layerstructured ferroelectric ceramics, i.e., Sr0.25Bi2.75Ti0.75Ta1.25O9 (SBTT, m=2), Bi4Ti2.98V0.02O12(BITV, m=3), Bi4Ti3O12-SrBi4Ti4O15 + MnCO3 0.2 wt% (BIT-SBTi, m=3, 4), and(Sr0.7Ca0.3)2Bi4Ti5O18 + MnCO3 0.2 wt% (SCBT, m=5).
The vibration velocities, v0-p, of SBTT, BIT-SBTi, and SCBT ceramics were above 2.0 m/s at 5
V/mm. Also, we observed that the resonance frequency changes and temperatures on the sample
surfaces for SBTT, BIT-SBTi, and SCBT ceramics were less than 1.0% and 50 ºC at a v0-p of 2.0
m/s, respectively. The high-power characteristics of the ceramics were superior to those of BITV
and hard PZT at a vibration velocity v0-p > 0.6 m/s. Therefore, SBTT, BIT-SBTi and SCBT
ceramics are promising candidates for lead-free high-power applications requiring high vibration
velocity and frequency stability.
As an example of the high-power piezoelectric application, we tried to demonstrate an ultrasonicmotor using some BLSF ceramics. The ultrasonic motor we fabricated by some BLSF ceramics
successfully rotated under the large amplitude driving around the resonance frequency. The
maximum rotation-speed was over 600 rpm on the ultrasonic motor fabricated by BIT-SBTi, and
SCBT ceramics. This rotation-speed was much higher than that in the motors by hard PZT
ceramics. Additionally, the resonance frequency of BLSF motor was almost constant under thelarge amplitude driving. In fact, the ultrasonic motor by SCBT ceramic was continuously rotated formore than 5 min without any control of the resonance frequency. This means that the ultrasonic238

S. Kawada, H. Ogawa, M. Kimura, K. Shiratsuyu, and H. Niimi: Jpn. J. Appl. Phys.,45 (2006) 7455.

239

H. Ogawa, S. Kawada, M. Kimura, K. Shiratsuyu, and Y. Sakabe: IEEE Trans. UFFC, 54 (2007) 2500.

motor using BLSF ceramics can eliminate the additional circuit for pursuing the resonancefrequency.

ISAF4-I3-4 ______________________________________________________________________________________________________________________

Using A New Design of Piezoelectric Device for Micro UEDM
Application
Yung Ting, Chia-An Wei, Chin-Chih Yeh, Chih-Hsuan Yu and Hsiang-Hung Huang
Department of Mechanical Engineering, Chung Yuan Christian University, 200, Chung Pei Rd. Chung Li, Taiwan
32023, ROC

Email: yung@cycu.edu.tw
Keywords： Micro UEDM, Piezoelectric Actuator, energy harvester
Abstract
Using two pieces of piezoelectric ceramics a two-stage energy harvester for an application of
micro Ultrasonic Electrical Discharge Machining (UEDM) is developed in this article. Ceramics inthe first stage (PZT#1) plays the role of actuator driven with oscillation of high frequency andamplitude. In the second stage (PZT#2), the ceramics receives part of the power transmitted fromthe actuator in the first stage and generates electricity of satisfactory voltage and current for theapplication requirement.
In the case study of micro UEDM, the entire system is designed and presented in Figure 1.
Fundamental components include an actuator, a generator, a compliant mechanism, and a proof
mass and so on. A selected example of electric power of about 0.4~3 watts for electrical discharge
and oscillation in the range of 150~500kHz for removing dregs is preserved in the second stage forthe application of micro UEDM. Design of the external power includes the oscillation frequency
and amplitude in the first ceramic actuator as well as the transmission mechanism to transfer theenergy from the first stage to the second stage. Modeling and analysis as well as experiment are
carried out. The analytical results are nearly approximate to the experiment results, and theoutcomes verify the proposed design can reach the target of generating both electricity andoscillation for the application of UEDM. Figure 2 is UEDM mechanism and Measurement data.
With power input to the first actuator to oscillate, the connected second one makes use of thetransmitted mechanical vibration energy to generate electricity, which has the meaning of
renewable energy. In case the energy expanse is less as compared to the general use for both
applications, the developed device has the advantage of energy saving. Moreover, this device builds
with both functions in one set that is compact and economic. Also, a micro structure is designed tocontrol electric power output with better function for micro UEDM.
FixturePZT#1

Proof mass
Insulation material
PZT#2

Spring
Axis
Electrode

PZT#1
Proof mass

Output262.43kHz

PZT#2Actuator

Generator

Compliant Mechanism

Fig. 1:Configuration of Micro UEDM using
Piezoelectric Ceramics

Output26.1 V

Fig. 2: UEDM mechanism and Measurement data

ISAF4-I3-5 ______________________________________________________________________________________________________________________

Efficient Compensation of Nonlinear Transfer
Characteristics for Piezoceramic Actuators
Felix Wolf1, Hartmut Hirsch1, Alexander Sutor1, Stefan J. Rupitsch1, Reinhard Lerch1
1Chair of Sensor Technology, Friedrich-Alexander-University, Erlangen, Germany
Email: felix.wolf@lse.e-technik.uni-erlangen.de

The hysteretic, nonlinear transfer characteristics is one of the main drawbacks when using
piezoceramic materials in actuator applications. Multiple effects on various length scales contributeto this difficult material behavior, making precise positioning and manipulation tasks erroneous.
Two solutions are commonly used to overcome these tracking errors:
1. The use of amplifiers with charge output
2. Open- and closed-loop control strategies
The second solution is more favorable, since thecharge-strain relation is only linear in a limited
operational range and circuitry of charge
amplifiers has some disadvantages. However,efficient models describing the nonlinear material
behavior are necessary for control strategies. The
Preisach hysteresis operator is such an efficientmodel, but it allows only for the calculation of
the transfer characteristics in forward direction,i.e.,Fig. 70: Desired target quantity ftarget, inverted
u(t) → fsim(t). An analytic inversion of this model input-signal uinv(ftarget) for discretization level M =for calculating the input uinv(t) required for a 200 as well as simulated model output fsim(uinv).
given output ftarget(t) does not exist.
In our previous work, we proposed a generalized Preisach model with an analytic weight function.
The model was extended to cover the influence of additional mechanical stress240 on the transfer
characteristics as well as of creep effects utilizing an additional creep operator241.
The scope of the present contribution is to introduce a novel algorithm allowing for an efficient
iterative inversion of the Preisach operator. The algorithm is based on a sophisticated two-stepsearch procedure in the Preisach plane representing the “memory” of the material. The computing
time depends on the discretization M of the Preisach plane. As our investigations reveal, adiscretization level of M=200 is sufficient for precise inversion and prediction results (see Fig.1).
For this discretization level, a maximum sampling frequency of 3.45 kHz is allowed for the signals
to be inverted.

240

F. Wolf, A. Sutor, S. J. Rupitsch and R. Lerch, A generalized Preisach approach for piezoceramic materials
incorporating uniaxial compressive stress, J. Sen. Act. A, 2012, 186, 223-229
241

F. Wolf, A. Sutor, S. J. Rupitsch and R. Lerch, Modeling and measurement of creep- and rate-dependent hysteresis
in ferroelectric actuators, J. Sen. Act. A, 2011, 172, 245-252

The model inversion is further verified via open-loop control of the strain output of soft PZT bulk
ceramics as well as of trimorph bending actuators. The model inversion we introduce shows to bean efficient tool for compensating the nonlinearities in piezoceramic actuator applications.

ISAF Group 3 Posters
Forum Hall
Wednesday, July 24 2013, 01:00 pm - 04:30 pm

ISAF-P3C-1 _____________________________________________________________________________________________________________________

Properties of Hafnium/Zirconium doped (Na1/2Bi1/2TiO3) Relaxor-Ferroelectric
Ceramics Under Bias Electrical Field
DERYA KIRSEVER1 and HUSEYIN YILMAZ2
1
2

Sakarya University, Department of Metallurgical and Materials Engineering, TURKEY
Gebze Institute of Technology, Department of Material Science and Engineering, TURKEY
dkirsever@sakarya.edu.tr, h.yilmaz@gyte.edu.tr

Abstract Lead-free piezoelectric materials are intensely studied due to being environmentallyfriendly. Among them, sodium bismuth titanate (Na1/2Bi1/2TiO3, or NBT) and its various solid
solutions have been drawing special attention as a new candidate for their lead based counterparts.
There is a great demand for reducing the adverse effect of lead. In this study, Hafnium or Zirconium
doped grain oriented (Na1/2Bi1/2)TiO3 (NBT) ceramics with <001> orientation were fabricated byTemplated Grain Growth (TGG) method using anisotropically shaped SrTiO3 template particles.
These molten salt synthesized SrTiO3 platelets were tape cast with calcined NBT powder, andsintered at 12000C for 6 h. Texture fractions up to 70% have been obtained. Hf 4 or Zr 4 doped
NBT ceramics were characterized by using X-Ray diffraction (XRD), scanning electron microscopy(SEM), polarization and electromechanical measurements. Electromechanical properties of Hf+4 andZr+4 doped NBT ceramics were studied under electrical bias. Unipolar strains up to > 0.25% was
measured. Electrostrictive coefficient of Hf+4 doped NBT ceramics were determined to be 0.032
m4/C2, which is much larger than that of PMN-based electrostrictive materials.

ISAF-P3C-2 _____________________________________________________________________________________________________________________

Simulation of the Locally Measured d33 ofPiezoelectric 1-3-Composites
Christoph Pientschke1, Sabine Kern1, Hartmut S. Leipner1
1

Martin-Luther-University, Interdisciplinary Center of Materials Science (CMAT),
06099 Halle (Saale), Germany
Email: christoph.pientschke@physik.uni-halle.dePiezoelectric 1-3-composites consist of aligned piezoelectric fibers or rods that are surrounded by apolymer matrix. The effective piezoelectric coefficient d33,eff of the composite can be calculatedwith analytic approximation formulas. The inputs of these formulas are the piezoelectric coefficient
d33 of the piezoelectric fibers or rods, their volume content and some mechanical properties of theconstituents. These formulas presume among others an uniform displacement of the composite
surface. However, the displacement of the surface is nonuniform. In addition to that thedisplacement is measured with a local method that is sensitive to a certain area of the surface. So
the questions arises: How does the measurement process influence the measured mean d33 of thecomposites and to what amount does it deviate from the prediction of the approximation formulas?
To answer these questions, the experimental situation was simulated using the finite-elementmethod (FEM) and a subsequent analysis.
In the simulated experiment, the d33 is quasi-statically measured. For this purpose, the local
displacement is translated to a capacitive distance detector using a tappet touching the sample
surface within a measuring spot. The tappet is moved by the largest displacement within that spot.
The d33,eff of the 1-3-composites is determined by averaging the local measured piezoelectriccoefficients of several tappet positions. For the simulations, the local displacements of 1-3composites were calculated with FEM. 1-3-composites with periodically and randomly arranged
piezoelectric rods were investigated. The resulting data were displayed as a contour plot with pixel
values related to the local displacement. The measuring spot was represented by a circle. It was
randomly placed on the contour plot. The largest pixel value within that circle was regarded as
representation of the measured local d33. This procedures were repeated several hundred times. The
resulting values were statistically analyzed.
According to the simulations, the measured mean d33 and the effective d33,eff calculated by theapproximation formulas differ significantly. This deviation is not only affected by the measuring
spot diameter but also by the volume content of the piezoelectric rods and the thickness of thecomposite. The approximation formulas overestimate the actual mean d33 of the composites. The
difference of the calculated d33,eff and the measured mean d33 is smaller than this because increasing
spot diameters result in an increase in the measured mean d33. In addition to that the distribution of
the measured d33 changes significantly with increasing spot diameters. For small spot diameters, thedistribution of the measured mean d33 and the actual value of the whole surface are similar. The
inner structure of the 1-3-composites influences the distribution of the measured d33. The standard
deviation of the measured d33 is a function of the spot diameter. It decreases with increasing spot
diameters. For small volume contents, it reaches a maximum before decreasing.
Summarizing, the simulations provide a new access to the understanding of the distribution of
locally measured d33 of piezoelectric 1-3-composites and to its relation to approximation formulas.

ISAF-P3C-3 _____________________________________________________________________________________________________________________

Structure and Ferroelectric Properties of Multiferroic
BiFeO3/SrTiO3 Superlattices Prepared by RF Sputtering
Hsin-Yi Lee1, Shang-Jui Chiu1, Ge-Ping Yu2
1

2

National Synchrotron Radiation Research Center, Hsinchu, Taiwan
Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu, Taiwan
Email: hylee@nsrrc.org.tw

Intensity (arb. units)

Asymmetric superlattice structures consisting of multiferroic BiFeO3 (BFO) and paraelectric SrTiO3(STO) sublayers were grown on a Nb-doped STO substrate with rf magnetron sputtering at
30
temperatures in a range 500 - 800 oC. For a
STO substrate (002)
10
(a)
27
substrate temperature less than 500 and at 800 oC
10
24
only poorly crystalline films resulted, whereas a
1021
10
BFO/STO superlattice structure film of great
18
750 C
10
*
crystalline quality was obtained for a substrate
*
*
15
*
o
*
*
10
temperature in a range 550 - 750 C. To
*
*
700 C
12
10
characterize the structure of the buried interface
9
10
650 C
and the surface morphology of these films, we
6
10
measure the x-ray reflectivity and diffraction
3
600 C
10
pattern. The fitted result from x-ray reflectivity
0
10
550 C
-3
curves shows that the density of the BFO film is10
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5
slightly less than that of the bulk phase. The
L (r. l. u)formation of a superlattice structure was100
confirmed through both the appearance of Bragg
80 (b)
lines separated by Kiessig fringes in x-ray
60
reflectivity curves and the satellite features of a40(002) diffraction pattern. The clearly discernible
20
main feature and satellite features on both sides of0
the substrate around the (002) STO Bragg peak of
-20
550 C
superlattice films indicate the high quality of the
600 C
-40
650 C
BFO/STO artificial superlattice structure as shown
-60
700 C
in Fig. 1(a). For BFO/STO superlattice films
-80
750 C
o
BFO single layer
deposited at 600-750 C, an increased crystalline-100-1500 -1000 -5000500 1000 1500
quality with smaller interface roughness correlatesElectric field (KV/cm)
with larger lattice strain and remanent polarization
Fig.
71:
(a)
Intensity
distribution of a (002) radialof the film. The measurement of hysteresis loops
scanof
BFO/STO
superlatticefilms deposited atshows that the largest remanent polarization (Pr)varied substrate temperatures. An arrow marks theooccurs at deposition temperature 600 C as shown
position of the superlattice main peak and a dashedin Fig. 1 (b). These measurements of the line denotes the position of the mean value of thehysteresis loops show that the ferroelectric superlattice. (b) Electric hysteresis loops ofproperties of BFO/STO superlattice films are superlattice films deposited at varied substrate
highly correlated with lattice strain, interface temperatures. For a single-layer film of BFO
roughness and crystalline quality of the films.
(thickness 40 nm) deposited at 600 oC and prepared
SL(0)SL(-1)

SL(-4)

SL(-3)

SL(-2)

o

SL(1)

SL(2)

SL3)

SL(4)

o

o

o

2

Polarization (C/cm )

o

o

o
o
o
o

under the same sputtering conditions, 2 Pr ~ 40 C
cm-2.

1

S. J. Chiu, Y. T. Liu, H. Y. Lee, G. P. Yu and J. H. Huang, J. Crystal Growth 334, 90-95 (2011).

ISAF-P3C-4 _____________________________________________________________________________________________________________________

Inverse Scheme to Identify the Temperature Dependence ofElectromechanical Coupling Factors for Piezoceramics
Stefan J. Rupitsch, Jürgen Ilg, Reinhard Lerch
Chair of Sensor Technology, Friedrich-Alexander-University Erlangen-Nuremberg
Email: stefan.rupitsch@lse.eei.uni-erlangen.deFinite element (FE) simulations are oftentimes utilized to predict the electrical as well asmechanical behavior of devices incorporating piezoceramic materials. Apart from the setup of thedevices, precise material parameters of the piezoceramics are indispensable to obtain reliable
simulation results. These material parameters determine theelectromechanical coupling factors which are decisive
quantities for applications of piezoceramic materials. As
devices usually operate in a certain temperature range, thetemperature-dependent behavior of the material parameters
has also to be considered within FE simulations.
Common approaches to identify material parameters of
piezoceramic materials are based on the IEEE/ANSI
standard1. Thereby, the frequency resolved electrical
impedance of several samples exhibiting different geometries
is acquired and analyzed. By means of simple analytical
relations, 10 independent material parameters can becomputed which entirely characterize the piezoceramicmaterial. However, the IEEE/ANSI standard presumes
monomodal mechanical vibrations of the investigated samples
that cannot be fulfilled in practice. As a result, the determinedmaterial parameters do not yield reliable simulations forpiezoceramics. On account of this fact, we developed analternative approach for the identification of accurate material
parameters2. The approach is based on an adjustment of FE Figure 1: (a) Variation of selected
simulations to measurements. In particular, the electrical material parameters with respect tobehavior of two block-shaped piezoceramic samples featuring temperature for PIC255. (b) Resulting
different directions of polarization is investigated. With the electromechanical coupling factors.
aid of an Inverse Scheme, the material parameters serving as input quantity of the FE simulation are
adjusted in a convenient way. Since this approach utilizes FE simulations, the identification
procedure is not based on the assumption of monomodal mechanical vibrations.
In order to study the variation of material parameters as well as coupling factors with respect to theambient temperature, the piezoceramic samples were placed in a climatic chamber providing thetemperature range -35 °C to 145 °C. Figure 1a shows temperature-dependent variations of selectedmaterial parameters for the piezoceramic material PIC255 which were identified by means of the
Inverse Scheme. As can be seen, the dielectric coefficientstrongly relies on temperature. In
contrast, the elastic stiffness modulus
remains nearly constant. Although the dielectriccoefficients are altered up to 50%, the electromechanical coupling factors decrease only slightly
with increasing temperature (see Fig. 1b). Hence, we can state that the performance of thepiezoceramic material PIC255 stays almost constant in the investigated temperature range.
1
2IEEE Standard on Piezoelectricity, ANSI-IEEE Std 176-1987.
S.J. Rupitsch, R. Lerch, Applied Physics A, vol. 97(4), p. 735-740, 2009.

ISAF-P3C-5 _____________________________________________________________________________________________________________________

Short pulse characterization of nanosecond-range dielectricdegradation in ferroelectric thin-film capacitors
A.Q. Jiang, T.A. Tang
State Key Laboratory of ASIC & System, Department of Microelectronics, Fudan University,
Shanghai 200433, People’s Republic of China
Email: aqjiang@fudan.edu.cn
Generally, the ferroelectric capacitance under a dc voltage stressing drops continuously withtime over a few days and months, and the capacitance-voltage (C-V) loop looks like a butterfly
shape. The slow dielectric degradation is considered to originate from oxygen-vacancy motion
and/or defect-dipole alignments along the field242. The large nonlinear capacitance can be applied
to high-density dynamic random access memories, tunable microwave filters, and phased array
antennas2. If the C-V sweeping time is short enough, the mechanisms beyond the defect-related
slow processes should be protruded. With modern techniques, domain switching speed can becharacterized from a series of voltage pulses with widths as short as a few nanoseconds.14 It is
curious what happens in C-V loops as the voltage sweeping time is shortened into the nanosecond
order. Obviously, the present commercial electrical bridges cannot realize so high a voltage
sweeping speed.
50

50 ms

C (pF)

With the improved short-pulse measurements, we
1.08 s45
estimated the differential capacitance of ferroelectric
Au/BiFeO3/LaNiO3/SrTiO3
and40
Pt/IrO2/(Pb(Zr,Ti)O3/IrO2/Pt thin-film capacitors from35
nanosecond discharging currents induced by a delta
30
voltage overlapping each stressing voltage pulse withwidths of 500 ns – 1 s. With the shortening of this25
pulse width, we clearly observed two capacitance
-12
-8
-4
0
4
8
12
maxima from each branch of capacitance-voltage
V (V)loops (C-V) in Fig. 1, reminiscent of an Fig. 72: C-V loops for 300 nm thick BiFeO3
antiferroelectric behavior. This finding provides the thin films under different voltage sweeping
evidence of the nonlinear dielectric contribution of times with electrode area of 7.8510-5cm2.
reversible domain motion. The reversible domains canalign along the field under the voltage, but reverses back immediately into their previous directions
under a reduced field strength to release their polarization charge, just like an antiferroelectric. As
the voltage stressing time is long enough, the internal field to drive the reversible domain motion is
temporally screened by the near-electrode charge injection. Finally, we evidenced the charge
injection from the imprint profile and reversible domain freezing into irreversible domains uponcooling.

1.

2.

Y.A. Boikov, B.M. Goltsman, V.K. Yarmarkin and V.V. Lemanov, “Slow capacitance relaxation in(BaSr)TiO3 thin films due to the oxygen vacancy redistribution”, Appl. Phys. Lett., vol. 78, p. 3866-3868,
2001.
F. DeFlaviis, N.G. Alexopoulos and O.M. Stafsudd, “Planar microwave integrated phase-shifter design withhigh purity ferroelectric material”, IEEE Trans. Microwave Theory Tech. vol. 45, p. 963-969, 1997.

ISAF-P3C-6 _____________________________________________________________________________________________________________________

Characteristics and structure of Mn-doped (0.6-x)PMT-0.4PT-xPZ
ternary system near morphotropic phase boundary
Hua Hao,Hanxing Liu,Wenhua Sun,Zhonghua Yao,Minghe Cao,Zhiyong Yu
School of Material Science and Engineering; State Key Laboratory of Advanced Technology for
Materials Synthesis and Processing,Wuhan University of Technology, Wuhan，P.R.China 430070
Email: haohua@whut.edu.cn
The excellent electrical properties and potential applications of Pb(B’1/3B’’2/3)O3 lead-based
perovskite relaxor ferroelectrics have attracted considerable research interest. Comparing to thelarge number of papers on the niobate perovskite relaxors and their solid solution, very few
investigations on the Pb(Mg1/3Ta2/3)O3(PMT) and related solid solution were reported till now. As
observed in other systems such as Pb(Mg1/3Nb2/3)O3- PbZrO3(PZ)-PbTiO3(PT), anomalously gooddielectrical properties were observed for compositions lying near the morphotropic phase boundary(MPB). Therefore, improved dielectric properties with increasing transition temperature can be
expected in PMT-PZ-PT system, due to the relatively high Curie temperature of end members of PZ(TC =230oC) and PT (TC = 492oC).
In this work, the tetragonal intensity ratio TP(%) of (0.6-x)PMT-0.4PT-xPZ(x=0.2) samples doped withvarious MnO2 values(0~1.0%(wt)) was calculated by Raman spectra. TP(%) values increase with MnO2
doping content from 67.6% to 78.3%, then decrease sharply at the doping limit. XRD testing of Mn 0.2%(wt) doped (0.6-x) PMT-0.4PT-xPZ(x=0.25) sample indicates more tetragonal phase at room temperatureand XRD peak tested at 90-160oC become broader, induced by the rhombohedral to tetragonal phasetransition. The remnant polarization (Pr) was found to be increased while the coercive field was decreased
with increasing Mn doped level. Due to the hardening effect caused by the Mn addition, the dielectric
constant and loss of 0.35PMT-0.25PZ-0.4PT ceramics decreased, while the mechanical quality factors were
found to increase up to 790. Meanwhile, the piezoelectric coefficient (d33 ~435pC/N) and electromechanicalcoupling factors (kp = 59%) were found to increase showing a “soft” effect.

Table 1 Dielectric and piezoelectric properties of Mn-doped 0.35PMT-0.25PZ-0.4PT
Samples

εr

loss

d33
（pC/N
）

kp
(%)

Qm

Tc
(oC
)

Pr
(μC/cm2)Ec(kV/cm)0.35PMT-0.25PZ0.4PT

2000

0.035

215

26

110

185

17.3

8.7

MnO2 0.2%(wt)

1530

0.005

435

59

790

197

29.9

6.2

MnO2 0.5%(wt)

1085

0.005

300

42

605

194

23.9

8.1

ISAF-P3C-8 _____________________________________________________________________________________________________________________

Domain Size Effects on the Local d33 of Tetragonal(Na0.53K0.45Li0.02)(Nb0.8Ta0.2)O3 Ceramics
Jeong-Ho Cho, Duc-Thang Le, Young-Hun Jeong, Joong Hee Nam, Ji-Sun Yun, Jong-Hoo Paik,
and Byung-Ik Kim
Intelligent Electronic Component Team, Korea Institute of Ceramic Engineering and Technology,
Seoul 153-023, South Korea
Email: goedc@kicet.re.kr
Lead-free (Na0.53K0.45Li0.02)(Nb0.8Ta0.2)O3 (NKLNT) was prepared using a conventional coldpressing method. A commercial Piezoresponse Force Microscope (PFM) was applied to observe thedomain structures of NKLNT ceramics. The typical configuration of the ferroelectric domain was
analyzed in abnormal grains with grain sizes that exceeded 40 µm, where tetragonal 90o domains
are predominant.
In this study, ferroelectric domains and the local piezoresponse were investigated in tetragonal Li–
and Ta–modified NKN (NKLNT) ceramicmaterials. PFM observations revealed a typicaltetragonal domain structure with 90o lamelladomains predominating. Measurements of thelocal piezoresponse indicated that the equilibrium
domain size greatly influences the coercive field
and local longitudinal piezoelectric coefficient.
The coercive field (Vc) decreased and themeasured value of longitudinal piezoelectriccoefficient (d33) increased significantly with adecrease in the domain size (dw). These changes
confirm that the domain size should be considered
as a very important parameter which contributes
to the piezoelectric properties of ceramics.
Finally, the most interesting aspect here is thepossibility that the piezoelectric performance ofthe lead-free NKLNT ceramics can be improved
due to the investigation of the optimum domain Fig. 73: Transmission electron microscopy (TEM)
size. Therefore, the introduction of microware image of NKLNT ceramics shows lamella anddomains
existing
sintering to NKLNT ceramics may be proposed in herringbone-shaped
simultaneously.
The
domainsize
isevaluated<1 lm.
this case.

ISAF-P3C-9 _____________________________________________________________________________________________________________________

Resistive Hysteresis of MOD-made BaTiO3 Ferroelectric Thin
Film Dependent on Film Thickness
Syu Ou, Hideaki Kawahara, Kaoru Yamashita, Minoru Noda
Grad. Sch. Sci. & Tech., Kyoto Institute of Technology, Kyoto, Kyoto/Japan
Email: noda@kit.ac.jp

Current density (A/cm2)

Current density (A/cm2)

A perovskite BaTiO3 (BT) thin film has been so far much investigated as a successful ferroelectricmaterial. Moreover, a recent epitaxially grown BT ultrathin film as thin as 1-3 nm realized definite
ferroelectricity (as piezoelectricity) [1]. While, BT family of perovskite ferroelectric film has
generally showed considerable ‘size effect’ that means either ferroelectricity or high permittivity islost when the film becomes thinner than a critical thickness. On the other hand, as one of apromising candidate material for Resistive RAM (ReRAM), the BT film has been also investigatedfor its resistive hysteresis and mechanism [2,3]. For the latter researches, however, the focus ismainly on properties of charge transfer mechanism in the oxide film as a conventional paraelectric
metal oxide but not much on those of intrinsic ferroelectric behavior in the BT film. In this work,
we formed MOD(Metal-Organic-Decomposition)-made BT thin film with chemical stoichiometry
then investigate the relation between the film thickness dependence of its ferroelectricity and theresistive hysteresis.
10-2
An MOD solution of BT was spin-coated on a sputtered
10-3
Pt(111)/Ti/SiO2/Si substrate with condition of 500 rpm-3
2
3
10-4
o
s/3000 rpm-30 s, thereafter dried on a hot plate at 200 C for
10-5
10 min. These processes were repeated once or twice to the
10-6
thickness of about 60 or 110 nm, and RTA final-annealed at
10-74600 oC for 20 min in ambient atmosphere. XRD(2-) revealed
10-8
1that the prepared film was polycrystalline and (110) and (101)
10-9
10-10
preferentially oriented. A BT film by two MOD layers with
-4000 -2000
0
2000
4000
around 110 nm-thickness revealed remanent polarization (Pr)Electric Field (kV/cm)
2
of about 5 C/cm and coercive force (Ec) of about 1-2 MV/cm
at room temperature. Figure 1 shows absolute value of current Fig. 74: Resistive hysteresis of 110
density vs. electric field, meaning resistive hysteresis of the nm-thickness BaTiO3 2-MOD layer
110 nm-BT film when applying 3rd triangle electric field scan film.
(0--> Max.(+4500kV/cm)-->0-->Min.(-4500kV/cm)-->0). It isclear from Fig. 1 that the leakage level keeps different
throughout the electric field and the ratio is around 1-2 order of
2
10-3
3
magnitude between scans of + and – direction of electricfield(blue and red, respectively), whereas the leakage curve is
10-4
dependent on polarization reversal at near Ec. Next, we made1
4
one MOD layered BT film with around 60 nm thickness,-510
which showed little Pr and Ec, respectively, meaning its
ferroelectricity is almost lost. A resistive hysteresis of the 60
10-6
nm-BT film(Fig. 2) when applying the same scans above-4000 -2000
02000 4000
shows no relation with the polarization reversal but some ‘set’
Electric Field (kV/cm)
and ‘reset’ events of current are observed similar to [2,3] athigher electric field (2.5 to 3.0 MV/cm) than Ec, which ismaybe unipolar switching [2]. Current on/off ratio between the Fig. 2: Resistive hysteresis of 60 nmthickness BaTiO3 1-MOD layer film.
‘set’ and ‘reset’ seems small to be about 3.

Therefore, it is thought from the results that the current on/off ratio is much larger for 110 nm-BT
than for 60 nm-BT. This indicates a possibility that the existence of ferroelectricity relates to theon/off ratio in the resistive hysteresis phenomena of BT thin film.

ISAF-P3C-10 ____________________________________________________________________________________________________________________

Effect of polarization switching on the electron emission of PZST
antiferroelectric ceramic
Yang Liu,1,2 Yujun Feng,1 Hongliang He,2 and Zhuo Xu1
1

Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education &International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China
2

National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics,
CAEP, Mianyang 621900, People’s Republic of China
Email: sakulaly@gmail.com

Abstract
Stable pulse electric-field-induced electron emissions from antiferroelectric cathode material leadzirconate stannate titanate (PZST) have been investigated. According to the same composition, we
analyzed the results of three different pulse-loading types. For antiferroelectric, the polarization
change could be written as P   A  PS , where  A and PS defined, respectively, the polarization
switching factor and the saturated polarization. For ferroelectric (the orientation of polarization was
codirectional with the positive pulse), the polarization change P   B  ( PS -Pr ) , where Pr referredremnant polarization. For ferroelectric (the orientation of polarization was reverse with the same
pulse), the polarization change P  C  ( PS  Pr ) . It was found that the emission charges which were
gotten from the emission current waveforms were increasing with the polarization switching factor

 i decreasing. The results may give an insight into the physical mechanism underlying the emission
process.

ISAF-P3C-11 ____________________________________________________________________________________________________________________

Evaluation of the Polarization State of Piezofiber Composites
Agnes Eydam1, Gunnar Suchaneck1, Kai Hohlfeld2, Sylvia Gebhardt3, Alexander Michaelis2,3,Gerald Gerlach1
1

TU Dresden, Solid State Electronics Lab, Dresden, Germany
TU Dresden, Institute of Materials Science, Dresden, Germany
3
Fraunhofer Institute for Ceramic Technologies and Systems, Dresden, Germany
2

Email: Agnes.Eydam@tu-dresden.deIntegrated piezoelectric sensors and actuators find applications for health-monitoring, for reducing noise
emission, for vibration control and damping, etc. The polarization distribution of piezoelectric materials
is usually determined by means of thermal waves recording the time or frequency dependencies of the
pyroelectric current. In the so-called Laser Intensity Modulation Method (LIMM) an intensitymodulated laser beam is absorbed in the sample and generates thermal waves with a modulationfrequency-dependent penetration depth. The average pyroelectric coefficient pav can be additionallymeasured by heating the whole sample harmonically at low modulation frequencies by means of a
Peltier element and determining the pyroelectric current.
In this work, we evaluate the polarization state of PZT
fibers embedded in epoxy resin. The investigatedsamples could be described as 1-3 piezocomposites.
Irregularly arranged PZT fibers with about 330 µm in
diameter represent the active phase which iscontinuous in only one direction.
An analytical solution of the 1-D thermal problem wasderived for an embedded piezoelectric plate. The
homogeneously poled, harmonically heated plate
exhibits heat losses to the environment characterized
by a continuous distribution of relaxation times . This Fig. 75: Pyroelectric current spectrum of amodel was then applied to fiber composites as fiber composite sensor in comparison with aillustrated in Fig. 1. The average pyroelectric fit to an analytical model. The real part ofcoefficient of the PZT fibers is in the range of 10-11 to the pyroelectric current is denoted as Re and10-10 C/cm²K. We have evaluated the influence of fiber the imaginary part as Im.
processing parameters on the polarization state bycomparing the values of pav and also the amplitudes of the pyroelectric current. The value of the
spontaneous polarization Ps was derived from the P-E hysteresis loop.
The penetration depth of the thermal wave is determined by the thermal diffusivity of the material andthe circular frequency of heat modulation. The thermal diffusivity of the piezofiber composite wasestimated (i) by the laser flash method and (ii) by means of the frequency dependence of the pyroelectriccoefficient determined under conditions of sufficient heat losses to the environment from the top
electrode. Here, the threshold frequency of thermal wave confinement in the piezoceramic layer was
evaluated.
We demonstrated that the thermal wave method is a promising non-destructive tool to evaluate thepolarization state of piezofiber composites. By this way, the influence of thermal and mechanical loads
during the fabrication process can be evaluated.

ISAF-P3C-12 ____________________________________________________________________________________________________________________MPB in x(BaZrO3)-y(Bi(Mg0.5Ti0.5)O3)-z(K0.45Na0.5Li0.05)NbO3 leadfree piezoelectric ceramics
Ruilin Wu1, Guorong Li1, JiangtaoZeng1, Liaoying Zheng1
1

Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, China
Email: zhengly@mail.sic.ac.cn

During the last years, with the increase of awareness for environmental topics243., lead-freepiezoelectric draw much attention. The lead-free alkali niobate ceramics based on (K, Na)NbO3(KNN) are the most promising one because of its high Tc and good piezoelectric properties244. From
low temperature to high temperature, KNN undergoes successive phase transitions which can be
adjusted by adding some dopants to improve its temperature stability245..
The x(BaZrO3)-y(Bi(Mg0.5Ti0.5)O3)-z((K0.45Na0.5Li0.05)NbO3) lead-free piezoelectric ceramics has
been prepared by solid-state reaction
method. The dielectric properties,
ferroelectric properties and piezoelectric
properties have been investigated. The Zr+
occupied the B site of KNN lattice whichcaused the structure transforming fromorthorhombic to tetragonal, while the Ba2+
occupied the A site caused transformingfrom orthorhombic to rhombohedral. A
morphotropic phase boundary (MPB)
between a rhombohedral phase and atetragonal phase was found.
Fig.76: XRD patterns of the BZ-BMT-KNLN
The addition of BMT made the ceramics
ceramics at room temperature.(a)BZ-BMTrelaxation. The BZ-BMT-KNLN ceramics
KNLN8/1/91(b) BZ-BMT-KNLN7/1/92
is a potential lead-free piezoelectric
ceramics.

243

Alain Brice Kounga, “Morphotropic phase boundary in (1-x)Bi0.5Na0.5TiO3-xK0.5Na0.5NbO3
lead-freepiezoceramics”, Appl. Phys. Lett., 92, 222902, 2008.
244
Pei Zhao, “High piezoelectric d33 coefficient in Li-modified lead-free (Na,K)NbO3 ceramics
sintered at optimal temperature”, Appl. Phys. Lett., 90, 242909, 2007.
245
Laijun Liu, “Oxygen-vacancy-related high-temperature dielectric relaxation and electricalconduction in 0.9K0.5Na0.5NbO3-0.05BaZrO3 ceramics”, Physica B, 407, 136-139, 2012.

ISAF-P3C-13 ____________________________________________________________________________________________________________________

Photo-optical Properties of Functional Chiral Photochromic
Liquid Crystalline Polyacrylates
Natalia Podoliak1, Alexey Bobrovsky2, Alexej Bubnov1, Vĕra Hamplová1, Miroslav Kašpar1,
Valery Shibaev2
1

Institute of Physics, Academy of Sciences of the Czech Rep., 182 21 Prague, Czech Republic
2
Faculty of Chemistry, Moscow State University, Leninskie gory, 119992 Moscow, Russia
Email: podoliak@fzu.cz

Due to photosensitivity, low molar mass liquid crystalline (LC) materials and LC polymer systems
containing azobenzene groups are very promising materials for optical data recording andoptoelectronics. Recently, several series of photosensitive materials have been synthesized246 and therespective liquid crystalline polyacrylates (LCP) have been prepared and studied.
Comparative study of chiro- and photo-optical properties of three new chiral photochromic azobenzenecontaining comb-shaped LCP has been performed. These LCP contain the same polyacrylate backbones,
but have different structure of azobenzene-containing mesogenic groups with chiral chain. Dependingon the chemical structure, they exhibit cholesteric N*,
paraelectric SmA* and ferroelectric SmC* phases.
Lateral chlorine substituent in the mesogen fragment
0,8
beforeafter
leads to an extreme decrease of isotropisation
0,6
temperature and causes a disappearance of N* phase.
0,4
Circular dichroism (CD) spectra demonstrate a formation
0,2of helical order elements even in the amorphousised spin0,0
coated polymer films. Possibility of manipulation of CD
0,2values and degree of a helical order by light and0,4annealing was studied. UV-irradiation of all polymers
0,6
induces E-Z isomerization of azobenzene groups,
0,8
disrupting LC-order. On the other hand, the irradiation of
LCP films by polarized light leads to a photoorientation Fig. 77: Polar diagram of polarized absorbanceprocess due to the cycles of E-Z-E isomerization (see Fig. before and after (220 s) the polarized light1). As a result, an appearance of significant linear irradiation (457 nm, ~0.5 W/cm2) of LC polymer
dichroism, dependent on the relative position of amorphousised film.
azobenzene moiety, was observed. The observed photooptical phenomena are of considerable interest for possible application of chiral photo-chromicpolyacrylates in photonics and optoelectronics. For example, the synthesized LCP could be used as
photoactive media for optical data storage with the possibility of non-destructive data reading. Optical
recording could be realized by the photo-induced local change of birefringence or optical activity
modulation. In both the cases the reading of recorded information could be performed by light with thewavelength outside the azobenzene chromophores absorbance band, ensuring the absence of erasing
during the reading.
90

Absorbance at 326 nm

120

60

30

150

180

0

330

210

240

300

270

246

M. Kašpar, et. al., Liq. Cryst. 2004, 31, 821; A. Bubnov, et. al., Mol. Cryst. Liq. Cryst. 2007, 465, 93; M. Kašpar, et. al., Eur. Pol.
J. 2008, 44, 233; V. Novotná, et. al., J. Mater. Chem. 2009, 19, 3992; A. Bobrovsky, et. al., Liq. Cryst. 2009, 36, 989; A. Bubnov, et.
al., Phase Transitions 2010, 83, 16.

This work is supported by projects: ASCR M100101204 & M100101211, CSF P204/11/0723 &CSF 13-14133S.

ISAF-P3C-14 ____________________________________________________________________________________________________________________

High-frequency dielectric properties of Pb(Fe1/2Nb1/2)O3
ceramics and single crystal
R. Mackevičiūtė1, J. Banys1, A. Kania2, V. Goian3, D. Nuzhnyy,3 S. Kamba3
1

Vilnius University, Faculty of Physics, Vilnius, Lithuania
A. Chelkowski Institute of Physics, University of Silesia, Katowice, Poland
3
Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
2

Email: Ruta.Mackeviciute@ff.vu.lt

''

'

Multiferroic materials, like bismuth ferrite (BFO), lead iron niobate (PFN) and others draw a lot ofscientific attention in recent years, as the possibility to control magnetization with electric field, or
polarization with magnetic field. It opens the route to a wide variety of new applications. However,despite the fact that PFN ceramic was studied more than 50 years247, a dispersion of dielectric
permittivity is still not investigated in a wide frequency range.
Dielectric measurements were performed between 300 and 500 K in the frequency range from 20
Hz to 0.8 THz. PFN ceramics are known toundergo a single diffuse phase transition between
1 MHz
370 K and 380 K1. This is characterized by a
3 MHz
broad peak in ’(T), whose position does not
10000
81 MHz37 GHzmove with frequency. Our experimental data
exhibit relaxor ferroelectric behavior, because the1000
peak of ’(T) moves to higher T with increasing
frequency (see Fig. 1). Detail frequency analysis
1000
of dielectric dispersion revealed two anomalous
dielectric relaxations; one in sub-THz region andthe second in microwave and radio-frequency
100
region.
In contradiction to ceramics, we
300 325 350 375 400 425 450 475 500
observed two dielectric anomalies in PFN single
T(K)248
crystal , one at ~370K, and additional one,
Fig.
78:
Temperaturedependenceof the real andcoming from structural phase transition, at
imaginaryparts
ofdielectric
permittivityof PFN~355K. The rise of the dielectric permittivity
near the temperature of phase transitions is much ceramics.
sharper in single crystal than in ceramics, and thetemperatures of maxima of the dielectric permittivity do not depend on frequency, i.e. no relaxor ordiffuse phase transition behavior was observed.

247

V. A. Bokov, I. E. Mylnikova, and G. A. Smolenskii, “Ferroelectric antiferromagnetics”, Sov Phys–JETP, vol. 15, p.
447–449, 1962
248

A.Kania, E.Talik, and M.Kruczek, “X-Ray Photoelectron Spectroscopy, Magnetic and Dielectric Studies of
PbFe1/2Nb1/2O3 Single Crystals”, Ferroelectrics, vol. 391, p. 114-121, 2009

ISAF-P3C-15 ____________________________________________________________________________________________________________________

Microwave Dielectric Properties of DyScO3 and TbScO3
Substrates Measured by Thin Dielectric Resonator
Martin Kempa1, Valeriy Pashkov2, Viktor Bovtun1, Vitaliy Molchanov2, Stanislav Kamba1, Yuriy
Poplavko2, Yuriy Yakymenko2
1

2

Department of Dielectrics, Institute of Physics ASCR, Prague, Czech Republic
Department of Microelectronics, NTUU “Kyiv Polytechnic Institute”, Kyiv, Ukraine
Email: kempa@fzu.cz

Single-crystalline scandate substrates are widely used for deposition of the in-plane strained
epitaxial thin films with increased ferromagnetic and ferroelectric transition temperatures or
coexisting ferromagnetism and ferroelectricity249,2. Tentative applications of such films andheterostructures in electronics and telecommunication require knowledge of microwave dielectric
properties of both films and substrates. Recently we proposed the thin dielectric resonator (DR)consisting only of the dielectric substrate (or substrate and deposited film) for the non-destructive
electrode-free microwave characterization of thin films and substrates3. Their in-plane averaged
dielectric permittivity and losses can be measured using the TE01δ mode4,5. The HE11δ modes areproposed for the in-plane dielectric anisotropy characterization. Here we report new developments
and applications of the thin DR method for the anisotropic substrate characterization.
In-plane components of anisotropic microwave dielectric parameters of the (110) DyScO3 and (110)
TbScO3 substrates were measured from 10 K to 400 K. Their values and temperature dependences
are well consistent with the THz and infra-red parameters6, as well as with the permittivity
components along crystallographic axes measured at low frequencies7. Essential anisotropy of
microwave dielectric losses revealed at low temperatures is similar to that in THz range. A
pronounced maximum of dielectric losses is observed at 120-150 K.
DyScO3 and TbScO3 substrates do not satisfy fully to the strict requirements usual for microwave
applications: they are characterized by higher losses, strong anisotropy and pronounced temperaturedependence of their dielectric parameters. Nevertheless, the level of losses is still acceptable andallows use of unique properties of the strained films deposited on them.
249

D. Nuzhnyy, J. Petzelt, S. Kamba, P. Kužel, et al., “Soft mode behavior in SrTiO3/DyScO3 thin films: Evidence offerroelectric and antiferrodistortive phase transitions”, Appl. Phys Lett., vol. 95, 232902, p. 1-3, 2009.
2

J.H. Lee, L. Fang, E. Vlahos, X. Ke, Y.W. Jung, et al., ”A strong ferroelectric ferromagnet created by means of spin–lattice coupling”, Nature, vol. 466, p. 954-958, 2010.
3

V. Bovtun, V. Pashkov, M. Kempa, S. Kamba, et al., “An electrode-free method of characterizing the microwave
dielectric properties of high-permittivity thin films”, J. Appl. Phys., vol. 109, 024106, p. 1-6, 2011.
4

V. Skoromets, S. Glinšek, V. Bovtun, M. Kempa, J. Petzelt, et al., “Ferroelectric phase transition in polycrystalline
KTaO3 thin film revealed by terahertz spectroscopy”, Appl. Phys. Lett., vol. 99, No. 5, 052908, p. 1-3, 2011.
5

S. Kamba, V. Goian, M. Orlita, D. Nuzhnyy, J. H. Lee, et al., „Magnetodielectric effect and phonon properties ofcompressively strained EuTiO3 thin films deposited on (001) LSAT“, Phys. Rev. B, vol.85, 094435, p. 1-10, 2012.
6

S Kamba, V Goian, D. Nuzhnyy, V Bovtun, M. Kempa, J. Prokleska, M. Bernhagen, R. Uecker, D.G. Schlom „Polarphonon anomalies in single-crystalline TbScO3“ - Phase Transitions, vol. 86, p. 206–216, 2013.
7

S. Coh, T. Heeg, J.H. Haeni, M.D. Biegalski, J. Lettieri, L. F. Edge, et al., “Si-compatible candidates for high-k
dielectrics with the Pbnm perovskite structure”, Phys. Rev. B, vol. 82, 064101, p. 1-16, 2010.

ISAF-P3C-16 ____________________________________________________________________________________________________________________

Lattice distortions and Raman spectra of multiferroic
heterostructures
Yuzyuk Yury1, Khabiri Gomaa1,4, Anokhin Andrey1,2, Bunina Olga3, Stryukov Daniil1,3, Golovko
Yury2, Mukhortov Vladimir2, Shirokov Vladimir2
1
Faculty of Physics, Southern Federal University, Rostov-on-Don, Russia
Southern Scientific Centre, Russian Academy of Sciences, Rostov-on-Don, Russia
3
Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia
4
Faculty of Science, Fayoum University, Fayoum, Egypt
2

Email: yuzyuk@rumbler.ru
Multilayer films and superlattices (SLs) consisting of ferroelectric and multiferroic layers offer a very
efficient way of strain engineering to design materials with enhanced magnetoelectric responses. We
report on synthesis, x-ray diffraction (XRD) and Raman scattering characterization of epitaxial
heterostructures containing alternating (Bi0.98Nd0.02)FeO3 (BNFO) and (Ba0.8Sr0.2TiO3) (BST) layers deposited
onto (100) MgO substrates. Both layer thickness and number of deposited layers were varied with the aim
to investigate the lattice strains as a function of layers thickness.
XRD and Raman examinations were performed after deposition of each layer with aim to clarify
transformation of the lattice distortions at each step of growth. XRD patterns of multilayer BNFO/BST
heterostructures containing five relatively thick (80 nm) layers showed slightly shifted diffraction peaks ofboth parent materials due to their distortion. BST layers were found to be under compressive stress, while
BNFO sandwiched between two BST layers is under tensile stress. Significant shift of the E(TO) soft mode
corresponding to BST layers and partial depolarization in the Raman spectra of multilayer heterostructures
were observed due to lattice distortions imposed by epitaxial strains.
For heterostructures with the modulation periods smaller that 30 nm XRD patterns contain one central
peak (00l) located midway between respective BNFO and BST peaks and so-called satellite peaks typical formodulated structures – SLs. Detailed XRD examination revealed parallel “cube-on-cube” relationshipbetween each layer and substrate, both BST and BNFO layers are highly strained. In contrast to single BST
and BNFO films and heterostructures with relatively thick BNFO/BST layers, hardening of the soft mode andsignificant tilts and deformation of the FeO6 octahedra occurs in SLs and the symmetric-stretching mode of
FeO6 octahedra about 705 cm-1 appears in the Raman spectra. We propose that distortion in FeO6
octahedra is enforced by the epitaxial strains and induces enhanced magnetic properties recently
observed250 in BNFO/BST SLs with a few-nanometers modulation periods.

250

M. S. Ivanov, N. E. Sherstyuk, E. D. Mishina, A. S. Sigov, V. M. Mukhortov, and V. T. Moshnyaga, “Enhanced
magnetization and ferroelectric switching in multiferroic BST/BNFO superstructures,” Ferroelectrics vol. 433, p. 158163, 2012.

ISAF-P3C-17 ____________________________________________________________________________________________________________________

Fundamental Understanding of Structural Contributions to
Macroscopic Strain in Barium Titanate
Qinghua Cao1, John Daniels1
1

The School of Materials Science and Engineering, University of New South Wales, NSW, 2052
Australia
Email: z3300841@student.unsw.edu.au

The observation of enhanced strain obtained when fields are applied along non-polar directions inmany material compositions has led to the renewed study of classical ferroelectrics. In single
crystals, the piezoelectric properties at low fields can be attributed to the contribution of latticestrain (intrinsic strain) and field-induced domain wall motion (extrinsic strain). Both intrinsic andextrinsic mechanisms are highly anisotropic with crystallographic orientation. At higher fields,
crystallographic phase transformations may be induced which are proposed to generate theenhanced response. For future materials development it is necessary to understand the coupling of
anisotropic lattice strain and domain wall motion with the field induced phase transformations.
Strain mechanisms in Barium Titanate (BT) single crystals have been studied by several methods(i.e. PFM, SEM, and XRD). Here, we use neutron diffraction methods to allow us to probe theintrinsic, extrinsic and phase stability of BT, in-situ, from the bulk, with application of electricfields. The goal of this research is to characterize the anisotropy of both the intrinsic and extrinsic
contributions to macroscopic strain in Barium Titanate single crystals and directly measure thecrystallographic phase symmetry at each field step. This initially will lead to a more general
understanding of ultrahigh strains observed along non-polar directions, for which there is very little
structural experimental evidence.
[100], [110], [111] oriented BT crystals have been cut
into 1*1*1 mm cubes.
Macroscopic properties,
including strain and polarization have been measured.
The electric field applied on the samples is 2 kV/mm, 2.5
kV/mm, 3 kV/mm, respectively, in order to excite allstrain mechanisms including intrinsic, extrinsic, andphase transformations. Neutron diffraction measurements
were conducted at the High-Intensity Powder
Diffractometer at the Australian Nuclear Science andTechnology Organisation. Multiple reflections from eachcrystal were monitored at a sequence of increasing
electric fields.

Fig. 1 Intrinsic lattice strain of [100], [110],[111] oriented BT crystals

Macroscopic strain obtained on [100], [110], [111] oriented BT crystals, which is under unipolarelectric field, exhibits an increase trend. Intrinsic strain has been observed by the variation of latticespacing along the field direction (Fig. 1). Extrinsic domain wall motion is observed by variations of
the intensity ratios of ferroelastic twin peaks. Phase transformations were observed in [110], and[111] BT crystals at the fields of 1.5 kV/mm and 2 kV/mm, respectively. The results show that theextrinsic domains switching strain is dominant in [100], and [110], orientations at low fields, while
intrinsic effects are dominant in the [111] orientation. The crystallographic structure of the field
induced phases in [110] and [111] crystals will be discussed.

ISAF-P3C-18 ____________________________________________________________________________________________________________________

Formation Mechanism and Dielectric Properties of the KTiNbO5 andK3Ti5NbO14 Ceramics
1

Mir Im , Sang-Hyo Kweon , Guifang Han1, Sahn Nahma,1, Ji-Won Choi2 and Seong-Ju Hwang3
1

1

Department of Materials Science and Engineering, Korea University, Seoul 136-701, South
Korea

2

Electronic Materials Center, KIST 39-1 Hawolkok-dong, Seongbuk-gu, Seoul 137-791, South
Korea
3

Center for Intelligent Nano-Bio Materials (CINBM), Department of Chemistry and Nano
Sciences, Ewha Womans University, Seoul 120-750, South Korea
Email: mirueex@korea.ac.kr

TiNbO5 and Ti5NbO14 nano-films synthesized by KTiNbO5 and K3Ti5NbO14-layered compounds,
respectively, have been reported to exhibit a high εr with a low leakage current density.[1] Although
their dielectric properties have been reported, their structural and dielectric properties have not beenclearly investigated.[2] In order to fabricate a nano-film having good dielectric properties, it isnecessary to understand the microstructure and dielectric properties of the bulk layered perovskite
compounds. In this work, therefore, the formation process, the microstructure and dielectric
properties of the KTiNbO5 and the K3Ti5NbO14 oxides are systematically studied. A homogeneous
KTiNbO5 and K3Ti5NbO14 phases were formed at 900oC and the dense KTiNbO5 and K3Ti5NbO14
ceramics were obtained from the specimen sintered at 1150oC and 1125oC, respectively. Liquidphase-assisted abnormal grain growth occurred in both specimens along the directions
perpendicular to <002> during the sintering. Moreover, the secondary phases were developed in thespecimens sintered at high temperatures due to the evaporation of K2O.

The KTiNbO5 andK3Ti5NbO14 ceramics oxides sintered at 1150oC and 1125 oC, respectively, showed the highest
relative density of 96.0 % and 96.9% of the theoretical density. The detailed formation processes of
the KTiNbO5 and K3Ti5NbO14 ceramics and their dielectric properties will be also discussed in thiswork.

ISAF-P3C-19 ____________________________________________________________________________________________________________________

Infrared and terahertz study of lattice dynamics in PbTiO 3
Tetyana Ostapchuk1, Christelle Kadlec1, Petr Kužel1, Jiří Hlinka1, and Antoni Kania2
1

Department of Dielectrics, Institute of Physics, Academy of Sciences of the Czech Republic,
18221 Prague 8, Czech Republic
2
Institute of Physics, University of Silesia, Uniwersytecka 4, 40007 Katowice, Poland
Email: ostapcuk@fzu.cz

Recent success in understanding of the dynamics of the ferroelectric transition in PbTiO3xxiv,xxv stillrequires a straightforward interconnection of the lattice modes behavior with the macroscopic
dielectric characteristics. Here we present high-frequency dielectric spectra evaluated from the far
infrared reflectivity and time-domain terahertz transmission measurements. Their analysis enabled
us not only to get a full set of the polar mode parameters from the center of the Brillouin zone but
also to estimate the contribution of the lattice vibrations in the dielectric anomaly of PbTiO3
quantitatively.

ISAF-P3C-20 ____________________________________________________________________________________________________________________A Study of Properties of Ferrite - Ferroelectric Structures
for tunable electronic devices
A.V. Es'kov1 , А.A. Semenov2, A.I. Dedyk2, P. Yu. Beliavskiy2, Yu.V. Bogachev2, M.N. Knjazev2,
I.L. Mylnikov2, O.V. Pakhomov 1
1

Department of Cryogenic/ National Research University of Information Technologies, Mechanics
and Optics,St. Petersburg/ Russia
2
Physical Electronics & Technology Department / St. Petersburg Electrotechnical University LETI
(ETU), St. Petersburg/ Russia
Email: aeskow@gmail.com

Multiferroics are of great practical interest for modern microelectronics. In this study, we analyzed
two ways to obtain materials with multiferroic properties: 1) formation of multilayer structurescontaining ferroelectric and ferromagnetic films251 and 2) introduction of magnetic elements into
ferroelectric materials in concentrations sufficient for magnetic properties to appear in a composite
material252.
S21,
This work presents the results of multilayerdBstructures study such as Cu-Cr/BSTO/YIG/GGG-40
and the results of the investigation of influence of
Mn-ions concentration (0–20 wt.%) on dielectric-60
properties of Cu-Cr/BSTO/ -Al2O3 and Cu3
Cr/BSTO/GGG film structures. The structure and1-802composition of the samples were studied by meansof XRD and by analysis of XPS spectra. For the
5,8
6,0
6,2
6,4
6,6
6,8
f, GHzdetection of paramagnetic ions in the samples used
EPR spectroscopy. The measurements of Fig. 1: Experimental frequency characteristics of adielectrics characteristics of the planar capacitors ferrite-ferroelectric resonator.
were carried out at the frequencies 1 MHz and 6.44
GHz.

The optimal content of the Mn additive, as regards the dielectric properties (values of , tan,
tunability, and resistance), is 15 wt %. At this concentration of Mn in the film BST observed thegreatest change in the C-V characteristics of the structures Cu-Cr/BSTO/ -Al2O3 and CuCr/BSTO/GGG in a magnetic field H = 1570 Oe.
Figure 1 shows the tunability by changing of the magnetic field of the multi-layer ferriteferroelectric resonator based on the structure Cu-Cr/BST/YIG/GGG is about 75 MHz at a frequencyof 6.44 GHz. Curve 1 corresponds to zero strength of the control electric field and a magnetic fieldstrength of 1420 Oe; curves 2 and 3 were measured at a magnetic field strength of 1570 Oe, withthe electric field strength being zero for curve 2 and 5V/μm for curve 3. Influence of magnetic field

251

G. Srinivasan, S Dong, D Viehland, M Bichurin, C Nan, “Multiferroic magnetoelectric composites”, J. Appl.
Phys.,vol. 103, pp. 031101-35, 2008.
252

G.A. Smolenskiy, V.A. Bokov, V.A. Isupov, N.N. Krainik, R.E. Pasinkov, N.S. Shur, “Ferroelectrics andantiferroelectrics”, Nauka, L., 1971.

on the C-V characteristics of investigated structures and on the tunability of the resonator associatedwith magnetoelectric effect.

ISAF-P3C-21 ____________________________________________________________________________________________________________________

Structure and Multifunctionality of Strontium-Barium Niobate
Dec Jan1, Miga Seweryn1, Wokulska Krystyna1, Paszkowski Robert1, Świrkowicz Marek2,
Łukasiewicz Tadeusz2, Kleemann Wolfgang3
1

Institute of Materials Science, University of Silesia, Katowice, Poland
2
Institute of Electronic Materials Technology, Warsaw, Poland
3
Angewandte Physik, Universität Duisburg-Essen, Duisburg, Germany
Email: jan.dec@us.edu.pl

Solid solutions of the strontium-barium niobate SrxBa1-xNb2O6 where 0.25 < x < 0.8 (SBN) areenvironmental friendly (lead free) polar materials of oxygen octahedral family. This type ofmaterials is recognized as very prolific due to its five different cationic crystallographic sites.
Consequently, physical characteristics of SBN are strongly correlated to composition and chemicalbonding. As a result of the compositional flexibility, SBN is recognized to exhibit diverse
properties. Correspondingly, its potential applications are based on very attractive pyroelectric,
electromechanical, electro-optic, photorefractive, and nonlinear optical and dielectric properties.
Structurally strontium-barium niobate is distinguished by its open tungsten bronze structure, i.e. thecompound contains five AB2O6 formula units per tetragonal unit cell in which six A sites areoccupied by five divalent metal ions A. As a result the empty sites give rise to quenched electric
random fields even in the stoichiometric compound. Consequently, by changing the ratio between
strontium and barium components one may tune the system from ferroelectric (x < 0.5) to a genericrelaxor (x > 0.6) behavior while maintaining the structure unchanged253.
Using the Czochralski method eleven single crystalline compounds with nominal x = 0.26, 0.35,
0.40, 0.45, 0.50, 0.45, 0.61, 0.65, 0.70, 0.75, and 0.80 designated hereafter as SBN26, …, SBN80
have been grown. The crystals, grown along the [001] tetragonal direction, were up to 22 mm indiameter and 40 mm in length with characteristic 24 faces, free from striations and other extended
defects. Density of etch pits was found to be of the order of 102 – 103 cm-2.
Investigations of the linear dielectric response measured within 100  f  105 Hz along the polar caxis of the obtained single crystals reveal a gradual crossover from ferroelectric (SBN26) to utmost
relaxor-like (SBN80) behavior with a strong spatial anisotropy in the response. Complementary,
temperature dependences of the lattice parameters confirm existence of structural phase transitions
in all the investigated systems and conoscopic observations disclose an optical biaxiality for the
crystals with 0.75  x.
Financial support by MNiSW under grant N N507 455034 is gratefully acknowledged.

253

A. M. Glass, “Investigation of the Electric Properties…”, J. Appl. Phys., vol. 40, p. 4699 -4713, 1969.

ISAF-P3C-22 ____________________________________________________________________________________________________________________

Structural changes in the Y1-xCaxMnO3 solid solutions
Razumnaya A., Rudskaya A., Vlasenko M., Kupriyanov M.
Department of Physics, Southern Federal University, Rostov-on-Don, Russia
Email: razumnaya1@gmail.com
Solid solutions are usually used with the aim to modify properties of functional material based on
Mn-containing oxides. A well-known multiferroic YMnO3 are widely used as one of the basic
components of these solid solutions. Although in recent years Y1-xCaxMnO3 solid solutions systemwere studied in a number of articles254,255, the peculiarities of their structures is not yet understood.
The main feature of these solid solutions is the occurrence of the reconstructive transition from thehexagonal, typical for YMnO3, to orthorhombic structure at room temperature when the Caconcentration increases.
The purpose of this work was to investigate in details the structural changes in the Y1-xCaxMnO3
solid solutions as a function of Ca concentration in order to determine symmetry of phases, rangesof their concentration stability and variation of interatomic bond distances.
It is found that YMnO3 is characterized by hexagonal phase P63cm, as expected. It is shown that atroom temperature the concentration boundary between hexagonal P63cm and P63/mmc phases in Y1xCaxMnO3 solid solutions is located around x = 0.15. A reconstructive transition from hexagonal
P63/mmc phase to orthorhombic perovskite Pnma phase occurs in the concentration range
0.17 ≤ x ≤ 0.25. The compounds with x = 0.3; 0.5 belong to the orthorhombic perovskite Pnma
structure. In addition to the orthorhombic perovskite phase the cubic phase Pm3m coexists in thesample with x = 0.7.
As known, YMnO3 can be synthesized with the perovskite type structure only at high pressure256.
Alternatively, the formation of the perovskite phase in the Y1-xCaxMnO3 solid solutions with x ≥0.15 occurs at normal pressure. The observed at room temperature concentration phase transition in
the Y1-xCaxMnO3 solid solutions at x ~ 0.17 from the polar P63cm to nonpolar P63/mmc phase withthe emergence of the orthorhombic perovskite Pnma phase is an evidence of complicated structuralchanges.
A comparative analysis of the interatomic bond distances in the oxygen polyhedra of hexagonal andorthorhombic perovskite structures shows that the Mn-O bond distances are close in both structures.
Thus, reconstruction does not affect the interatomic distances in oxygen polyhedra considerably.
The results of preliminary measurements of the magnetic properties of the Y1-xCaxMnO3 solid
solutions are presented. The evidences of magnetic ordering at temperatures of about 50 K havebeen found.

254

M. N. Iliev, B. Lorenz, A. P. Litvinchuk, Y. Q. Wang, Y. Y. Sun, C. W. Chu, “Structural, transport, magnetic
properties and Raman spectroscopy of orthorhombic Y1−xCaxMnO3 (0≤x≤0.5)”, J. Phys.: Condens. Matter., vol. 17, p.
3333, 2005.
255

J. R. Sahu, C. R.Serrao, A. Ghost, A. Sundaresan, C. N. R. Rao, “Charge-order-driven multiferroic properties of Y 1-

xCaxMnO3”, Solid State Commun., vol. 149, p. 49-51, 2009.
256

V. E. Wood, A. E. Austin, E. W. Collings, “Magnetic properties of heavy-rare-earth orthomanganites”, Phys. Chem.
Solids., vol. 34, p. 859-868, 1973.

ISAF-P3C-23 ____________________________________________________________________________________________________________________

Raman spectroscopy of Sodium Bismuth Titanate ceramics
Marco Deluca1,2, Denis Schütz3, Elena Aksel4, Gunnar Picht5,6, Humberto M. Foronda4, Antonio
Feteira7, Klaus Reichmann3, Kyle Webber8 and Jacob L. Jones4
1

Materials Center Leoben Forschung GmbH, Leoben, Austria
Institut für Struktur- und Funktionskeramik, Montanuniversitaet Leoben, Leoben, Austria
3Technische Universität Graz, Graz, Austria
4
Department of Materials Science and Engineering, University of Florida, Gainesville, FL, USA
5
Robert Bosch GmbH, Stuttgart, Germany
6
Institute of Applied Materials, Karlsruhe Institute of Technology, Karlsruhe, Germany
7
Sheffield Hallam University, Sheffield, UK
8Technische Universität Darmstadt, Darmstadt, Germany
2

Email: marco.deluca@mcl.at
Sodium Bismuth Titanate (NBT) is a room-temperature ferroelectric perovskite currently being
considered as the basis for possible lead-free substitutes for Lead Zirconate Titanate (PZT)
piezoelectrics in actuators. This interest is motivated by the discovery of a large field-induced strain
in NBT-based compositions, surpassing that of commercial PZT257. These properties, however,
persist above the depolarization temperature Td, where the material is in a long-range nonferroelectric state. The obvious differences with PZT have triggered a large amount of structural
studies on NBT and its modifications, mostly by x-ray diffraction (XRD), transmission electron
microscopy (TEM) and Raman spectroscopy. XRD studies generally revealed a pseudocubic
structure above Td, whereas the Raman signal points to the presence of local disorder258. TEM
observations further confirmed the presence ofnanostructured phases within the same grain in
NBT259.
In this work, temperature- and field-dependent
Raman spectroscopy measurements on several
NBT compositions substituted with Fe, Barium
Titanate (BT) and Potassium Bismuth Titanate(KBT) will be presented and discussed together
with the results of dielectric, electro-mechanicaland synchrotron XRD measurements. Raman
spectroscopy offers the unique advantage ofbeing a non-destructive, laboratory-scaletechnique that reveals short-range information, Fig. 79: Room-temperature Raman spectra of pure,undoped NBT, NBT with 13% and 90% BT (NBT13BT and NBT-90BT, respectively), and pure BT.
257

S.-T. Zhang, A. B. Kounga, W. Jo, C. Jamin, K. Seifert, T. Granzow, J. Rödel, D. Damjanovic, “High-strain leadfree antiferroelectric electrostrictors”, Adv. Mater., vol. 21, p. 4716-4720, 2009.
258

E. Aksel, J. S. Forrester, B. Kowalski, M. Deluca, D. Damjanovic, J. L. Jones, “Structure and properties of Femodified Na0.5Bi0.5TiO3 at ambient and elevated temperatures”, Phys. Rev. B, vol. 85, p. 024121-1-11, 2012.
259

L. A. Schmitt, H.-J. Kleebe, “Single grains hosting two space groups – a transmission electron microscopy study of alead-free ferroelectric”, Funct. Mat. Lett., vol. 3, p. 55-58, 2010.

complementary to the aforementioned techniques.

ISAF-P3C-24 ____________________________________________________________________________________________________________________

Broadband Dielectric Spectroscopy and the Application of
Lichtenecker Mixing Formula for Barium Titanate and NickelZinc Ferrite Composite Ceramics
Aurimas Sakanas1, Robertas Grigalaitis1, Jūras Banys1, Liliana Mitoseriu2, Vincenzo Buscaglia3,
Paolo Nanni4
1Faculty of Physics, Vilnius University, Vilnius, Lithuania
Physics Department, University “Alexandru Ioan Cuza”, Iasi, Romania
3
Institute of Energetics & Interphases, IENI-CNR, Genoa, Italy
4
Department Chemical & Process Engineering, University Genoa, Genoa, Italy
2

Email: aurimas.sakanas@ff.vu.lt
Many theoretical approaches exist to describe properties of composite materials, according to thevolume fraction of the component phases. The effective medium approximation (EMA) models are
the most suitable for such analysis and one of the approximations are Lichtenecker mixing
formulae260, allowing to calculate the effective macroscopic response of the composite mixture
according to its constituents.
Multiferroic barium titanate and nickel-zinc ferrite composite ceramics, having chemical formulaxBaTiO3-(1-x)Ni0.5Zn0.5Fe2O4 with the volume fractions x=0.466, 0.567 and 0.67, were investigatedadapting the broadband dielectric spectroscopy methods in 20 Hz to 50 GHz frequency range and in
100 K to 500 K temperature range. The results obtained indicate the preserved properties of purebarium titanate with the noticeable conductivity
contribution, caused by the ferrite phase of the 1600
composite.
Barium Titanate
1400

Nickel-Zinc Ferrite'In the present contribution, the approximation of 1200
the experimental effective permittivity data of thecomposite ceramics using Lichtenecker mixing 1000
800
formula will be proposed. Computed dielectric
permittivity values for barium titanate and nickel600
zinc ferrite at 100 MHz frequency (Fig. 1)
400
manifest the presence of three peaks
200
corresponding to phase transitions of barium
titanate at approximately the same temperatures
0
100 150 200 250 300 350 400 450 500 550
known from the classical experimental results
T (K)with the values of dielectric permittivity being
Fig. 80: The real part of dielectric permittivity ofrealistic for barium titanate ceramic materials.
barium titanate and nickel-zinc ferrite at 100 MHz
Nickel-zinc ferrite exhibits much lower dielectric frequency, calculated from the experimental results
permittivity values showing almost no
using Lichtenecker mixing formuladependency on the temperature.
260

T. Zakri, J. P. Laurent, M. Vauclin, “Theoretical evidence for ‘Lichtenecker’s mixture formulae’ based on theeffective medium theory”, J. Phys. D: Appl. Phys., vol. 31, p. 1589-1594, 1998.

ISAF-P3C-25 ____________________________________________________________________________________________________________________

LiNbO3-LiTaO3 mixed crystals:
A joint theoretical and Raman investigation

S. Neufeld1, S. Sanna1, A. Riefer1, M. Grothe1, G. Berth1, A. Zrenner2,1,
H. Zhang3 and W. G. Schmidt1
1

2

Universität Paderborn, 33098 Paderborn, Germany
Center for Optoelectronics and Photonics Paderborn (CeOPP), 33098 Paderborn, Germany
3
State Key Lab of Crystal Materials, Shandong University, Jinan 250100, Chinae-mail: simone.sanna@uni-paderborn.de

Mixed crystals have recently attracted the attention of the scientific community, as they offer the
possibility to tune the physical properties by varying the composition. Lithium niobate-tantalate(LNT) is one of the simplest ferroelectric mixed crystals, which shows quite unusual physicalproperties. In particular, the existence of a composition with zero birefringence at room temperatureis unique in ferroelectric nonlinear-optical materials. Indeed within this composition the crystal is
optical isotropic and yet electrically polar [1,2].
Despite the huge potential in electro-optic and acousto-optic devices and the extensive use of theend-compounds LN and LT, relatively few is known about the mixed crystals [3,4]. In thiscontribution, we characterize LiNb1-xTaxO3 over a wide composition range by the combined
approach of first-principles simulations in the framework of the density functional theory and
Raman spectroscopy.
Structural parameters (such as volumes and lattice constants) show a Vegard-like behaviour
between the end-compounds LN and LT, while the electronic band gap shows pronounced
deviations from the linearity. Measured Raman spectra and frequencies predicted from thetheoretical models are compared. In particular, the frequency and intensity dependence of the fourA1-TO modes on the crystal composition is discussed and explained on the basis of the phonon
eigenvectors calculated within the density functional theory. Based on our result, we show that the
LNT composition can be quite accurately estimated by its vibrational properties.
[1] I. G. Wood, P. Daniels, R. H. Brown and A. M. Glazer, J. Phys.: Cond. Mat. 20, 235237 (2008).
[2] A. Bartasyte, A. M. Glazer, F. Wondre, D. Prabhakaran, P. A. Thomas, S. Huband, D. S. Keeble, S.
Margueron, Mat. Chem. Phys., 134, 728 (2012).
[3] S. Margueron, A. Bartasyte, A. M. Glazer, E. Simon, J. Hlinka, I. Gregora, and J. Gleize, J. App.
Phys. 111, 104105 (2012).
[4] D. Xue, K. Betzler, H. Hesse, Solid State Communications 115, 581(2000).

ISAF-P3C-26 ____________________________________________________________________________________________________________________

High-Temperature X-ray Diffraction of Ca3TaGa3Si2O14 and
La3Ga5SiO14 Piezoelectric Crystals Excited by Surface Acoustic
Waves
Luc Ortega1, Dmitry Roshchupkin2, Dmitry Irzhak2, Ivo Zizak3
1

Laboratoire de Physique des Solides, Univ. Paris-Sud, CNRS, F-91405 Orsay, France
2
Institute of Microelectronics Technology and High-Purity Materials,
Russian Academy of Sciences, 142432 Chernogolovka, Russia
3
BESSY GmbH, Albert-Einstein Str. 15, D-12349 Berlin, Germany
Email: ortega@lps.u-psud.fr

Ca3TaGa3Si2O14 (CTGS) and La3Ga5SiO14 (langasite: LGS) crystals are promising piezoelectricmaterials for acoustooptics, acoustoelectronics and optoelectronics. They can be used to produce
electroacoustic devices at high temperature due to their high thermal stability; for example LGS
exhibits no phase transition up to 1470°C. The process of Surface Acoustic Wave propagation inthese crystals is investigated using diffraction techniques since x-ray radiation is sensitive to the
crystal lattice distortions. The SAW propagation at the surface crystal produces the sinusoidal
modulation of the crystal lattice, which leads to the appearance of diffraction satellites around a
Bragg peak (figure 1). SAW amplitudes and wavelengths can be deduced from the satellites
intensities and their angular positions261.
X-ray diffraction rocking curves of acoustically modulated
crystals were studied at x-ray energy of 11 keV (near Ga Kedge and Ta L-edge) in the kinematical diffraction
conditions (x-ray penetration depth is smaller than the SAW
penetration depth). Experiments were performed at the
KMC2 beamline of the synchrotron source BESSY II in
Berlin.
Fig. 81: Experimental principle of a surface
acoustic wave device for x-ray diffraction.

261

We report, for the first time, temperature characteristics ofsurface acoustic wave propagation using x-ray diffraction
method. To follow the change of the diffraction profiles insitu during heat treatments, the samples with iridium madetransducers were placed on a heater inside a hemispherical
Be window under high-vacuum conditions. Measurements
were carried out at temperatures that gradually increased
from room temperature up to 400°C. Rocking curves infigure 2 show the change of SAW propagation withtemperature for a fixed excitation. We analyzed thefrequency response at each temperature for CTGS and LGS
single crystals.

Fig. 2: X-ray rocking curves of CTGS fromRT to 350°C with fixed excitation conditions;
D.V. keV;
Roshchupkin,
D.V.
Irzhak, R. Tucoulou, O.A. Buzanov, “X-ray Bragg diffraction from langasite crystal
E=11
=6 µm; (110)reflection.

modulated by surface acoustic wave”, J. Appl. Phys., vol. 94 p. 6692-6696, 2003.

Other SAW and piezoelectric characteristics such as the power flow angle can be determined using
this method.

ISAF-P3C-27 ____________________________________________________________________________________________________________________

Effects of γ-ray irradiation on ferroelectric properties of Pr and
Mn co-substituted BiFeO3 thin films
Zheng Wen1,2,3, Chunyan Zheng3, Jin Li3, Lijun He3, Jiating Zhu4, Di Wu1,2, Aidong Li1,2
1

National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
Department of Materials Science and Engineering, College of Engineering and Applied Scienes,
Nanjing University, Nanjing 210093, China
3
Key Laboratory of Ningxia for Photovoltaic Materials, Ningxia University, Yinchuan 750021,
China
4
Agricultural Application of Nuclear-Radiation-Research Team, Jiangsu Academy of Agriculture
Science, Nanjing 210014, China
2

Email: diwu@nju.edu.cn
Polycrystalline Pr and Mn co-substituted BiFeO3 (BPFMO) thin films are deposited on
Pt/TiO2/SiO2/Si substrates by chemical solution deposition. Pt/BPFMO/Pt capacitors were
subjected to 1.33-MeV γ-ray irradiation from a60
Co source for 24 hours, which results in total
dose of 5.0 Mrad. γ-ray irradiation effects on
ferroelectric properties of BPFMO thin films areinvestigated by polarization-voltage hysteresis
measurements
andpiezoresponse
force
microscopy. The irradiated BPFMO capacitors
get imprinted and show reduced switchable
polarizations. The shift of hysteresis loops(imprint) depends on the direction of polarization
prior to irradiation. And the loss of switchable
polarization
increases
withdecreasingpolarization value prior to irradiation. These are
discussed in terms of separation of γ-ray-excitedelectron-hole pairs and subsequent charge
trapping and aggregation on electrode/film
interfaces and domain walls. Charge aggregation Fig. 82: Hysteresis loops recorded before and after
on electrode/film interfaces gives rise to an extra irradiation for Pt/BPFMO/Pt thin-film capacitors
internal electric field to stabilize the polarization poled to positive (a) and negative (b) polarizations.
and results in a shift of hysteresis loops along the Corresponding internal electric field components arehorizontal axis, while charge trapping on domain illustrated schematically in (d) and (e) for thewalls blocks domain switching and results in the positively and negatively poled capacitors, where /symbols represent γ-ray-excited holes andobserved polarization degradation.
electrons, respectively.

ISAF-P3C-28 ____________________________________________________________________________________________________________________

Resonance Line Shape Behavior of 2-2 Magnetoelectric
Sensors on Cantilever Substrates
Jascha Lukas Gugat1, Matthias C. Krantz1, Martina Gerken1
1

Institute of Electrical and Information Engineering,
Christian-Albrechts-Universität zu Kiel, Germany
Email: jlg@tf.uni-kiel.de

We investigate theoretically the influence of substrate thickness on the resonance line shape of
bilayer magnetoelectric (ME) sensors calculated using the finite element method (FEM).
Recent research on magnetoelectric sensors based on multiferroic composites described pico-Tesla
AC magnetic field sensitivity262 and nano-Tesla DC magnetic field sensitivity.263 Further
enhancements in sensitivity are achieved for sensors consisting of a magnetostrictive (MS) and apiezoelectric (PE) phase by operation atmechanical resonance.264 Due to their potential
small
scale,
inexpensive
wafer-based
manufacturing process, and operation at room
temperature such thin-film based ME sensors
are of particular interest for biomagnetic
applications. The MS layer is frequency
dependently deformed by a magnetic field. Due
to elastic coupling the deformation istransferred to a strain in the PE layer inducing a
voltage signal.
The small signal behavior of layered cantileverME sensors is simulated using 2D FEM with alinear material model. Cantilevers consisting of Fig. 83: Induced electric potential across the PE layer
a 2.5 µm high Terfenol-D (MS) layer on top of as a function of frequency for different cantilevera 2.5 µm high PZT (PE) layer on top of a substrate thicknesses. Inset: Schematic of investigatedsilicon substrate with a total length of 300 µm magnetoelectric sensor structure.
and varying thickness are considered. These are
typical dimensions for micro-electro-mechanical systems (MEMS) sensors.265 Fig. 1 shows theinduced electric potential across the PE layer as a function of frequency in the range of the firstbending mode for different substrate thicknesses. The resonance line shapes are asymmetric anddependent on the substrate thickness. A zero response frequency is observed either below or above
262

S. X. Dong, J. Y. Zhai, F. Bai, J. F. Li, and D. Viehland, “Push-pull mode magnetostrictive/piezoelectric laminate
composite with an enhanced magnetoelectric coefficient,” Appl. Phys. Lett. 87, 062502 (2005)
263

S. X. Dong, J. Y. Zhai, J. F. Li, and D. Viehland, “Small DC magnetic field response of magnetoelectric laminate
composites,” Appl. Phys. Lett. 88, 082907 (2006)
264

H. Greve, E. Woltermann, R. Jahns, S. Marauska, B. Wagner, R. Knöchel, M. Wuttig, and E. Quandt, “Lowdamping resonant magnetoelectric sensors,” Appl. Phys. Lett. 97, 152503 (2010)
265

S. Marauska, R. Jahns, H. Greve, E. Quandt, R. Knöchel, and B. Wagner, „MEMS magnetic field sensor based onmagnetoelectric composites,” J. Michromech. Microeng. 22, 065024 (2012)

the resonance frequency. These results may be explained by considering the mechanical stress andstrain distributions in the cantilever structure.

ISAF-P3C-29 ____________________________________________________________________________________________________________________

Infrared and Terahertz Spectroscopy of Epitaxial
BaTiO3/SrTiO3 Superlattices
V. Železný1, Ch. Kadlec1, A. Soukiassian2, X.X. Xi3, D.G. Schlom2
Institute of Physics, ASCR, Na Slovance 2, 182 21 Praha 8, Czech Republic2
Department of Materials Science and Engineering, Cornell University, Ithaca, New York, 148531501, USA
3
Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
1

Email: zelezny@fzu.cz
Crystal lattice dynamics brings fundamental information for understanding the physical propertiesof ferroelectrics. Infrared spectroscopy is a very effective tool for studying and understanding the
behavior of ferroelectrics because the incident radiation couples directly to the order parameter(polarization). This can be used for the direct extraction of the dielectric function and determinationof the parameters important for lattice dynamics. Thin films and superlattices are more suitable fordevice application, but they show difference in their behaviour compared bulk materials. Varying
temperature enables us to study nanoscale ferroelectric heterostructures in the vicinity of the phasetransition.
The infrared reflectivity and terahertz transmission measurements were performed on fullycommensurate [(BaTiO3)8/(SrTiO3)4]40 superlattices grown by molecular-beam epitaxy on scandate
substrates. The experimental spectra were measured in two polarizations along the c axis andperpendicular to it on the (110) cut of SmScO3 substrate. The Drude-Lorentz form of the dielectric
function was used for both substrate and superlattice. First we fit the spectrum of the bare substratethen we fixed all of its parameters. Adding the top layer to the model and fitting the total system(substrate + superlattice), we could determine the effective parameters of the superlattice. A further
refinement of the dielectric function was done using a variational dielectric function procedure,
which provides the dielectric function in a non-parametrized form. The resulting dielectric function
is of perovskite-like character with three dominating vibration modes. Combining these approaches
enabled us to observe the soft mode and extract its parameters. The temperature behavior of themodes and their parameters were also studied. The obtained results demonstrate that the softeningof the soft mode is much smaller than for the bulk materials of the superlattice components.
This work was partially supported by Grant Agency of the Czech Republic under Contract No.
204/11/1011.

ISAF-P3C-30 ____________________________________________________________________________________________________________________

Measurement of the indirect piezoelectric coefficient of thinfilms using interferometry
Mark Stewart 1 and Markys G Cain11

National Physical Laboratory, Teddington, Middlesex, UK
Email: mark.stewart@npl.co.uk

Piezoelectric thin films are a promising high force actuation technology for MEMS devices. At
present materials are still at the research stage, with very few Fab plants offering piezoelectricmaterials as a standard option. Users and manufacturers of these films want to assess the quality of
the films at an early stage in production, so there is a requirement to be able to measure thepiezoelectric coefficient of films as produced on a substrate.
In the late 90’s Kholkin et al266 showed that many measurements of the piezoelectric output of thinfilms suffered from bending effects, resulting in inflated values. To overcome this they proposed the
double beam interferometer method which became the de facto ‘standard’. More recently theavailability of microscope based laser Doppler vibrometers have led workers to re-evaluate the useof single sided measurements, where the sample bending is eliminated by adhesive bonding to arigid substrate.
This work will compare both experimental methods and with the aid of FEA examine the effects ofvarious realistic boundary conditions on observed and predicted output.

266

A. L. Kholkin, Ch. Wütchrich, D. V. Taylor, and N. Setter, “Interferometric measurements of electric field‐induced
displacements in piezoelectric thin films”, Rev. Sci. Instrum. 67, 1935, 1996.

ISAF-P3C-31 ____________________________________________________________________________________________________________________

Hybrid improper ferroelectric phase transition in Ca3Mn2O7

S. Kamba1, V. Goian1, C. Adamo2, P. Vaněk1, J. Drahokoupil1, A. Mould3, H. Seiner4,
L. Palatinus1, M. Klementová1, M. Svatuška1, N.A. Benedek5, and D.G. Schlom2,61
Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic2
Department of Materials Science and Engineering, Cornell University, Ithaca, New York, USA
3
Department of Materials Science and Engineering, University of Sheffield, Sheffield, UK
4
Institute of Thermomechanics, ASCR, Prague, Czech Republic
5
Materials Science and Engineering Program, The University of Texas at Austin, Texas, USA
6
Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York, USA
Email: goian@fzu.cz
Based on ab initio calculations, a new type of ferroelectric phase transition was recently proposed in
Ca3Mn2O7, which crystallizes in Ruddlesden-Popper structure.267 The ferroelectricity in such systemshould be induced by freezing of two nonpolar phonons from Brillouin zone boundary. If the modesof X 2 and X 3 symmetries will freeze simultaneously, I4/mmm phase will transform directly to
A21am orthorhombic structure and the phase transition is called the hybrid improper ferroelectricphase transition. If the modes will freeze gradually, paraelectric I4/mmm phase should transform tointermediate Cmcm ( X 3 mode freezes first) or Cmca phase ( X 2 mode freezes first) and after
freezing of the second parameters, the ferroelectric A21am orthorhombic structure will finallyappear. The same calculations have shown that in biaxially strained Ca3Mn2O7 films, the switchingof polarization by electric field should cause 180o flip of magnetic moments by reversing theoctahedral tilt. 267
The aim of this contribution is to determine whether Ca3Mn2O7 undergoes one hybrid or two
successive phase transitions. We have combined X-ray and electron diffraction with measurementsof thermal expansion, resonant ultrasound and infrared (IR) spectroscopy. We investigated bothbulk ceramics and strained Ca3Mn2O7 thin films deposited using reactive molecular beam epitaxyon (110)LuAlO3 and (110)YAlO3 substrates (compressive strain up to 1.5 %).
Our room temperature electron and X-ray diffraction studies confirm A21am crystal structure, which
could be ferroelectric, but rather high conductivity of the ceramics did not allow us to performmeasurements of ferroelectric hysteresis loops or temperature dependence of radio-frequency
permittivity. X-ray diffraction reveal abrupt change near 670 K, thermal expansion coefficientexhibits the structural phase transition at 690 K IR spectra of ceramics and thin films support
improper-ferroelectric character of the phase transition near the same temperature. However,resonant ultrasound spectra of ceramics revealed two phase transitions; first one near 650 K andsecond one near 770 K. Details high-temperature structural studies, which should determine theintermediate and high-temperature structure symmetries, are in progress.

267

N. Benedek N. and C.J. Fennie, Hybrid improper ferroelectricity: A mechanism for controllable
polarization-magnetization coupling, Phys. Rev. Lett., vol. 106, p. 107204, 2011.

ISAF-P3C-32 ____________________________________________________________________________________________________________________

Microwave Characterization of Tunable InterdigitatedCapacitors on BTS Thin Films deposited by sol-gel
Waldhoff Nicolas1, Fasquelle Didier1, Blary Karine2 et Carru Jean-Claude1
1

2

UDSMM Laboratory, ULCO, 50 rue F. Buisson, BP717 - 62228 Calais
IEMN, Université de Lille1, avenue H. Poincaré, 59652 Villeneuve d’Ascq
Email: nicolas.waldhoff@eilco-ulco.fr

The strong dependence of the dielectric permittivity of ferroelectric materials under electric field
ensures that they are particularly attractive for microwave applications. Moreover, by using
interdigitated capacitors, which allow the extraction of different characteristics such as thetunability or the dielectric loss, they also offer the opportunity to deposit ferroelectric films on
insulating substrates like sapphire, and owning excellent High Frequencies (HF) properties.
Nowadays, many developments are migrating to BaTiO3 (BT) materials. However, their use in HF
applications is limited by their losses. To overcome this problem, without affecting the electricalperformance, the BT material can be doped with strontium or tin268.
The BaTi0.98Sn0.02O3 (BTS) solutions were prepared by a sol-gel method using barium acetate, tinacetate and titanium isopropoxide as starting materials. BTS films were then deposited onto
sapphire substrates by spin coating. Two samples were realized. Crystallization was achieved via
post deposition annealing at 750°C (named BTS750) during 1 hour for the first sample and at
950°C (named BTS950) during 15 min for the second. Interdigitated electrodes were then depositedon the film surface by a lift-off process and gold
F=67 GHz
Accordability BTS950 = 15,4%160
sputtering.
140

Capacitance (fF)

The interdigitated structures were measured inreflection with coplanar accesses and quasi-TEM
transmission line. Based on a de-embedding (DE) method derived from the extraction techniqueof silicon transistors2, OPEN and SHORT
structures were realized to perform D-E on thecapacitances.

120
100

Capa_D3_BTS750
CapaOS_D3_BTS750
Capa_D3_BTS950
CapaOS_D3_BTS950
Accordability OS BTS950 = 28%8060

Accordability BTS750 = 26 %40

Two samples were characterized using S
parameters measurements up to 67 GHz. The
-20
-10
0
10
20
Electrical field (V)Figure 1 compares the same capacitance on both
samples with and without OPEN-SHORT D-E. At Fig. 84: Interdigitated capacitances (BTS750 and
67 GHz, after D-E, the tunability is similar (26 BTS950) evolutions at 67 GHz with and without
and 28%). At 250 MHz (not presented here), the OPEN-SHORT structure versus electrical field.
tunability reaches 50%. Other structures were268

J. – C. Carru et al, “Electrical Characterization of lead free Sr and Sn doped BaTiO3 ferroelectric films deposited bysol-gel”, FERROELECTRICS book by INTECH (Rijeka, Croatia), chapter 3, pp. 49-72, June 2011.
2

N. Waldhoff, et al, « Improved Characterization Methology for MOSFETs up to 220 GHz », Microwave Theory andTechniques, IEEE Transactions on, vol. 57, no 5, p. 1237 ‑1243, may 2009.

analyzed. The variation of their planar electrodes dimensions was investigated along with various
characteristics which will be presented.

ISAF-P3C-33 ____________________________________________________________________________________________________________________

Far-infrared and THz spectroscopy in thick PZT films
Elena Buixaderas1, Christelle Kadlec1, Volodymyr Skoromets1, Dmitry Nuzhnyy1, Jan Petzelt1,
Hana Ursic2, Barbara Malic2
1

Department of Dielectrics, Institute of Physics, ASCR, Prague, Czech Republic
Department of Electronic Ceramics, Jožef Stefan Institute, Ljubljana, Slovenia

2

Email: buixader@fzu.cz
Pure and dense highly tetragonal ceramics of Pb(Zr1-xTix)O3 (PZT 100x/100(1-x)) are quite hard togrow, which is a problem for the study of the real PZT system. The great strain anisotropy between
the polar axis and the plane perpendicular to it creates high stresses within domains and grains insamples with x > 0.60 and these ceramics tend to break apart. Usually, to obtain dense tetragonal
PZT ceramics some extra components have to be added during the fabrication process at least in asmall amount.
To overcome this problem without adding any extra atom to the lattice, which could affect thedielectric behaviour of the samples and/or their phonons, pure PZT films can be deposited onsuitable substrates. In this work, thick PZT films were deposited by screen printing on sapphire
substrates (c-cut) for two compositions (36/64 and 38/62) and subsequent sintering at different
temperatures for two hours. The resulting films
had thicknesses between 23 and 30 m.
0.8

The flatness and porosity together with theoverall phonon response of the films were
tested measuring the far-infrared (FIR)
reflectivity spectra. Dielectric response below
phonons was measured using transmission
time-domain terahertz spectroscopy.

0.7

PZT 38/62

29 m
30 m

0.6

Reflectivity

In order to analyze the homogeneity of thefilms Raman maps were taken at room
temperature and compared with spectra on
dense ceramics of similar compositions.

0.5
0.4
0.3
0.2
0.1

Results are compared with dielectric data
0.0
0 100 200 300 400 500 600 700 800 900 1000
already measured on bulk tetragonal PZT-1Wavenumber (cm )269
42/58.
The effect of porosity has been
evaluated using the Bruggeman effective Fig. 85: FIR and THz reflectivity of the PZT 38/62
films on sapphire at room temperature.
medium approach.
Authors would like to thank Silvo Drnovšek and Kostja Makarovič for help during the processingof the samples.
269

E. Buixaderas et al, “Lattice dynamics and dielectric response of undoped, soft and hard PbZr 0.42Ti0.58O3”, Phase
Transitions, vol. 83, p. 917-930, 2010.

ISAF-P3C-34 ____________________________________________________________________________________________________________________

Anisotropic electrical properties of BNT based textured lead-free piezoceramics
Haibo Zhang, Wook Jo, Jürgen Rödel
Institute of Materials Science, Technische Universität Darmstadt, 64287 Darmstadt, Germany
Lead-free piezoelectric materials have been the subject of ongoing experimental andtheoretical investigations due to their fundamental scientific interest and their importance intechnological applications. Various lead-free piezoceramics have been considered as candidates for
replacing Pb-based piezoceramics during the past decades. Bismuth sodium titanate,(Bi1/2Na1/2)TiO3 (BNT), is considered to be an excellent candidate as a key lead-free piezoelectricmaterial, because it forms a solid solution with BaTiO3 (BT) or Bi1/2K1/2TiO3 (BKT) showing
improved dielectric and piezoelectric properties at the rhombohedral-tetragonal morphotropic phaseboundary (MPB). Recently, a giant strain of 0.45% was observed in BNT-BT-2KNN (with 2 mol%
KNN) ceramic at room temperature, which is higher than the strain of a commercial soft PZT
ceramic (PIC151, PI Ceramics). However, the giant strain can only be realized at very high electricfields (>6 kV/mm), which should be reduced before it can be considered for industrial applications.
It is well known that physical properties of piezoelectric ceramics strongly depend on the
microstructure. Piezoelectric single crystals show enhanced performance as compared topolycrystalline ceramics. As a consequence, textured piezoceramics are expected to possess
improved piezoelectric properties due to cooperating domains with uniformly aligned polarizations.
Most recently we found the poling field in textured BNT based piezoceramics is much lower thanthat in random piezoceramics. In the present work, the BNT based piezoceramics were prepared by
the templated grain growth (TGG) technique. The processing route is to be improved to get highly
textured piezoceramics with various phase structures. The high degree of orientation (Lotgeringfactor f > 90%) was achieved. The dielectric properties, ferroelectric properties and the bipolar andunipolar strain of the textured piezoceramics were measured, analyzed and compared with those ofcommon bulk materials. Moreover, a special attention will be paid to the anisotropic electricalproperties using textured samples cut at different angles.
Reference:
1. Zhang, S. T., Kounga, A. B., Aulbach, E., Granzow, T., Jo, W., Kleebe, H. J., and Rödel, J. Lead-freepiezoceramics with giant strain in the system Bi0.5Na0.5TiO3-BaTiO3-K0.5Na0.5NbO3 I. Structure and room
temperature properties. J. Appl. Phys., 2008, 103, 034107.
2. Seifert, K. T. P., Jo, W., and Rödel, J. Temperature-insensitive large strain of (Bi1/2Na1/2)TiO3(Bi1/2K1/2)TiO3-(K0.5Na0.5)NbO3 lead-free piezoceramics. J. Am. Ceram. Soc., 2010, 93, 1392-1396.
3. Jo, W., Dittmer, R., Acosta, M., Zang, J., Groh, C., Sapper, E., Wang, K., and Rödel, J. Giant electricfield-induced strains in lead-free ceramics for actuator applications–status and perspective. J.
Electroceram., 2012, 1-23.

ISAF-P3C-35 ____________________________________________________________________________________________________________________

The frequency and temperature dependence of hysteresis loop inP(VDF-TrFE) copolymer films
Manfang Mai1, Andreas Leschhorn1, Herbert Kliem1
1Institute of Electrical Engineering Physics, Saarland University, Saarbruecken, Germany
Email: manfangmai@mx.uni-saarland.de

The experimental hysteresis loop of ferroelectric poly(vinylidenefluoride-trifluoethylene) [P(VDFTrFE)] copolymer films is measured in a wide frequency and temperature range. For extrinsic
switching, ferroelectrics in general do not exhibit well-defined coercive fields. There are three
regions in the frequency dependence of coercive field. Below 1 Hz, the coercive field gets to asaturation. In the lower frequency region from 1 Hz to 5 kHz, the hysteresis loop widens and thecoercive field increases with increasing frequency while the remanent polarization is almost
constant. As frequency increases, the excitation field changes faster than the dipole switching. The
dipoles become more difficult to catch up with the external signal and a higher coercive field is
expected. A linear fit of the frequency dependence of Ec in the log-log scale plot gives an exponent
value of 0.04. In the higher frequency region from 5 kHz to 1 MHz where the switching time islonger than half of the external signal period, switching is suppressed and the amount of theswitchable polarization depends on the frequency. The hysteresis loop starts to shrink and thecoercive field decreases with increasing frequency. For a constant frequency, the hysteresis loop
measured at different temperature exhibits a linear decrease of coercive field with increasing
temperature. A double hysteresis loop is observed close to the Curie point and a sharp jump of theremanent polarization is obtained in samples as thick as 600nm indicating a first order phasetransition. For samples as thin as 90nm, the double hysteresis loop of the polarization is absent andthe change of remanent polarization on temperature is smoother.
The above experimental results can be explained and simulated in the Weiss mean field model. It isessentially a feedback model where the polarization evokes a field that in turn stimulates thepolarization. The model assumes that the electrostatic interaction between the dipoles leads to a
field αP proportional to the polarization of the system. The superposition of the external field andthe field due to the polarization yields the local field. At the dipole sites we find
Eloc = Ea + αP
(1)Assuming that the dipoles with dipole moment p and density n fluctuate thermally activated indouble well potentials, the transient polarization is described by a first-order differential equation (relaxation time),τdPp+ P = np tanh( Eloc )
dt
kT

(2)

Combining (1) and (2) with Ea=E0sin(wt) the dynamic hysteresis loop can be obtained. To get the
double hysteresis loop, the piezoeffect in the ferroelectric is introduced to the model. Due to thepiezoeffect the volume V of the sample changes with the polarization ( piezo coefficient),
V = V0 (1 + νP)(3)This causes the dipole density, the dipole moment and/or the coupling constant varying with thepolarization. Eqns. (1)-(3) can yield a second order or first order phase transition depending on thepiezo coefficients of the system. The simulation results show good coincidence with theexperiments.

ISAF-P3C-36 ____________________________________________________________________________________________________________________

Unexpected Domains Structure in BaTiO3 Single-Crystal
revealed by Confocal Raman Microscopy
F. Rubio-Marcos1, A. Del Campo1, P. Marchet2, and J. F. Fernández1.
1

Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC, Kelsen 5, 28049, Madrid,
Spain.
2
Laboratoire de Science des Procédés Céramiques et de Traitements de Surface, UMR 7315 CNRS,
Université de Limoges, Centre Européen de la Céramique, 12, rue Atlantis, 87068, Limoges Cedex,
France.
Email: jfernandez@icv.csic.es
Confocal Raman Microscopy, CRM, is used to in situ
resolve the domain structure in BaTiO3 single-crystals. Two
different BaTiO3 single crystals, BTO, are studied: (i) "c"plane or 001-plane, and (ii) "a"-plane or 100-plane.
These two orientation degrees provide different scenarios tostudy the domain structure in single crystal samples.
Obviously, the structure of the ferroelectric domain it isrelated to the crystallographic orientation. However, in bothorientations, the structure of "a-c" stripe domains has been
directly observed and resolved by CRM mapping. As arelevant result, unexpected needle-like "a-c"-domains bundle(represented by green color) with the reverse "a"- (and "c")subdomain orientation spontaneously nucleated, along thedomain wall which is formed by two single "a-c"-domains(in red and blue colors on Fig. 1, respectively). It
subsequently propagated forward until it reached the "a"domains (red) and alternating between "c"-domains (blue).
This unexpected configuration is clearly reflected in theformation of perpendicular domain boundaries in the depthscan of single-crystal BTO sample (Fig. 1c). The needlelike Fig. 86: Characterization in the a-plane of
domains appear as consequence of the surface stress in the the BTO single crystal through Confocal
BTO due the overlapping of "a" and "c" domain orientation. Raman Microscopy: (a) optical image. (b &The implications of the present findings introduce a fruitful
discussion to the 3D understanding of ferroelectric domain
structure and represent the key point to design new domainsthat allow engineering the piezoelectric response.

c) Raman color maps showing the
distribution of the different ferroelectricdomains: (b) in the a-plane of the planarsection and (c) of the depth scan or crosssection. (d) Raman spectrum of selected BTO
regions (represented by its color code)
indicating the characteristic Raman modes ofeach BTO ferroelectric domain .

ISAF-P3C-37 ____________________________________________________________________________________________________________________

Precise determination of piezoelectric d33-coefficients ofpiezoelectric thin films assisted by finite element modeling
Chris Stöckel1, Christian Kaufmann1, Robert Schulze1, Detlef Billep2, Thomas Gessner1,2
1Center for Microtechnologies (ZfM), Chemnitz University of Technology, Chemnitz, Germany
2Multi Device Integration, Fraunhofer (ENAS), Chemnitz, Germany
Email: chris.stoeckel@zfm.tu-chemnitz.de

For the design of piezoelectric microsystems, the determination of the piezoelectric coefficients isessential to predict the behavior and to optimize them. The paper presents an approach to determine
the d33–coefficient of piezoelectric thin films utilizing Finite Element (FE) simulations and Laser
Doppler Vibrometry (LDV). A detailed description of the interaction between the piezoelectric thinfilm and substrate is presented. The influence of the substrate properties and geometry is discussed.
For determining the d33 of piezoelectric thin films, equation (1) can be used [1,2]. It is shown thatfor thin films the influence of the piezoelectric transverse mode cannot be neglected. In equation (1)ξ is the deflection in consequence of an excitation with electrical voltage U and the ,andare the elastic coefficients of the piezoelectric material.
(1)
In [2] an infinitely stiff substrate is assumed, but an elastic constant of the substrate, e.g. silicon,
which is not infinite causes deviations in the determination of the d33 [3]. Therefore an investigationof this phenomenon and limitations of equation (1) were done using FE simulations.
For the verification of the FE simulation results PZT
thin films on silicon substrate were analyzed with
Laser Doppler Vibrometry. It can be noticed that there
is congruence of the measured and simulated
deflections of the substrate nearby the edge of thepiezoelectric material.
A high influence of electrode area and substrate
thickness has been determined in simulations andmeasurements, Fig. 1. The present results will be
discussed extensively in the article.
[1] P. Muralt: Piezoelectric thin films for MEMS. In: Integrated Ferroelectrics,
17 (1-4), pp. 297-307, 1997.
[2] K. Lefki and G. J. M. Dormans: Measurement of piezoelectric coefficients offerroelectric thin films. In: Journal of Applied Physics, 76(3), pp. 1764-1767,
1994.
[3] G. J. T. Leighton, et al.: Accurate measurement of the piezoelectric coefficientof thin films by eliminating the substrate bending effect using spatial scanninglaser vibrometry. In: Smart Materials and Structures 19(6), pp. 065011, 2010.

Fig. 87: Comparison of the measured
and simulated deflection showing theinteraction with the substrate.

ISAF-P3C-38 ____________________________________________________________________________________________________________________

Linear and Nonlinear Dielectric Properties of Ternary Solid
Solutions 0.4Na0.5Bi0.5TiO3-(0.6-x)SrTiO3-xPbTiO3
Šarūnas Svirskas1, Maksim Ivanov1, Šarūnas Bagdzevičius1, Jūras Banys1, Jan Dec2, Seweryn
Miga2, Marija Dunce3, Eriks Birks3, Maija Antonova3, Andris Sternbergs3
1

Vilnius University, Faculty of physics, Saulėtekio av. 9, III b., LT-10222 Vilnius, Lithuania
2
University of Silesia, Institute of Materials Science, Katowice, Poland
3
Institute of Solid State Physics, University of Latvia, Kengaraga street 8, LV-1063 Riga, Latvia
Email: sarunas.svirskas@ff.vu.lt
Sodium bismuth titanate (NBT) along with lead magnesium niobate (PMN) is one of the oldest
relaxor systems known. NBT attracts attention due to its promising electromechanical properties
and the absence of lead which is environmentally hazardous. Despite thorough studies which
already last for about 50 years there are still unanswered questions about this material. Recently, a
lot of interest in complex solid solutions containing NBT as primary material is shown270. Suchmaterials as strontium titanate, lead titnate or barium titanate were mixed with sodium bismuth
titanate in order to enhance dielectric, piezoelectric properties or to get knowledge how A-site ionsinfluence phase transitions of NBT.
Temperature dependences of the linear and the first order and second order nonlinear dielectricsusceptibilities give useful information on the formation of polar nano-regions. On the other hand,
broadband linear dielectric spectroscopy allows to evaluate the dynamics of polar nano regions (ordipolar entities in general). Distribution of relaxation times can be calculated from dielectric
spectra. On the other hand, nonlinear dielectric measurements help to identify the order of phasetransition precisely and the nonlinear scaling factor a3 shows the fundamental differences between
classical ferroelectrics and relaxors or dipolar glasses271.
In this work we present our measurements of 0.4NBT-(0.6-x)ST-xPT (x = 0, 0.05, 0.1, 0.15, 0.2).
The exchange of strontium with lead changes dielectric properties dramatically. The system in low
lead side of phase diagram exhibits relaxor-like properties and when the content of PT increases thephase transition from relaxor to ferroelectric state occurs.

270

Jung-Kun Lee et. al. J. Appl. Phys. 91, 4538 (2002)
Seweryn Miga, Jan Dec and Wolfgang Kleemann “Non-Linear Dielectric Response of Ferroelectrics, Relaxors andDipolar Glasses”, Ferroelectrics - Characterization and Modeling, ISBN: 978-953-307-455-9 (2011)271

ISAF-P3C-39 ____________________________________________________________________________________________________________________

Nano-domain engineering in ultrashort-period
ferroelectric superlattices
Jaichan Lee1, Taekjib Choi2, Hyungjung Shin3, Bae Ho Park4
1

School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU),
Suwon, Korea
2
Faculty/Institute of Nanotechnology and Advanced Materials Engineering, Sejong University,
Seoul, Korea
3
Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, Korea
Email: jclee@skku.edu
Ultrashort-period PbZrO3 (PZO)/PbTiO3 (PTO) ferroelectric/antiferroelectric superlattices areproposed for nano-domain engineering.1 The ultrashort-period PZO/PTO superlattices behaved likesingle ferroelectric metamaterials with monodomain-like excluding 90° domain boundary,irrespective of total thicknesses. Further, nanosized 180° domains, as small as ~12 nm, wereachieved by applying short pulse voltage. Such domain structures of superlattices result fromlowering the symmetry of supercell by specific atomic stacking in superlattices, contrary to domain
structures of ferroelectric thin films developed by the strain-induced ferroelectric instability, as
shown in Fig. 1. Domain size increases linearly with the pulse voltage, while domain size is linearly
dependent on logarithmic value of the pulse duration. Domain wall motion can be explained by anactivated process following Merz’s law. The electric field (E) dependence of the domain wall
velocity (v) satisfied v ~ exp (-δ/E), where the activation field (δ) was found to be ~ 2.7 MV/cm. It
is noted that domain wall motion with a relatively high activation field implies a strong stability of
domain. In practice, the domain pattern shows a long-term retention behavior up to over one month.

Figure 1. (a) Supercell of the PTO/PZO artificial superlattice with various stacking periods, and (b)schematic of local polarization switching in the PTO/PZO superlattice using a scanning probe tip indata storage media applications.

1. T. Choi, B.H. Park, H. Shin, and J. Lee, “Nano-domain engineering in ultra-short-period
ferroelectric superlattices”, Appl. Phys. Lett. 100, 222906, 2012.

ISAF-P3C-40 ____________________________________________________________________________________________________________________

Influence of spin-phonon coupling in SrMnO3 and CaMnO3 on
their dielectric properties and phonon spectra

V. Goian1, M. Savinov1, V. Skoromets, J. Hejtmánek1, V. Bovtun1, M. Kempa1, F. Borodavka1, P.
Vaněk1, D. Nuzhnyy1, A.A. Belik2, J.H. Lee3, K.M. Rabe3, S. Kamba1
1

Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
2
WPI-MANA, National Institute for Materials Science, Tsukuba, Ibaraki, Japan3
Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey, USA
Email: savinov@fzu.cz
Investigated SrMnO3 and CaMnO3 ceramics crystallize in perovskite cubic Pm3m andorthorhombic Pnma crystal structure, respectively and exhibit magnetic phase transition to
antiferromagnetic G-type phase near 230 K and 120 K, respectively. Although both materials areparaelectric down to liquid He temperatures, recent first principles calculations predicted that both
systems can become ferroelectric and even ferromagnetic under a biaxial strain.272,273 The strain
effect was not yet confirmed experimentally, but Sakai et al.274 expanded SrMnO3 lattice by Ba
doping and successfully induced ferroelectricity in Sr1-xBaxMnO3 (x  0.45) with Tc  400 K andcanted ferromagnetism with TN  200 K. Important fact is that in this case the strong ferroelectricity(PS = 13 C/cm2 ) is driven by displacement of magnetic Mn4+ cations and the magnetoelectric
coupling is therefore the largest yet attained.274
Infrared reflectivity spectra of SrMnO3 ceramics reveal 25 cm-1 stiffening of the lowest-frequency
phonon below Néel temperature. The temperature change of polar phonon frequency is
extraordinarily high and we explain it by the exceptionally strong spin-phonon coupling. The samephonon shift with temperature was obtained from the first principles calculations. Polar phonons
become Raman active below TN, although they are forbidden in the cubic crystal structure. It gives
evidence that the cubic symmetry is locally broken due to the strong magnetoelectric coupling.
Multiphonon and multimagnon scattering is also seen in Raman spectra. Microwave and THz
permittivity is strongly influenced by hopping electronic conductivity, which is caused by a small
non-stoichiometry of the sample. THz conductivity unusually increases on cooling, while the DC
conductivity markedly decreases. Thermoelectric measurements gave the room-temperature free
carriers concentration of ne = 3.16·1020 cm-3 and the sample composition was determined as
Sr2+Mn4+0.98Mn3+0.02O2-2.99.
Our radio-frequency dielectric, THz and infrared studies of CaMnO3 ceramics reveal metal
insulator phase transition at TN and splitting of some polar phonons below TN. Both effects give
evidence on the strong spin-phonon coupling, which reduces crystal symmetry in this material.

272

J.-H. Lee and K.M. Rabe, Epitaxial-strain-induced multiferroicity in SrMnO3 from first principles, Phys. Rev. Lett.
vol. 104, p. 207204, 2010.
273

S. Bhattacharjee, E. Bousquet, and P. Ghosez, Engineering multiferroism in CaMnO 3, Phys. Rev. Lett. vol. 102, p.
117602, 2009274

H. Sakai et al. Displacement-type ferroelectricity with off-center magnetic ions in perovskite Sr1-xBaxMnO3, Phys.
Rev. Lett. vol. 107, p. 137601, 2011

ISAF-P3C-41 ____________________________________________________________________________________________________________________The nature of the defect structure of solid solutions based on leadzirconate titanate (PZT) (by ESR and NMR method)

I.P.Bykov1, Yu.A. Zagorodniy2, L.P.Yurchenko1V. V.Trachevsky3,
V.Dimza4, K.Nejezchleb5, L.Jastrabik6 A.Dejneka61
Frantcevych Institute for Problems of Materials Science, National academy of Sciences of Ukraine,
Kiev, 03680,Ukraine
2
G.V. Kurdumov Institute for Metal Physics, National Academy of Sciences of Ukraine, Kiev
03680, Ukraine
3
Technical Centre, National Academy of Sciences of Ukraine, 04070 Kiev,Ukraine
4
Institute of Solid State Physics,University of Latvia, 226063Riga,Latvia
5
Noliac Ceramics s.r.o.Školní 86, Libřice, CZ-503 44, Czech Republic
6
Institute of Physics ASCR, v. v. i., 182 21 Prague, Czech Republic
The nature of intrinsic and impurity defects in lead zirconate titanate and lead (PZT, PLZT )ceramics of various compositions prepared by solution chemistry has been explored. Using electron
paramagnetic resonance (EPR) and nuclear magnetic resonans (NMR), several defects sites havebeen identified in the as-received materials, which include Fe3+–oxygen vacancy (V 0) complex andisolated Cu2+ ions. Both of these ions are incorporated into the lattice by replacing the Ti (Zr) ion. A
Fe3+–VO complex serves as a sensitive probe of the local crystalline field environment of theceramic.The symmetry of this defects is roughly correlated with its phase diagram as thecomposition PZT. The paramagnetic center Fe3+–VO expariences tetragonal,rhombic andortorombic symmetry is varied PZT and PLZT. Paramagnetic center of the Cu2+ is differend, it
appears as though the addition of Zr and not a change in phase, is largely responsible in determining
the local environment of this acceptor impurity. The Cu2+ EPR weakly reflect the Ti-O or Zr-O
bond covalency in the perovskite lattice.
Two different lead ion positions with tetragonal and orthorhombic local symmetry were revealed in
PZT and PLZT ceramics on the base of 207Pb NMR spectra measurements at room temperature. The
obtained data and their analysis on the base of the spectra shape calculations are in agreement
experiment. The comparison of observed spectra in PZT and PLZT with calculated spectra
allowing for resonance frequency chemical shift and spin-spin interaction show that thedisplacements of lead and oxygen ions are not random quantities in the investigated PZT and
PLZT ceramic samples.

ISAF-P3C-42 ____________________________________________________________________________________________________________________WEAK FERROMAGNETISM IN DYSPROSIUM SUBSTITUTED BISMUTH FERRITECERAMICS
V. Koval1, I. Skorvanek2, H. Yan3, L. Mitoseriu4 and M. Reece3
1Institute of Materials Research, Slovak Academy of Sciences, Kosice, Slovak Republic
Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovak Republic
3
Nanoforce Technology Ltd & Materials Department, Queen Mary University of London, UK
4
Faculty of Physics, "Al.I. Cuza" University, Iasi, Romania
2

E-mail: vkoval@imr.saske.sk
Dysprosium-substituted bismuth ferrite (Bi1-xDyxFeO3, x = 0, 0.1 and 0.2) polycrystalline samples
were prepared by a modified solid-state reaction method, adopting the SPS powder precursors
consolidation followed by the rapid sintering and quenching process. By optimizing the annealing
conditions, a bulk density value up to 96% of the theoretical density was achieved for the doped
ceramics. The effect of the partial replacement of smaller Dy3+ ions for bigger Bi3+ ions on the
crystal structure, morphology, dielectric and magnetic properties was investigated. Roomtemperature X-ray diffraction investigations revealed the structural transformation of the initiallyrhombohedral R3c phase (x = 0) into a mixture of the R3c and Pnma phases with a final phase ratio
of about 1:3 for the x = 0.2 compound (Figure 1). It was found that the substitution inhibits thegrain growth and eliminates the appearance of secondary phases. t average grain size decreased
almost by one order of magnitude to  1.5 m as the concentration of dysprosium increased from 0
to 20%. A strong dielectric dispersion and anomalous dielectric behavior at elevated temperatures
were suggested to result from the interfacial polarization and hoping conduction mechanism ofoxygen vacancies. Magnetization measurements in a wide temperature and field range showed thatthe introduction of magnetic Dy3+ ions results in a weakly ferromagnetic state at room temperature,and the spontaneous magnetization can be further enhanced by decreasing the temperature down to
5 K. At room temperature, the maximum remanent magnetization (Mr = 0.34 emu/g) was achieved
for the Bi0.8Dy0.2FeO3 samples (Figure 2).

Figure 1. Refined XRD pattern of
Bi0.8Dy0.2FeO3 ceramics

Figure 2. M-H loops for Bi0.8Dy0.2FeO3
ceramics

ISAF-P3C-43 ____________________________________________________________________________________________________________________

Structure, dielectric, and piezoelectric properties of (0.95-x)
BiFeO3-x PbTiO3-0.05 Pb(Zn1/3Nb2/3)O3 ternary high Curie
temperature piezoelectric ceramics
Jiajia Jiang1, Jianguo Chen1, Jinrong Cheng1
1Electronic Information Material Department, Material Institute, Shanghai, China

Email: jrcheng@staff.shu.edu.cn
A series of solid solutions (0.95-x) BiFeO3-x PbTiO3-0.05 Pb(Zn1/3Nb2/3)O3 (BF-PT-PZN) (x=0.30, 0.31, 0.33, 0.35, 0.37, 0.40) have been fabricated by solid state reaction method. X-ray
diffraction analysis revealed that phase transition from rhombohedral to tetragonal was observed at
PT content of 0.35. Values of the dielectric constant εr, dielectric loss tangent tanθ, Curie
temperature Tc and piezoelectric constant d33 for the composition x=0.35 were of 250, 0.02, 550 °C
and 70 C/N, respectively. Temperature-dependent piezoelectric constant and electromechanicalcoupling coefficient were stable from room temperature up to 450 oC, about 300 oC higher than thatof conventional Pb(Zr,Ti)O3 (PZT) piezoelectric ceramics. All these results together with the goodthermal stabilities made the BF-PT-PZN ceramics promising candidates for high temperature
piezoelectric applications.

Key words: High Curie Temperature, piezoelectric properties, ternary system

ISAF-P3C-44 ____________________________________________________________________________________________________________________

Search for Polar LiNbO3-Type Compounds
Alexei A. Belik1, Takao Furubayashi2, Hitoshi Yusa2, Eiji Takayama-Muromachi2
1International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute forMaterials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
2
NIMS, Tsukuba, Ibaraki 305-0047, Japan
Email: Alexei.Belik@nims.go.jp

ABO3 compounds crystallize in a number of structure types, e.g., perovskite, LiNbO3, hexagonal
LuMnO3-type, hexagonal BaMnO3-type, pyroxene, corundum, ilmenite (ordered corundum), rareearth sesquioxide structures (A, B, and C (bixbyite)), PbReO3, KSbO3, AlFeO3, CaIrO3, and others.
The LiNbO3 structure in principle can be described as a highly distorted perovskite structure, towhich it can be related by a displacive transformation. The LiNbO3 structure is polar (space groupR3c). Therefore, LiNbO3-type compounds should exhibit ferroelectric and piezoelectric properties
footnotes275.
Most of the ABO3 compounds crystallize in the perovskite-type structure. However, when the sizeof the A-type compounds is decreased the LiNbO3-type structure can be stabilized.
In this work, we investigated ABO3 compounds with A = Sc and In2,3. We will discuss a new classof multiferroic materials: In-based perovskites. We show that In1xMxMO3 with x = 0.1120.176
and M = Fe0.5Mn0.5 has the LiNbO3-type structure(Fig. 1) and high Curie temperature; In1xMxMO3
is a canted antiferromagnet with the Néel
temperature close to RT2. In1xMxMO3 presents a(Mn,Fe)O
new class of perovskite materials (with In3+ in the
A site of a perovskite ABO3) that is almost
completely unexplored. This class of materials is
unique because (1) long-range magnetic ordering
InO6
survives near room temperature (RT) despite ofsignificant disordering in the A and B sites, (2)the same transition metals are located in both A
and B sites, and (3) a polar distortion is realized
without presence of ions with the lone electron
pair. Our results give a significant contribution to Fig. 88: Crystal Structure of In M MO with x =1x x
3
the development of RT multiferroics and open 0.1120.176 and M = Fe Mn .
0.5
0.5
wide possibilities for thin-film research andfuture improvement of In-based perovskites. Our
results also show new ways for the preparation of perovskite-type materials.
6275

A. A. Belik, T. Furubayashi, H. Yusa, E. Takayama-Muromachi, J. Am. Chem. Soc. 133, 9405 (2011).

2

A. A. Belik, T. Furubayashi, Y. Matsushita, M. Tanaka, S. Hishita, E. Takayama-Muromachi, Angew. Chem. Int. Ed.
48, 6117 (2009).
3

A. A. Belik, Y. Matsushita, M. Tanaka, E. Takayama-Muromachi, Angew. Chem. Int. Ed. 49, 7723 (2010).

ISAF-P3C-45 ____________________________________________________________________________________________________________________

Dielectric properties of modified BiFeO3 ceramics
Kachaporn Sanjoom1,3, Duangpon Laksawat1, Kamonpan Pengpat1,2, Sukum Eitssayeam1,2 andGobwute Rujijanagul1,2,3,*
1

Department of Physics and Materials science, Faculty of Science, Chiang Mai University,
Chiang Mai, 50200, Thailand
2
Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai,
50200, Thailand
3
Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Sri Ayutthaya
Road, Bangkok, 10400, Thailand
Email: rujijanagul@yahoo.com

The modified BiFeO3 (BFO) ceramics (BFO doped with Sb and Dy) were prepared by a solid-state
reaction method. Excess Bi2O3 (3 wt%) was introduced prior to powder calcination to compensate
for any Bi2O3 that may have been lost from the samples due to volatilization during heat treatments.
X-ray diffraction analysis revealed that pure phase perovskite was observed for the samples
calcined at a low heating rate. Dielectric behavior of undoped ceramic exhibited high dielectric
constant over a wide temperature region. However, the doping shifted this region to a higher
temperature. The doping affected the peak of dielectric loss of the samples. Activation energy ofdielectric relaxation also shifted with increasing the additive concentration. In addition, complex
impedance analysis was applied to determine the behavior of grain boundary and grain after doping.

Acknowledgements This work was supported by National Research University (NRU), Office ofHigher Education Commission (OHEC), Thailand center of excellence in Physics (Thep) andFaculty of Science and Graduate School Chiang Mai University.

ISAF-P3C-46 ____________________________________________________________________________________________________________________

Electrical properties of PbLaZrTiOx capacitorswith conductive oxide buffer layer on Pt electrodes
Takeyasu Saito, Yoko Takada, Toru Tsuji, Naoki Okamoto, Kazuo Kondo, Takeshi Yoshimuraa,
Norifumi Fujimuraa, Koji Higuchib, Akira Kitajimab, and Akihiro OshimabaDept. of Chem. Eng., Osaka Prefecture University, Sakai, Osaka 599-8531, JAPAN
Dept. of Phys. Electro., Osaka Prefecture University, Sakai, Osaka 599-8531, JAPANb
Inst. of Sci. and Ind. Res., Osaka University, Ibaraki, Osaka 567-0047, JAPAN
Email: tsaito@chemeng.osakafu-u.ac.jp

Ferroelectric Random Access Memory (FeRAM) has attracted much attention and it is believed to be
next generation non-volatile memory for its high operation (read/write) speed and low power
consumption1). To achieve higher density integration, ferroelectric capacitors requires higher switching
charge and better fatigue and imprint properties. It was reported that the introduction of a buffer layer is
one of effective methods to improve fatigue characteristics of ferroelectric thin films2). A buffer layer
was also used to control the orientation of ferroelectric thin films3). In this study, we used conductive
Al-doped ZnO (AZO) and Sn doped In2O3 (ITO) as buffer layer on Pt bottom electrodes.
The substrates were highly (111)-oriented sputtered Pt as lower electrodes.
PLZT(Pb:La:Zr:Ti=113:3:30:70) films (500 nm) were prepared by the sol-gel method. The films were
deposited on Pt substrate by spin coating, at 3000 rpm for 20 s. Then, the gel-films were dried at 200℃
for 2 min in order to eliminate the solvent, and pyrolyzed at 300℃ for 10 min, in air for organic
components removal. The films were prepared by repeating (3 times) the deposition and pyrolysis
cycle. The prepared thickness was 500 nm. The coated films were finally calcined in air at 750℃, 10min, in air for achieving crystallization. AZO buffer layers and top electrodes were deposited by PLD(Pulsed Laser Deposition). This deposition was performed with a metal through mask having 50 um ~500 um diameter. The composition of AZO and ITO targets were ZnO:Al2O3=98.5:1.5 wt.% andIn2O3:SnO2=95.0:5.0 wt.%, respectively.
Fig. 1 shows the polarization values of PLZT capacitors with
AZO top electrodes and with or without AZO buffer layer from 10
nm ~ 120 nm. Polarization value of PLZT capacitors with 10 nm
buffer layer and without buffer layer were 21.6 C/cm2 and 18.2
C/cm2, respectively at 15 V. The polarization ratio of PLZT
capacitors with 10 nm buffer layer and without buffer layer after107
10 V, 100 μs width and 1 ms interval cycles were 0.60 and 0.39,
respectively. PLZT capacitors with AZO buffer layer were also
confirmed to be promising in terms of hydrogen endurance.
References
1) M.M. Zhang et al, Solid-State Electronics, Vol. 53, p. 473(2009).

Fig. 1 Hysteresis loops of PLZT
capacitors with or without buffer2) H. Peng et al., Progress in Natural Science: Materials International, Vol. 22, p. 219 (2012)
layer.
3) X.S. Wang et al, Scripta Materialia, Vol. 46, p. 783 (2002)

ISAF-P3C-47 ____________________________________________________________________________________________________________________

Polarization Reversal in Crystals of Congruent Lithium
Tantalate at Elevated Temperatures
Chezganov Dmitry1, Shur Vladimir1,2, Baturin Ivan1,2, Akhmatkhanov Andrey1,21Ferroelectric laboratory, Ural Federal University, Ekaterinburg, Russia
2
Labfer Ltd., Ekaterinburg, Russia
Email: dmit.chezganov@gmail.com

The polarization reversal and domain structure evolution under application of linear increasing fieldhas been studied in single crystalline congruent lithium tantalate (LiTaO3) in range from room
temperature to 250OC. The fitting of the switching current data by modification of KolmogorovAvrami formula for switching in linear increasing field has been used for characterization
polarization reversal process276,277. The static domain patterns revealed by selective chemical
etching have been visualized by optical microscopy at both polar surfaces.
The analysis of the switching current data obtained at low temperatures (below 200 OC) allowed us
to separate the polarization reversal process in three stages. The first stage starting at low field was
fitted by β (2D) model corresponding to growth of domains existing in the initial state. The
beginning of appearance of new domains at the second stage allowed us to fit the current in terms of(β+α) (2D) model. The termination of nucleation at the final stage leads to return to domain kinetics
according to β (2D) process.
The current shape changes essentially for the temperatures above 200OC. In this case the role of theinitial domain growth is negligible. Thus from the very beginning the switching current has been
fitted successively in terms of α (2D) model. The final stage of the switching process has been fitted
by exponential decay with additional switching current component corresponding to bulk
conductivity.
The proposed fitting allowed us to extract the value of the threshold field at which the nucleation of
new domains begins. The threshold field two times decrease was revealed in the studied
temperature range. The temperature dependence of the domain kinetics and shape of isolated
domains at both polar surfaces was observed. The shape of isolated domains changes fromtriangular to circular at temperatures above 200OC. Moreover it was shown that the growth of nonthrough domains observed at low temperatures changed by formation of through truncated conicaldomains at elevated.
The observed experimental facts have been attributed to effective bulk screening due to increase of
the bulk conductivity at elevated temperatures.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has
been used. The research was made possible in part by RFBR (Grants 13-02-01391-а, 11-02-91066CNRS-а), by Ministry of Education and Science (Сontract 14.513.12.0006), by OPTEC LLC.
276

V. Ya. Shur, E. L. Rumyantsev, S. D. Makarov, Kinetics of phase transformations in real finite systems: Application
to switching in ferroelectrics. J. Appl. Phys., vol. 84, p. 445–451, 1998.
277

V. Ya. Shur, E. L. Rumyantsev, S. D. Makarov, A. L. Subbotin, and V. V. Volegov, Transient current duringswitching in increasing electric field as a basis for a new testing method. Integr. Ferroelectr., vol. 10, p. 223–230, 1995.

ISAF-P3C-48 ____________________________________________________________________________________________________________________ELECTRICAL AND MAGNETIC PROPERTIES OF A NEW AURIVILLIUS PHASE
Bi14ThFe4Ti8O45
a

V. G. Vlasenko , V.A. Shuvaevaa, S.Zubkova, S. LevchenkovbaSouthern Federal University, Research Institute of Physics, Stachki Ave. 194, Rostov-on-Don,
344090, RussiabSouthern Federal University, Department of Chemistry, Zorge str. 7, Rostov-on-Don, 344090,
RussiaRecently Aurivillius phases, containing magnetic cations, such as Bi5Ti3FeO15, have drawn
special attention as they have potential to display both ferroelectric and ferromagnetic properties
simultaneously
A new layered perovskite-like oxide Bi14ThFe4Ti8O45, has been prepared, and thetemperature dependence of the dielectric and magnetic properties of the material has been
investigated. The composition and structure of the material is close to that of multiferroic material
Bi5Ti3FeO15 but it has a higher content of magnetoactive Fe3+ due to partial substitution of Bi by Th
in B perovskite positions. The dielectric properties of Bi14ThFe4Ti8O45 were studied in atemperature range from 295 K to 1200 K at fixed frequencies of 100, 200, 500 and 1000 kHz. The
temperature dependence of the dielectric constant ε/ε0(Т) reveal a broad peak at about 970 K, which
is typical of a ferroelectric material with a high conductivity, undergoing a diffuse phase transition.
The magnetic susceptibility of the sample has been measured by the Faraday method in thetemperature range from 77.4 K to 300 K. The values of magnetic susceptibility of the sample at 295
and 77 K were found to be 5.88·10–6 и 14.16·10–6cm3/g respectively and the corresponding
magnetic moments per formula unit were calculated to be 7.91 и 6.28 mB. The temperaturedependence of the 1/χg is typical for paramagnetic compounds with short range antiferromagnetic
exchange. The extrapolation of the part of the curve, measured at temperatures above 150 K, to the
low temperature region yields a Weiss constant of -200 K, which is lower than that of Bi5Ti3FeO15.
This shows that higher Fe concentration results in enhancing of antiferromagnetic coupling.

ISAF-P3C-49 ____________________________________________________________________________________________________________________A New Criterion regarding the Flack parameter
J. Fábry1, M. Dušek2
1

2

Department of Dielectrics, Institute of Physics AS CR, Prague, Czech Republic
Department of Structure Analysis, Institute of Physics AS CR, Prague, Czech Republic
Email: fabry@fzu.cz

Existence of ferroelectric crystal structures is limited to the point groups 1, 2, 3, 4, 6, m, 2mm, 3m,
4mm, 6mm. All these point groups and the respective space groups are non-centrosymmetric. In
practice, non-centrosymmetric crystals structures, determined by single crystal X-ray diffraction,
are nowadays refined with inclusion of the Flack parameter278. Flack and his collaborators
published a series of articles (e.g.279) in which they investigated behaviour if this parameter andassessment of its reliability in dependence of various conditions such as prominence of the resonant
scattering, presence of pseudocentrosymmetric substructure in the structure and quality of themeasurement. Here, another criterion for the reliability of the Flack parameter is suggested. It takes
into account the contribution of the resonant scattering to intensity of each diffraction hkl andcompares this contribution to the standard uncertainty of the observed intensity. The advantage ofthese criteria follows from the fact they are independent of the measurement of the Bijvoet pairs.

278
279

H. D. Flack, Acta Cryst. A39, 876-881 (1983).
H. D. Flack & G. Bernardinelli, Acta Cryst. A64, 484-493 (2008).

ISAF-P3C-50 ____________________________________________________________________________________________________________________

Optical and electrical properties of (Ba1−xCax)(ZryTi1−y)O3 thin films
obtained by pulsed laser deposition assisted by radio-frequency
discharge.
N. D. Scarisoreanu1, F. Craciun2, A. Andrei1, V. Ion1 , R. Birjega1, L.Nedelcu3, M.G. Banciu 3 and
M. Dinescu1.
1

2

NILPRP, P.O. Box MG-16, RO-77125, Bucharest, Romania
CNR-Istituto dei Sistemi Complessi, Area della Ricerca Roma-Tor Vergata, Via del Fosso delCavaliere 100, I-00133, Rome, Italy
3
NIMP-National Institute of Materials Physics, 077125 Bucharest-Magurele, Romania
Email: snae@nipne.ro

The dielectric and piezoelectric characteristics of (Ba1−xCax)(ZryTi1−y)O3 ceramic systemhave been reported for bulk form, but its properties in form of thin films are still unexplored. We
report on the growth of lead-free perovskite (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 thin films using pulsed laser
deposition assisted by radio-frequency discharge (RF-PLD) for MEMS applications.
A parametric study on the influence of substrate temperature and gas pressure on the
dielectric and piezoelectric properties of thin layer was carried out.
Dielectric function of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 was determined in low range of frequencies(1KHz-100 MHz) and in the optical domain (2501700 nm) using dielectric spectroscopy and
70
180
 Exp
ellipsometry techniques. Topography of surface
 Mod
65
was evaluates by atomic force microscopy (AFM)
160
60
techniques, while the piezoelectric response was140
measured by PFM technique. In the measured
55
frequency domain, the films exhibit moderate
50
120
dielectric constant (≈ 450) and relatively low
45100
dielectric losses (≈ 1.5 %). In order to extract the40
dielectric function (refractive indices and
80
 Exp
35
extinction coefficients, the ellipsometric analyses
 Mod
30
60
were carried out. The final values of refractive
600
800
1000
1200
(nm)
indices, absorption and optical band-gap were
calculated with Lorentz oscillator model.
Fig. 89: Ellipsometry spectrum for BCTZ thin film growth
0



0

0

0
0

on platinized silicon (i.a. 700). The black dots represent theexperimental data, while the open circles result from the fitting
procedure using a Cauchy dispersion formula.

ISAF-P3C-51 ____________________________________________________________________________________________________________________

Ultrasonic Investigation of Phase Transition Temperature
Hysteresis in Ba2Nd(1-x)Pr(x)FeNb4O15 solid solutions
Martynas Kinka1, Vytautas Samulionis1, Michael Josse2, Dainius Gabrielaitis1, Robertas Grigalaitis1
and Mario Maglione2
1

2

Faculty of Physics, Vilnius University, Vilnius, Lithuania
ICIMCB-CNRS, Universite de Bordeaux, Bordeaux, France
Email: martynas.kinka@delfi.lt

Ba2Nd(1-x)Pr(x)FeNb4O15 solid solutions under investigation here belong to the Tetragonal Tungsten
Bronze (TTB) structural family, which is one of the largest oxygen octahedral ferroelectric families
next to the ferroelectric perovskites. Three types of open channels that develop within TTB
structure allows solid state chemists to perform a wide range of substitutions triggering various
ferroic properties. Recently, dielectric investigations of Ba2Nd(1-x)Pr(x)FeNb4O15 ceramics suggested
the continuous transformation from the ferroelectric behavior of Ba2NdFeNb4O15 to the pure relaxor
response of Ba2PrFeNb4O15 with increasing x280. For intermediate x values, coexisting ferroelectrictransition and relaxor dielectric signatures were observed, corresponding to two different
phenomena in the framework of these materials. Ferroelectric transition is accompanied by a 50 K
wide cooling–heating hysteresis, which origin
is still under discussion.
In order to define the phase diagram (Fig. 1)
more precisely we have decided to investigate
elastic properties of these materials by
ultrasonic spectroscopy, because this nondestructive technique is very useful for
identification of phase transitions. In this way,
we have studied the temperature dependence ofthe longitudinal ultrasonic velocity andultrasonicattenuation
in
Ba2Nd(1solid solution family. Inx)Pr(x)FeNb4O15
addition our ultrasonic method allowed us toinvestigate piezoelectric sensitivity of these Fig. 90: Ba2Nd(1-x)Pr(x)FeNb4O15 phase diagram, where
TTB samples. The experiments showed small □, ○ – ferroelectric phase transition temperatures on
anomalies of ultrasonic velocity and cooling and heating determined from dielectric data;attenuation, which depend on the thermal ■, ● - ferroelectric phase transition temperatures on
cooling and heating determined from ultrasonichistory of samples. The piezoelectric sensitivity measurements; ▲ – temperatures of ultrasonicwhich was observed in low temperature phase anomalies probably caused by relaxor state; ◊ confirmed the existence of the polar phase e.g. calculated TVF values.
theferroelectric
phasetransition
inBa2NdFeNb4O15 material and their solid solutions with Ba2PrFeNb4O15.

280

M. Kinka, “Coexistence of Ferroelectric and Relaxor States in Ba 2PrxNd1−xFeNb4O15 Ceramics”, IEEE Trans.
Ultrason., Ferroelectr., Freq. Control, vol. 59, p. 1879-1882, 2012

ISAF-P3C-52 ____________________________________________________________________________________________________________________

Pyroelectric and electrocaloric properties of
PZT- and BaTiO3-based ceramics

Hiroshi Maiwa1
1

Department of Materials and Human Environmental Sciences, Shonan Institute of Technology,
Fujisawa, Japan
Email: maiwa@mate.shonan-it.ac.jp

Thermal energy harvesting using non-linear pyroelectric effects in PZT with different Tc, PLZT,
Ba(Zr0.2Ti0.8)O3 and (Ba0.8Sr0.2)TiO3 ceramics, and PMN-PT crystals were investigated.
Commercial bulk Ba(Zr,Ti)O3 (BZT), (Ba,Sr)TiO3 (BST) and PLZT(7/65/35) powders (Hayashi
Chemical) were used as starting materials. The powders were fired at 1350°C for Ba(Zr,Ti)O3,
1400°C for (Ba,Sr)TiO3, 1225°C for PLZT ceramics. 0.2mol%Mn-doped BZT (BZT-Mn) wereprepared using the same procedure.
To characterize the non-linear pyroelectric response,
polarizations of the samples at various temperatures were measured using a combination of aprogrammable signal generator and a charge-amplifier. The samples were cut into 3-5 mm squares,
and the temperatures of the samples were changed by immersing them in a heated oil bath. PLZT
ceramics (3x3x4mm) rod were used for the ECE measurement. The temperatures were measured
using radiation temperature sensor.
Measurements of the polarization in ceramics were
performed using a charge-amplifier circuit. An
alternating electric field of 0.1 Hz was used inthese measurements. The relationship between
high temperature and stored energies is show in
Fig. 5. Generally, stored energies increased withtemperature, due to the expanding of thedifference of the polarization at room temperatureand high temperature. PLZT ceramics with Tc of140°C exhibited large energy generation of 54.8
J/L/cycle with temperature variations from 30°C to
200°C and field variations from 0 to 20kV/cm.
Ba(Zr0.2Ti0.8)O3 ceramics with Tc of 40°C
exhibited energy generation of 58.6 J/L/cycle withtemperature variations from 30°C to 125°C and Fig. 91: Relationship between high temperature andfield variations from 0 to 20kV/cm.
stored energies for Ba(Zr,Ti)O3, Ba(Zr,Ti)O3-Mn,(Ba,Sr)TiO , and PLZT(7/65/35) ceramics.

3
The electrocaloric temperature changes ∆T due toapplied ∆E were measured.
PLZT(7/65/35)
ceramics exhibited ∆T of 0.2K at room temperature under a bipolar switching field of 20kV/cm.

This study was supported in part by a grant in aid (C, No.22560671) and GRENE (Green networkof excellence) project from the ministry of education, culture, sports, science, and technology,
Japan.

ISAF-P3C-53 ____________________________________________________________________________________________________________________

Temperature Dependence of Electric Field Induced Changes inRaman Spectrum of Lithium Niobate Single Crystals
Zelenovskiy Pavel1, Shur Vladimir1, Mingaliev Eugene1, Bourson Patrice2, Fontana Marc2
1

2

Ferroelectric Laboratory, Ural Federal University, Ekaterinburg, Russia
Laboratory of optical and photonic materials and systems, University of Lorraine, Metz, France
Email: zelenovskiy@labfer.usu.ru

The temperature dependence of Raman spectrum changes induced by residual depolarization fieldin the vicinity of the domain walls has been studied in periodically poled lithium niobate single
crystals. It was demonstrated that the changes of measured integrated intensity and frequency shiftof specified Raman lines disappeared at temperatures above 120°C.
It has been shown experimentally that the parameters of specified Raman lines, being very sensitive
to lattice distortion, change remarkably in the vicinity of the domain walls produced at room
temperature in lithium niobate (LiNbO3, LN) single crystals281. This effect is used for visualizationof the micro- and nanodomain structures in LN both at the surface and in the bulk using Raman
confocal microscopy282. While the effect is absent for domain structure produced at elevatedtemperatures. The changes of the Raman spectrum have been attributed to distortion of the crystal
lattice induced by the residual depolarization field existing in the vicinity of the domain walls near
the crystal surface1.
The changes of integrated intensity and frequency of E(TO8) and A1(LO4) Raman lines were
measured in Z ( xx) Z configuration in the vicinity of neutral domain walls LN surface at different
steady-stated temperatures ranged from 25 to 120°C. The mapping of Raman spectra across thedomain walls has been done at constant temperature.
It has been revealed that the absolute values of the integrated intensity changes gradually decreased
with temperature increasing and disappeared at 120°C. Frequency shift of E(TO8) line possesses
strong variations while the shift of A1(LO4) line remains approximately constant during the wholetemperature range. At temperature 120°C frequency shift rapidly goes to zero for both spectral
lines.
The additional experimental measurement of the temperature dependence of the pyroelectric field
during heating with the constant rate about 7°C/min demonstrates the field maximum just at 120°C.
This fact has been attributed to increase of the bulk conductivity leading to more effective screeningof the depolarization field and decreasing of pyroelectric field283. It is clear that effective bulk
screening at elevated temperature must diminish the residual depolarization field in the vicinity ofthe domain wall thus leading to disappearance of the changes of Raman spectrum.
The research was made possible in part by RFBR (Grants 13-02-01391-а, 12-02-31377-mol-a, 1102-91066-CNRS-а); by Ministry of Education and Science (Contracts 14.513.12.0006 and
281
282
283

P.S. Zelenovskiy, V.Y. Shur, P. Bourson, M.D. Fontana, D.K. Kuznetsov, and E.A. Mingaliev, Ferroelectrics 398, 34 (2010).
P.S. Zelenovskiy, M.D. Fontana, V.Ya. Shur, P. Bourson, and D.K. Kuznetsov, Appl. Phys. A 99, 741 (2010).
V.Ya. Shur, D.K. Kuznetsov, E A. Mingaliev et al., Appl. Phys. Lett. 99, 082901 (2011).

16.740.11.0585), by OPTEC LLC and in terms of Ural Federal University development programwith the financial support of young scientists.

ISAF-P3C-54 ____________________________________________________________________________________________________________________

Retention of Thin Ferroelectric VDF-TrFE Copolymer Films
Evaluated from Dielectric Non-Linearities
Danny von Nordheim1, Sebastian Koch1, Soichiro Okamura2, Bernd Ploss1
1

2

Department of SciTec, University of Applied Sciences Jena, Jena, Germany
Department of Applied Physics, Tokyo University of Science, Shinjuku, Tokyo 162-8601,

Japan

Email: danny.von.nordheim@fh-jena.de
Polarisation retention of a ferroelectric is an important feature for most of its applications,especially for memories but also for pyroelectrics or piezoelectrics. On the other hand, a reduction
or loss of remanent polarisation might be favourable when the ferroelectric is used as the dielectric
in a capacitor to store energy.
In the common procedure to investigate retention the ferroelectric sample is first polarised by theapplication of an appropriate voltage pulse. After a specified time a further voltage pulse is applied
while the charge response is recorded. The limitation of this technique is that the sample ispolarised again by the second ‘read’ pulse and a continuous recording of polarization loss is notpossible. Therefore we propose an alternative procedure which is based on the continuous
measurement of the small signal linear and second order non-linear dielectric permittivity as afunction of time after the sample has been polarized by a ‘write’ pulse. As the polarisation of theferroelectric is not influenced by the small signal measurement, this non-destructive method gives
an accurate measure of the temporal development of polarisation.
Thin VDF-TrFE copolymer films of molar ratio 70/30 and thickness below 200 nm have been
deposited by spin coating on a glass substrate covered with aluminium electrodes. After annealing
at a temperature appropriate for films with this thickness and deposition of the top electrodes, thesample has been poled with a series of positive triangular pulses. Directly after the last poling pulse
a small sinusoidal voltage has been applied to thesample while the current response has beenrecorded and analysed in terms of first andsecond order permittivities. The quotient() is proportional to the remanentpolarisation. At 30 °C we observed an initial
decrease of polarisation with a time constant of
about 1 hour which finally settled at about 80 per
cent of the initial value. This reduction afterpoling is essentially attributed to therearrangement of charges injected into theferroelectric film by the poling pulses.
The same non-destructive method can be used toread out the polarisation state of a ferroelectric Fig. 92: Polarisation versus time for a 90 nm thinmemory cell making a rewrite of the initial P(VDF-TrFE) sample at 30 °C.
polarisation dispensable. Thus, the readout speed
and the cell’s lifetime could be improved.

ISAF-P3C-55 ____________________________________________________________________________________________________________________

Composition and Morphology Effects on the Thermal
Conductivity of PZT Thin Films
Jon F. Ihlefeld,1 Brian M. Foley,2 John C. Duda,2 Harlan Brown-Shaklee,1 Douglas Medlin,3 Bryan
D. Huey,4 Bonnie B. McKenzie,1 Brady J. Gibbons5 and Patrick E. Hopkins2
1

Sandia National Laboratories, Albuquerque, New Mexico/USA
Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville,
Virginia/USA
3
Sandia National Laboratories, Livermore, California/USA
4
Institute of Materials Science, University of Connecticut, Storrs, Connecticut/USA
5
Materials Science, School of Mechanical, Industrial, and Manufacturing Engineering, Corvallis,
Oregon/USA
2

Email: jihlefe@sandia.gov
In this presentation we explore the effects of composition, phase, and morphology on the thermal
conductivity of lead zirconate titanate thin films. Epitaxial and polycrystalline films withcompositions ranging from PbZr0..2Ti0.8O3 to PbZr0..8Ti0.2O3 have been prepared by chemicalsolution deposition on (001)-oriented SrTiO3 and Pt/ZnO/SiO2/Si substrates.
Thermalconductivities were measured using time-domain thermoreflectance at room temperature. For
single-crystalline films, the composition dependent thermal conductivity trend will be shown to beconsistent with that expected for alloy scattering from the mixed B-site. For polycrystalline films, itwill be shown that grain boundary scattering dominates the measured thermal conductivities anddecreases the composition dependence. For specific compositions in both epitaxial andpolycrystalline films, however, a decreased thermal conductivity is observed that is consistent with
scattering from finer-scale features. These results will be discussed in the context of phonon
scattering from domain walls. This presentation represents one of the first studies of thecomposition and morphology dependence of thermal conductivity in a ferroelectric thin film.
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia
Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Departmentof Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

ISAF-P3C-56 ____________________________________________________________________________________________________________________

Comparable Measurements and Modeling of Piezoelectric Thin
Films for MEMS application
Thorsten Schmitz-Kempen1, Stephan Tiedke1, Peter Mardilovich2, Subramanian Sivaramakrishnan2,
Thomas Lisec3, Fabian Stoppel3
1aixACCT Systems GmbH, Aachen, Germany
2
Hewlett-Packard, Corvallis, USA
3
Fraunhofer Institute for Silicon Technology, Itzehoe, Germany
Email: schmitz@aixacct.com
Accurate and reliable measurements of piezoelectric coefficients on thin films are required toperform thin film process development and compare different manufacturing techniques and quality
especially in MEMS applications.
State of the art measurements are performed by double-beam laser interferometry since many years,
however the variety of parameter ranges and test conditions make it difficult to compare
measurement results. Films on a substrate exhibit effective piezoelectric coefficients due tosubstrate clamping and the coefficient also depends on feature size and substrate thickness. Thiswas shown by FEM simulations for the case of d33,f measurements by DBLI (K. Prume et al, Proc.
IEEE ISAF 2004) and latest simulation and measurement results show that a considerable reductionof the measured d33,f was obtained for small electrodes and an increase for large electrodes. The
measured d33,f value at large electrodes is even larger than the true d33,f of the film and for smallfeature sizes it is lower. A feature size chosen equivalent to the substrate thickness exhibits the mostexact number for the effective coefficient d33,f (S. Sivaramakrishnan et al, presentation on 3rd
PiezoMEMS Workshop 2013).
Furthermore nonlinearity and hysteresis of ferroelectric films requires the definition of
measurement parameters to obtain comparable procedures regarding hysteresis, poling conditions,and other property nonlinearities, voltage and frequency dependency of coefficients, and large andsmall signal responses. For easier comparison of films a large signal coefficient (d33,ls) is introduced
as the average slope of a displacement vs. voltage measurement over the full operating voltage
range. For thin film measurements it reflects the potential displacement in typical actuatorapplications in comparison to small-signal coefficients and allows better comparison of materials
for actuation.

ISAF-P3C-57 ____________________________________________________________________________________________________________________

Investigation of the dielectric, piezoelectric and elastic
properties of BaTiO3 by means the thermal noise method
I. Shnaidshtein1, P. Bednyakov2, B. Strukov1
1

2

Lomonosov Moscow State University, Moscow, Russia
École Polytechnique Fédérale de Lausanne, Lausanne, Suisse
Email: shnaidshtein@physics.msu.ru

Crystals of barium titanate BaTiO3 (BT) belong to classical model ferroelectrics which have been
extensively investigated by various methods since the discovery of their ferroelectric properties.
However the role of the fluctuation effects at the ferroelectric phase transition in BT crystals is so
far not clear284. This is due both to the fact that the ferroelectric phase transition in BT is a phasetransition of the first order and with the difficulty to differ the behavior related with the fluctuations
and other similar factors such as defects or the experiment conditions.
The thermal noise method allows to controlling the experimental conditions due to the absence ofthe measuring voltage. Moreover, that in BT crystals noise voltage level is high and as it was shown
earlier by Brophy and Webb285 it can be changed by changing the thermal conditions of theexperiment. By this way we can separate the different contributions responsible for the noisevoltage, such as thermal Barkhausen noise, white noise and the noise caused by the piezoelectriceffect.
This approach has been used in our previous work286. In addition to the results obtained there, we
discuss new data on the impact of the bias electric field for different types of noise near the
ferroelectric phase transition. These data are directly related to the observation of the piezoelectriceffect in the cubic phase of BT crystals. Also for the first time the possibility of determining of theelastic properties of the crystal by the noise measurements are discussed.
This work is supported by Russian Foundation for Basic Research (project of №11-02-01317).

284

Y.L. Wang, A.K. Tagantsev, D. Damjanovic, N. Setter, V.K. Yarmarkin, A.I. Sokolov, Anharmonicity of BaTiO3
single crystals, Phys. Rev B, vol. 73, 132103, 2006.
285
J.J Brophy, S.L. Webb, Critical fluctuation in triglecene sulphate, Phys. Rev, vol. 128, 584, 1962.
286
P.S. Bednyakov, I.V. Shnaidshtein, B.A. Strukov, Investigation of the dielectric properties of BaTiO3 single crystalsof different qualities by the thermal noise method, Physics of the Solid State, vol. 53, 350, 2011.

ISAF-P3C-58 ____________________________________________________________________________________________________________________

Band gap asymmetry and local segregation in barium
zirconate titanate epitaxial thin films
Jofre Ventura1, Sergio Hernández2, Adolf Canilas1, Jordi Sancho-Parramón3, Luis Emerson Coy1,
Cèsar Ferrater1, María del Carmen Polo1, María Victoria García-Cuenca1, Manuel Varela1
1

Department de Física Aplicada I Òptica, Universitat de Barcelona, Barcelona, Spain
2
Department d’Electrònica, Universitat de Barcelona, Barcelona, Spain
3Ruđer Bošković Institute, Bijenička 54, Zagreb 10000, Croatia
Email: jofre.ventura@ub.edu

We have grown thin films of BZT on (001)-oriented
Nb:SrTiO3 substrates by pulsed laser deposition.
Structural characterization by X-ray diffractometry
showed that a solid solution with single cube-oncube epitaxial domain is formed across the entire
compositional range. Excluding tetragonal BaTiO3,
the unit cell of BZT is cubic and its volume increases
linearly with Zr content, suggesting properintermixing of Zr and Ti into an average BZT lattice.
However, two-mode behavior of the A1g breathingmode of the oxygen octahedron was detected in the
Raman inelastic scattering spectra of BZT, whichmight be attributed to a heterogeneous distribution of
B-site cations with different Ti-O and Zr-O bonddistances (or local clustering) rather than long-rangeordering288.

Bandgap Energy Eg (eV)The substitution of Ti4+ by Zr4+ in BaZrxTi1-xO3 (BZT) changes its dielectric character from proper
ferroelectric to ferroelectric with pinched phase transition, second-order-like diffuse phasetransition, relaxor behavior, polar cluster and then simple paraelectric287. The dynamic coupling
between BaTiO3 polar nanoregions and BaZrO3 nonpolar ones is thought to be the mechanism
behind such a rich phase diagram. However, these short-range composition variations are notdetectable with X-ray diffraction, which relies on the coherent scattering from many unit cells, andthis topic is thus rarely addressed.
4,2
4,0
3,8
3,6
3,4
3,2
3,0
0,0

0,2

0,4

0,6

0,8

1,0

x in BaZrxTi1-xO3
Fig. 93: Dependence of band gap energy on Zr
content as obtained from spectroscopic
ellipsometry (black points) and assymetricempirical model (orange line).

Furthermore, the dependence of band gap energy
with composition determined from spectroscopic ellipsometry measurements (Fig. 1) does notfollow a bowing parabolic dependence as one could expect from local lattice relaxations alone.
Instead, an asymmetric trend suggests the tendency to the enrichment of one chemical species overanother, as expected from a nonideal solid solution behavior289. An empirical modified Vegard’s
equation with an asymmetry weighted function was successfully fitted to the experimental data.
287

T. Maiti et al., J.Am. Ceram.Soc., vol. 91, p. 1769,-1780, 2008.

288

I. Levin et al., Chem. Mater., vol. 18, p. 854-860, 2006.

289

S. Lee et al., J. Appl. Phys., vol. 107, p. 023523, 2010.

ISAF-P3C-59 ____________________________________________________________________________________________________________________

Determination of the vibrational properties of potassium
titanyl phosphate and identification of domain structuresensitive phonon modes
M. Rüsing1, C. Buchholz1, G. Berth1,2 and A. Zrenner1,2
12Department Physik, Universität Paderborn, 33098 Paderborn, Germany
Center for Optoelectronics and Photonics Paderborn (CeOPP), 33098 Paderborn, Germany
Email: mruesing@mail.upb.de

Ferroelectric materials are commonly used for a wide range of applications in the field of integrated
optics. Their special characteristics such as permanent polarization and nonlinear properties makethem an ideal material for nonlinear devices. Especially the opportunity for quasi- phase-matching
via periodically poled structures is a central topic for the application of this material class. One ofthese ferroelectrics is potassium titanyl phosphate (KTP) which has attracted particular attention
due to its large electro-optical coefficients, high nonlinear coefficients and high damage
threshold290. For advancement in application of periodically poled devices often smaller periods ofalternating domains with opposing polarity are needed. In previous work it has been shown, that
second harmonic generation can be used for imaging of ferroelectric domain walls in KTP291. Dueto complex domain engineering a deep understanding of the material properties is inevitable. HereRaman spectroscopy represents a widely used method for elemental analysis of crystal structures.
In this work confocal Raman spectroscopy was applied on KTP. The confocal application enriches
Raman spectroscopy with the power of high spatial resolution enabling the characterization of thetransferred ferroelectric domain structure. With this combined technology a detailed analysis ofadditional information becomes possible. Raman spectroscopy has already been successfully used
to examine the ferroelectric domain structure in other ferroelectric materials292.
Confocal Raman spectroscopy was applied for studying the vibrational properties of KTP in its
entirety. Therefore polarization-dependent measurements in various scattering configurations were
performed. Our measurements are in good agreement with previous work on KTP293. Furthermore
we have characterized periodically poled potassium titanyl phosphate in terms of polarity- andstructure-sensitive phonon modes. Here we found vibrations which are linked to the ferroelectricdomain structure. This might be due to changes in the polarizability originated from both thedomain boundaries and the inner field distribution. Hence a direct visualization based on the spatial
Raman intensity variation of specific phonon modes becomes possible.
290

M. E. Hagerman, K. R. Poeppelmeier, “Review of the Structure and Processing-Defect-Property Relationships ofPotassium Titanyl Phosphate: A Strategy for Novel Thin-Film Photonic Devices”, Chem. Mater., vol. 7, p. 602-621,
1995.
291

S. I. Bozhevlnyi et al., “Second-harmonic imaging of ferroelectric domain walls”, Appl. Phys. Lett., vol. 73, p. 18141817, 1998.
292

G. Berth et al., “Imaging of the Ferroelectric Domain Structures by Confocal Raman Spectroscopy”, Ferroelectrics.,
vol. 420, p. 44-48, 2011.
293

G. E. Kugel et. al., “The vibrational spectrum of KTiOPO4 single crystal studied by Raman and infrared reflectivity
spectroscopy”, J. Phys C: Solid State Phys., Vol. 21, p. 5565-5583, 1988.

ISAF-P3C-60 ____________________________________________________________________________________________________________________

Novel Electromechanical Analysis to Investigate Small Signal
Properties of Single Fibers
Frank Jörg Clemens1, Francesca Bortolani1
1

Laboratory for High Performance Ceramics, Empa, Dübendorf, Switzerland
Email: frank.clemens@empa.ch

Ferroelectric fibers are interesting for application in ultrasonic, micro-electronic, structure healthmonitoring and energy harvesting systems. For such applications the fibers are embedded into apolymeric matrix to design either AFCs (Active Fiber Composites) or so-called 1-3 composite
structures. Their properties strongly depend on fiber content, fiber diameter and material
composition. In comparison to piezoelectric bulk materials, the characterization method of fibers isundersized. For the characterization of piezoelectric fibers, 1-3 composites with a high fiber content(> 60vol%) are often used. The fibers are aligned in a single direction and the effective ferroelectric,
dielectric and elastic properties of the composite can be determined by conventional dynamic or
quasistatic methods.
With the new equipment (“FerroFib”), properties like small and large signal behavior S(E),dielectric and piezoelectric charge constant as well as polarization on single fibers can be now
evaluated. With the new FerroFib, characterization can be done at different frequencies andtemperatures. Additionally the so-called blocking force can be investigated. The results achieved
with the use of the FerroFib are comparable with the data already published by the group incollaboration with national and international partners. First evaluation was done on Single PZTbased ceramic fibers sintered at 1100, 1150 and 1200°C in a lead enriched atmosphere(PbZrO3+ZrO2). The results were linked with the microstructure and compared with data whichwere measured with other equipment. The piezoelectric coefficient d33 for fibers sintered at 1200°C
is comparable with the one reported in the data sheet of the powder (Fig. 1).

Fig. 1: Piezoelectric coefficient (d33) evolution as a function of sintering temperature.

ISAF-P3C-61 ____________________________________________________________________________________________________________________

Magnetoelectric coupling in Bi1-xAxFeO3 (A=La, Nd) solid
solutions
A.A. Amirov 1, I.K. Kamilov1, L.A. Reznichenko 2, O.N. Razumovskaya 2, I.A. Verbenko 2
1

Institute of Physics, Dagestan Scientific Center of Russian Academy of Sciences, 94 Yaragskogo
Street, Makhachkala, Russia
2
Institutes of Physics, South Federal University, 194 Stachki Street, Russia
e-mail: amiroff_a@mail.ru
The investigation of systems with strongly coupled magnetic and electronic degrees of freedom has
drawn significant interest in recent years due to both challenges for many-body theory as well as forpotential technical applications [1–2]. In connection with the compounds on base of BiFeO3 arevery perspective multiferroic materials due to high temperature of magnetic and ferroelectric phasetransitions, bad conductivity and simple chemical structure [1-2].
High quality ceramics were synthesized on the basic of Bi1-xAxFeO3 (A=La, Nd; x=0-0.2) solid
solutions. Their crystal and grain structure, Mossbauer spectra, dielectric, magnetic, thermal
characteristics were studied. The ac-susceptibility vs. temperature curve of BiFeO3 has a sharp peakat 646 K which corresponds to the antiferromagnetic phase transition and it is confirmed byliterature data [3]. The anomalies of dielectric permeability, spacing parameter, thermal
conductivity and heat capacity near temperature of antiferromagnetic order TN were observed in all
samples and it is related with correlation between magnetic and ferroelectric subsystem which istypical for multiferroics. The magnetization curves also have been studied at the room temperature
for the samples. The magnetization of pure BiFeO3 is small and grows linearly with magnetic field.
Such type of magnetization curve is typical for antiferromagnetic materials. La and Nd substitutions
lead to increase magnetic properties of BiFeO3. The substitution Bi by La or Nd changes thetemperature of the antiferromagnetic order and increases the magnetization of pure BiFeO3. The
magnetic properties change occurs not only on account of magnetic moment and ionic radiuses(lanthanum atom has no its magnetic moment), but also because of La and Nd ions magnetic
moments anisotropy.
The samples were also studied for the presence of the magnetodielectric effect(magnetocapacitance), which is a change in the permittivity of the sample caused by the applicationof a magnetic field,
where ε(H) and ε(0) are the permittivities in a magnetic field and in the absence of it, respectively.
The measurement results showed an increase in magnetodielectric effect is associated with anincrease in the degree of interaction between the dipole and magnetic subsystems. The slower
increase of magnetocapacitance in the range 0.05 ≤ x ≤ 0.1 associated with the change ofpredominant mechanism in the solid solutions, as in 0.15 ≤ x ≤ 0.2 - with the existence of invar
effect due to the appearence of a new monoclinic phase.
1

J. Wang et al., Science 299, 1719 (2003)

2

A.K. Zvezdin and A.P. Pyatakov, Sov. Phys. Usp. 47, 8 (2004).

3

Sosnowska and A. K. Zvezdin, J. Magn. Magn. Mater 140–44, 167 (1995)

ISAF-P3C-62 ____________________________________________________________________________________________________________________

Measurement of Vibration Mode Structure for Adaptive
Vibration Suppression System by Digital Holography
Pavel Psota1,2, Vít Lédl1,2, Roman Doleček1,2, Pavel Mokrý1,2
1

2

TOPTEC Centre, Turnov, Czech RepublicTechnical University of Liberec, Liberec, Czech Republic
Email: psota@ipp.cas.cz

The frequency-shifted digital holographic interferometry (FSDHI) for measurements of vibration
amplitudes in the range of nanometers has been recently introduced and demonstrated294,295. The
FSDHI method addressed some of the drawbacks of conventional methods and was mainly used formeasurements of piezoelectric transformer vibration amplitudes and mode structures296. The
limiting factor for the application of this method is the maximal measured value of the vibration
amplitude without the risk of an ambiguity. The value is approximately 80nm for the frequency
doubled Nd: YAG line.
Since FSDHI enables us to precisely measure vibration amplitudes over the whole inspected areawith a very high lateral resolution, it could also be a very useful tool for measurements of vibration
amplitudes and mode structures in the research and development of adaptive noise suppression
systems. Such measurements would provide a necessary feedback about the system behavior.
The aforementioned issues have motivated the work where we put an effort to the modification of
the FSDHI method with the aim of increasing its dynamic range while keeping its precision. The
essential breakthrough in this paper is an innovative data processing technique based on recurrence
relationship of the first kind Bessel functions. Finally, a measurement method called high dynamic
range - frequency shifted digital holographic interferometry (HDR-FSDHI) was developed. The
method has the ability to measure in a nearly arbitrary range of vibration amplitudes.
The HDR-FSDHI method was applied on a vibration amplitudes measurement of a window. The
window was a vibration system model where the vibrations were suppressed by attachedpiezoelectric macro fiber composite (MFC) actuators shunted by active circuits with a negative
capacitance297. The paper presents the basic principle of the method, the experimental setup andsome results of measurements.

294

V. Ledl, J. Vaclavik, R. Dolecek, and V. Kopecky, “Frequency Shifted Digital Holography for the Measurement ofVibration with Very Small Amplitudes,” in American Institute of Physics Conference Series, 2010.
295

V.Ledl, P.Psota, R.Dolecek, T.Vit, J.Vaclavik,“Testing of recently developed digital holographic mehod for verysmall amplitude measurement” in “Optical Measurement Techniques for Systems and Structures,” Shaker Publishing
BV, 2013.
296

P. Psota, V. Ledl, R. Dolecek, J. Erhart, and V. Kopecky, “Measurement of piezoelectric transformer vibrations bydigital holography,” IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 59, 1962 –1968, 2012.
297

M. Kodejska, P. Mokry, V. Linhart, J. Vaclavik, T. Sluka. “An adaptive vibration suppression system: An alternative
control law for a negative capacitor shunt of a piezoelectric actuator,” IEEE transactions on ultrasonics, ferroelectrics,
and frequency control, 12/2012.

ISAF-P3C-63 ____________________________________________________________________________________________________________________

Nonlinear signatures of periodically poled waveguidestructures in X- and Y-cut lithium niobate
T. Steinrücke1, A. Widhalm1, G. Berth1,2 and A. Zrenner1,2
12Department Physik, Universität Paderborn, 33098 Paderborn, Germany
Center for Optoelectronics and Photonics Paderborn (CeOPP), 33098 Paderborn, Germany
Email: tobiasst@mail.uni-paderborn.de

Essential topic for the efficiency of nonlinear processes is the quality of the transferred ferroelectricdomain structure enabling quasi-phase-matching. In this context periodically poled lithium niobate(PPLN) represents a well-established material system due to its unique combination of properties.
For the noninvasive visualization of such domain structures nonlinear confocal laser scanningmicroscopy is an established tool298. Here, the observed nonlinear signatures mainly depend on thepoling method/fabrication parameters and the crystallographic orientation/area. Up to now theoccurring basic contrast mechanisms are not understood.
Within this work we focus on nonlinear signatures originated from waveguides in X- and Y-cut
PPLN prepared in planar and ridge geometry. Besides the visualization of the periodic domain
structure a depth-resolved analysis of the specific second harmonic (SH) response in the mapped
area of transition has been performed systematically. In fact, second harmonic generation isparticularly a boundary surface effect, therefore specific changes can especially be observed there.
For recorded SH maps of surface-near micro domains in planar and ridge waveguides a similar
nonlinear signature can be found. In the area of polarity reversal domain fragments become visible
linked to the applied electric field. Furthermore a detailed nonlinear analysis of the transition area ofcontrarily poled domains reveals specific signal sequences subject to the period and polarity. A
direct correlation with the nonlinear susceptibility tensor can be expected. In addition, thesesequences exhibit a functional dependence on depth. This might be due to the influence of surface
charge and the inner electric field distribution. Overall a complex interaction of a multitude ofparameters is existent.

a)

298

b)

M. Flörsheimer et al., “Second-harmonic imaging of ferroelectric domains in LiNbO3 with micron resolution inlateral and axial directions”, Appl. Phys. B, vol. 67, p. 593-599, 1998.

Fig. 1: (a) SH intensity as a function of the depth in Y-cut PPLN (period: 16µm, scan increment: 100 nm).
(b) Signal sequences perpendicular to the domain structure in XZ area for three different depths(red: Y = 0 µm, green: Y = -2.2 µm, blue: Y = -4.5 µm).

ISAF-P3C-64 ____________________________________________________________________________________________________________________

Piezoelectric Properties of High Energy Density Pb(Zr,Ti)O 3Pb[(Zn,Ni)1/3Nb2/3]O3 Thick Films for Energy Harvesting Device
Application
Younghun Jeong, Jisun Yun, Junghee Nam, Jeongho Cho, Jonghoo Paik
Electronic Materials Convergence Division, Korea Institute of Ceramic Engineering andTechnology, Seoul, Republic of Korea
Email: yhjeong@kicet.re.kr
Pb(Zr,Ti)O3-Pb[(Zn,Ni)1/3Nb2/3]O3-based piezoelectric ceramics have been intensively studied forenergy harvesting device application299. The piezoelectric transducer material is advantageous forconverting vibration energy into electrical energy, with the mixture of hard and soft characteristics,
on a basis of the criterion for material selection in design of bulk piezoelectric energy harvesters. In
particular, the 0.7Pb(Zr,Ti)O3-0.3Pb[(Zn,Ni)1/3Nb2/3]O3 bulk ceramic sintered at the relatively low
temperature of 950oC exhibited an extremely high transduction coefficient (d33∙g33), where d33 andg33 values are the piezoelectric charge and voltage constant, respectively. In the Pb(Zr,Ti)O3Pb[(Zn,Ni)1/3Nb2/3]O3 solid solution, the magnitude of transduction coefficient is dependent on thecomposition; thus, high energy density material for energy harvesting devices can be achieved by
selecting the best composition with superior transduction coefficient.

0.12
0.10

(d33∙g33) of 20,340ⅹ10-15 m2/N, which iscomparable to that of bulk ceramic.

1500
1250

d33
(pC/N)

1000

ε33T/ ε0

tan δ
(%)

g33
(10-3Vm/N)

d33 · g33
(10-15m2/N)

In this work, high energy density 0.72Pb(Zr0.47Ti0.53)O3-0.28Pb[(Zn0.45Ni0.55)1/3Nb2/3]O3 (PZTPZNN) thick films by a tape casting method were developed for energy harvesting device
application. The PZT-PZNN thick films were sintered at various temperatures from 900oC to
1200oC. When sintered at 1050oC, the 190 μm-thick PZT-PZNN film with a dense andhomogeneous microstructure revealed superior
25000
20000
15000
piezoelectric properties while the films sintered
10000
o
5000
above 1050 C exhibited deteriorated electrical
050characteristics due to the formation of a non40
30
ferroelectric pyrochlore phase of lead zinc
20
o
0.20
10
niobate. In particular, the film sintered at 1050 C
0.18
0.16
revealed an excellent transduction coefficient
0.14

750

500
400
300
200
100

900

950

1000

1050

1100

1150

1200

Sintering temperature(℃)

299

Fig. 94: Variation of d33, εT33/ε0, kp, g33, and d33∙g33
for 0.72Pb(Zr0.47Ti0.53)O30.28Pb[(Zn0.45Ni0.55)1/3Nb2/3]O3 thick films sinteredat various temperatures.

Y.-J. Cha, I.-T. Seo, I.-Y. Kang, S.-B. Shin, J.-H. Choi, S. Nahm, T.-H. Seung, J.-H. Paik, “Title of work”, J. Appl.
Phys., vol. 110, p. 084111, 2011.

ISAF-P3C-65 ____________________________________________________________________________________________________________________

Resolved E-symmetry zone-centre phonons in LiTaO3 and
LiNbO3S. Margueron1, A.Bartasyte2, A.M. Glazer3, E. Simon4, J. Hlinka4, I. Gregora4
1

Laboratoire Matériaux Optiques, Photonique et Systèmes, EA 4423, Lorraine University andSupelec, Metz, France
2
Institute Jean Lamour, (UMR 7198) CNRS – Lorraine University, Nancy, France
3
Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU, UK
4
Institute of Physics AS CR, Prague 8, Czech Republic
Email: samuel.margueron@univ-lorraine.fr

Lithium niobate and lithium tantalate have been the subject of intense studies because of theirapplications in electro-optic, nonlinear-optic, photo-refractive and acoustical devices. The opticalphonon frequencies, damping parameters and intensities are used for the studies of phasetransitions, symmetry, effect of pressure, stress, composition and heterogeneities in thin films,
integrated structures, nano- and bulk materials. It is essential to know the frequencies of all zonecentre optical phonons in calculations of dielectric constant, oblique modes and electro-optic
coefficients. There is good agreement in the reported frequencies of A1-symmetry phonons of
LiNbO3 and LiTaO3. Nevertheless, over the last fifty years there has been much discussion in theliterature concerning the E-symmetry phonons in these materials. To date, this discussion on the Emode assignment is still open.
In this study, all E-symmetry optical phonons at the Γ point of LiNbO3 and LiTaO3 wereexperimentally resolved in the spectra measured by infrared and Raman spectroscopy300. For thispurpose, congruent and nearly stoichiometric crystals of LiNbO3 and LiTaO3, and mixed LiNb1xTaxO3, crystals were studied. The results show that some of the E modes have weak intensities inRaman or infrared spectra. Thus, the complete assignment of E-symmetry modes has been achievedby comparing Raman and infrared data. The wavenumbers of the E-modes, estimatedexperimentally, were close to those calculated theoretically for LN. The clamped relative ordinaryand extraordinary permittivities of LN and LT were calculated using LST relation with good
agreement with Terahertz Time Domain spectroscopy.

300

S. Margueron, A. Bartasyte, A.M. Glazer, E. Simon, J. Hlinka, I. Gregora, and J. Gleize, J. Appl. Phys. 111, 104105,
2012.

ISAF-P3C-66 ____________________________________________________________________________________________________________________

Infrared Photoluminescence in Er Doped Bismuth Layered Ferroelectrics
Dengfeng Peng, Hua Zou, Xusheng Wang301, and Xi Yao(Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai 200092,

China)
Abstract: For ferroelectric materials, doping is usually applied to modify electronic properties,
such as dielectric, ferroelectric, and piezoelectric properties. Recently, multifunctionality has
renewed the interest in ferroelectrics, such as ferroelectric-photo, ferroelectric–elastic, ferroelectric–
elastic–magnetic, ferroelectric– mechanical, integration and/or coupling, which can lead to aremarkable progress with numerous new materials and devices for photovoltaic, spintronic andoptical-electrical-mechanical actuator and sensor applications. Here we examine the Er3+ doped
CaBi4Ti4O15 bismuth layered structured ferroelectrics (BLSF) and demonstrate that a certain
amount of Er3+ doped ceramic sample shows an infrared photoluminescence while simultaneously
keeping ferroelectric characteristics. Photoluminescence excitation spectra show that the samples
have broad excitations from ultraviolet to green regions. The ultraviolet excitation is associated withthe electronic transition within the host solid and the green excitation corresponds to the f-f
transitions of Er3+, respectively. Upon these excitations, the doped samples show a strong infraredemission at room temperature, corresponding to 4I13/2→4I15/2 transition of Er3+. The infrared
photoluminescence of Er3+ reported here has also been discovered in a variety of BLSF oxides suchas BaBi4Ti4O15 SrBi4Ti4O15 and CaBi2Ta2O9 et al., and as series of multifunctional ferroelectrics,
Er3+ doped BLSF materials would be of great importance for the fundamental study of opticalelectrical-mechanical couplings and multifunctional design of future optical-electrical integrated
devices.

301

Corresponding author. Tel.: +86 21 65980544; fax: +86 2165985179;
E-mail: xs-wang@tongji.edu.cn; pengdengfeng1984@163.com.

ISAF-P3C-67 ____________________________________________________________________________________________________________________

Dielectric Characterization of PLZST
Theresa Kainz1, Michael Naderer1, Denis Schütz1, Klaus Reichmann1
1

CD-Laboratory for Advanced Ferroic Oxides, University of Technology, Graz, Austria
Email: theresa.kainz@tugraz.at

Lead zirconate – lead titanate, in short PZT, is a well-known and widespread ferroelectric material
for many applications such as actuators, sensors, transducers and further more.
In the zirconium rich region of the solid solution its structural properties are changing causing a
distortion of the unit cell and opposed neighboring electric dipoles inside the cell resulting in a zeronet spontaneous polarization transforming a ferroelectric material to an antiferroelectric one. The
substitution of lead by aliovalent lanthanum stabilizes the antiferroelectric phase. Applying anelectric field higher than a critical switching field converts the anti-parallel to a parallel dipolealignment inducing a ferroelectric state. Removing the field reverses the alignment to theantiferroelctric phase releasing the stored polarization and producing a current. The change in the
structure enables to store charge and energy respectively at higher electric fields whereconventional ferroelectric materials deteriorate in permittivity.
In this work the electric field induced antiferroelectric-to-ferroelectric phase transition of lanthanum
modified lead zirconate titanate stannate ceramics was investigated in order to clarify the role of tin.
The compositions varied in the tin content replacing the zirconium (Pb0,91La0,06VPb´´0,03)(Zr0,90xTi0,1Snx)O3 (x = 0,01-0,24) were located in the antiferroelectric phase region.
The ceramic was prepared by the conventionally mixed oxide route with an excess of lead added
before calcination. The mixture was calcined at 850°C and sintering was performed at 1250°C for 3
hours.
Dielectric behavior was investigated by measuring the low signal permittivity, capacitance and thepiezoelectric coefficient d33 as well as recording the polarization curves. To display the
microstructure scanning electron microscopy was used in the channeling contrast mode instead of
etching. Furthermore the chemical composition of the as-prepared ceramic could be identified withenergy dispersive x-ray spectroscopy.

ISAF-P3C-68 ____________________________________________________________________________________________________________________

Dielectric relaxations and polarons in Sn2P2S6 ferroelectrics
A. Dziaugys1, J. Banys1, M. Medulych2, A. Molnar2, Yu. Vysochanskii2
1

2

Faculty of Physics, Vilnius University, Lithuania
Institute of Physics and Chemistry of Solid State, Uzhgorod University, Ukraine
Email: andrius.dziaugys@ff.vu.lt

For Sn2P2S6 ferroelectrics the second order phase transition at T0 ≈ 337 K is related withnonlinear interaction of the fully symmetrical and soft polar optic modes. The stereoactivity of tin
cations lone pair electrons determines the chemical bonds changes and charge transfer at transition
into the ferroelectric phase [1,2]. Semiconductive properties of these crystals are determined bysulfur vacancies deep donor states and tin vacancies shallow acceptor states in the energy gap. The
deep energy level of small electron polarons, which are selftrapped at Sn+ cations, and shallow
energy levels of small hole polarons that are trapped at S- anions also induce the local states in thegap [3]. The dielectric spectroscopy for the temperature interval 20 – 380 K have been applied forstudying of slow dynamics of the polaronic particles in by vapor transpot and Bridgemann methods
grown Sn2P2S6 crystals. The dielectric relaxation anomaly was found with dielectric losses
maximum near 60 K at low frequencies. Also two losses peaks were observed in 160 – 260 K
temperature range. Observed dielectric relaxation anomalies are explained by small hole polaronsdynamics with donor-acceptor compensation processes in lattice with tin and sulfur vacancies.
1. Yu. M. Vysochanskii, T. Janssen, R. Currat, R. Folk, J. Banys, J. Grigas, V. Samulionis(Vilnius University Publishung House, Vilnius, 2006).
2. K. Rushchanskii, Yu. Vysochanskii, D. Strauch, Phys. Rev. Letters, 99, 207601 (2007).
3. Yu. Vysochanskii, A. Molnar, R. Yevych, K. Glukhov, M. Medulych, Ferroelectrics, 438, 55(2012).
Acknowledgment
We wish to acknowledge the support of the Research Council of Lithuania funding this work
according to the project “Postdoctoral Fellowship Implementation in Lithuania”.

ISAF-P3C-69 ____________________________________________________________________________________________________________________

Magnetostriction and magnetoelectric effect inintermetallic/relaxor/PVDF composites
Guzdek Piotr1
1

Department of Microelectronics, Institute of Electron Technology, Cracow Division, Zablocie St.
39, 30-701 Cracow, Poland
Email: pguzdek@ite.waw.pl

Magnetostrictive and magnetoelectric materials, a class of smart materials, are drawing muchattention due to their practical applications. Magnetostriction has been defined as an elastic strain
causing a change in shape of material during magnetization. In the magnetic field magnetostrictive
material reorientates its magnetic domains, so it causes physical length change in the material.
Magnetoelectric effect is defined as an induced dielectric polarization under an applied magnetic
field. In the past decade, smart materials have attracted increasing interesting because of theirpractical applications in sensors, actuators, memory devices, transducers, filters, waveguides,
switches, phase invertors
Magnetoelectric effect in bulk and multilayer structures consisting of intermetallic compounds asmagnetostrictive phase and ferroelectric relaxors and PVDF as piezoelectric phase was investigated.
This paper describes the synthesis and tape casting process for ferrimagnetic Tb0.27−xDy0.73−yAx+yFe2
compounds (A = Y, Tb, Yb) and ferroelectric Pb(Fe0.5Ta0.5)O3, Pb(Fe0.5Nb0.5)O3 relaxors. All thecomposites were characterized by scanning electron microscope observations and complex
impedance analysis. Magnetostrictive and ferroelectric grains were distributed homogeneous in a
PVDF matrix. Complex impedance and dielectric permittivity of bulk and layered composites werestudied in a temperature range from –40 to 150°C and frequency range 10 Hz - 2 MHz. Magnetic
hysteresis and magnetization were measured by a vibrating sample magnetometer (VSM) in an
applied magnetic field up to 85 kOe at temperature range from 4K to 400K. The magnetic
hysteresis determined for composites are typical of a mixture of the soft magnetic material with asignificant amount of the paramagnet. The bifurcation of ZFC-FC magnetizations observed for bothcomposites implies spin-glass behavior. Magnetostriction measurements at room temperature werecarried out using Strain Gauge Technique in range of static magnetic field (300-7200 Oe).
Magnetoelectric effect at room temperature was investigated as a function of static magnetic field(300-7200 Oe) and frequency (10 Hz-10 kHz) of sinusoidal modulation magnetic field (5-20 Oe).
Both types of composites exhibit a distinct magnetoelectric effect.

ISAF-P3C-70 ____________________________________________________________________________________________________________________

High-Temperature Structural Transitions in YMn1-xTixO3
M. Tomczyk1, P.M. Vilarinho1, V.V. Laguta2, I. Levin3
1

Department of Ceramics and Glass Engineering, University of Aveiro, 3810-193 Aveiro, Portugal
2
Institute of Physics AS CR, Cukrovarnicka 10, 162 53 Prague, Czech Republic
3
Materials Measurement Science Division, NIST, Gaithersburg, MD 20899,USA
Email: paula.vilarinho@ua.pt.

YMnO3, which at ambient pressure crystallizes with a layered hexagonal structure, has attracted
much interest because of its multiferroic properties302. YMnO3 undergoes two phase transitions: a
non-polar to polar (P63/mmc to P63cm) transition at 1273 K303, which is accompanied by tripling of
the unit-cell volume, and a subtle, isosymmetric, (P63cm to P63cm) transition at 920 K304. This
lower temperature phase transition, the nature of which still remains uncertain, has been associatedwith the Curie temperature (TC) of YMnO3.
However, recent neutron diffraction studies of
YMnO3305 suggested that the macroscopic polarization is non-zero even above TC and drops
abruptly below Tc. These results, which remained uncommented in the literature, question our
understanding of the ferroelectric transition in YMnO3.
In the present study, we used variable-temperature X-ray and neutron diffraction to examine theeffects of Ti substitutions in YMn1-xTixO3 (0<x<0.15) solid solutions on the phase transitions in thissystem.
The temperature of the high-temperature transition P63/mmc-P63/cm decreases
continuously as x increases. At lower temperatures (from 650 K to 800 K, depending on x), we
observed an anomalous behavior of the c-lattice parameter, which appears to be connected to an
isosymmetric transition of the type seen in YMnO3.
In YMnO3, structural parameters are
independent of the sample atmosphere. By contrast, in YMn1-xTixO3, the structural anomalies vary
markedly with the atmosphere, suggesting strong effects of point defects induced by the substitutionof Ti on the supposed structural transition. Apparently, the presence of point defects enhances the
structural changes associated with this transition. In the talk, we will discuss our findings thatprovide new insights into the nature of structural transitions in YMnO3 and Y(Mn,Ti)O3 solid
solutions.

302

W. Prellier, M.P. Singh, P. Murugvel, J. Phys.: Condens. Matter, vol.17, R803, 2005.
K. Lukaszewicz, J. Karut-Kalicinska, Ferroelectrics, vol. 7, 81,1974.
I.G. Ismailzade, S.A. Kizhaev, Sov. Phys. Solid. State, vol.7, 236, 1965.
305
A.S. Gibbs, K.S. Knight, P. Lightfoot, Phys. Rev. B, vol. 83,184418, 2005.
303
304

Piezoelectric MEMSCLUB A
Thursday, July 25 2013, 08:30 am - 10:00 am
Chair:Paul Muralt
EPFL

ISAF4-K1-1 _____________________________________________________________________________________________________________________

3D MEMS Piezoelectric Ultrasound Transducer Technology
Arman Hajati, Dimitre Latev, Deane Gardner
FUJIFILM Dimatix, Inc., Santa Clara, CA 95050 USA
Email: ahajati@fujifilm.com
Here we present a novel ultrasound transducer technology called Clarinet™306 based on a
combination of micromachined 3D dome-shaped piezoelectric resonators arranged in a uniqueflexible architecture.
As an alternative to bulk piezoelectric transducers,
MEMS-based ultrasound transducers have recently
emerged aiming to offer advantages such as increased
bandwidth, flexible geometries, natural acoustic matchwith water, reduced voltage requirements, mixing ofdifferent resonant frequencies, and potential for
integration with supporting electronic circuits.
However, difficulties in fabricating reliable MEMS
structures combined with various technical issues have
prevented PMUT and CMUT technologies frombecoming a viable and practical solution up to now.

Pulse Echo (V)In this paper we present CLARINET™ which can beseen as a monolithic integrated ultrasonic circuit
manufactured by lithography with four main Fig. 95: Optical and SEM image of the device
Pulse Echo Response, 2way
FDMX LF-Mix, Tx: 100ns, 40V Pulse, No Lens, Single Channel, Depth: 15mm
advantages over bulk piezoelectric transducers: cost,
Measured by Fujifilm Sonosite, Filename: 18123456.F40
1
performance, customization, and miniaturization
PK+: 0.8606V
PK-: -1.263V
0.5
Pk-Pk: 2.017V
capability. Our proprietary high performance PZNT
0film is implemented in 3D dome-shaped structures-0.5
which form the basic resonating cells. In a process-1
similar to designing RFIC filters, adjustable frequency
-1.5
19.5
20
20.5
21
21.5
22
22.5
23
23.5
24
response is realized by mixing these basic cells andTime (s)modifying the dimensions by lithography.
Pulse Echo Spectrum-20

Echo (dB)

FC: 4.38MHz-30
Exploiting a 5th order filter design, a 5MHz linear
6dB BW: 64.53%
10dB BW: 78.12%-40
arrayis designed, fabricated and tested and unique-50-60
features such as high sensitivity (more than 100kPa/V),-70
adjustable wide-bandwidth frequency response (greater-80
than 55%), CMOS-compatible low transmit voltage
-90
0
5
10
15
20
25
30
Frequency (MHz)(2V-20V), low electrical impedance (less than 50Ohms), efficient electromechanical coupling (greater
Fig. 2: Single channel pulse echo responsethan 45%), and reliable monolithic fabrication aredemonstrated. Updated testing results including the receiving sensitivity and the two-way pulse
echo response will be presented for the first time.We envision that this technology can be

306

A. Hajati et al, “Three-dimensional micro electromechanical system piezoelectric ultrasound transducer”, Appl.
Phys. Lett., vol. 101, 253101, 2012.

implemented as a desirable solution in high performance 3D/4D, low-power portable and in-vivo
imaging systems.

ISAF4-K1-2 _____________________________________________________________________________________________________________________

Ferroelectric Film Bulk Acoustic Wave Resonators for Liquid
Viscosity Sensing
Andrei Vorobiev and Spartak Gevorgian
Department of Microtechnology and Nanoscience, Chalmers University of Technology,
Gothenburg, Sweden
Email: andrei.vorobiev@chalmers.se
The piezoelectric film bulk acoustic wave (BAW) resonators have proven to be suitable for application
as high accuracy and CMOS-compatible liquid viscosity sensors. However, the non-ferroelectric BAW
sensors, usually operating in thickness shear mode, always have a longitudinal wave component
generated as by-product due to inclination of polarization. The longitudinal contribution leads to a fluid
turbulence at the device surface, which disturbs the conditions of the shear viscosity measurements. In
the proposed paper we present, for the first time, the concept of the liquid viscosity sensing with theferroelectric BAW resonators allowing for realization of truly shear displacement. The advantage of theferroelectric based sensors is associated with the nature of the dc field induced piezoelectric effect. The
induced polarization strictly coincides with the electric field. This allows for exclusively shear
displacement and, hence, laminar shear of fluid at the resonator vertical side walls.
The sensors have been fabricated as the BAW solidly
mounted resonators, based on the 0.67BiFeO30.33BaTiO3 multiferroic films307, operating at
4.2 GHz resonant frequency and 10 V dc bias. In theexperiments the resonators have been covered bylayers of liquids with different viscosity and thickness
controlled to be about 250 µm.
The measured resonator response has been analyzed
using the proposed model of a harmonic oscillator
damped by a viscous force in the form of the Stokes’
low. It can be seen from Fig. 1 that the hyperbolic
dependence of the resonator Q-factor, predicted by Fig. 96: Q-factors and sensitivity of thethe model, agrees well with the measurements. The ferroelectric BAW vs. viscosity. The Q-factor
sensitivity of the resonator with the Q=200 is ca dependence lines are hyperbolic fitting curves.
10 (mPa s)-1, which is high enough for the accuratecharacterization of water and other low viscosity liquids. Analysis indicates that the resonator effective
mass is much larger than the added mass of the liquids, which explains the observed insensitivity of the
Q-factor and resonance frequency to the liquid layer thickness. This makes the measurements simpler
and more accurate since does not involve the liquid layer thickness and mass density.
Another advantage of the proposed sensors is possibility of simultaneous monitoring of the liquid
temperature using inherent temperature dependence of the ferroelectric permittivity. This is a very
useful feature, since the viscosity of many liquids is strongly temperature dependent. Estimates showthat the temperature can be monitored with accuracy of ca 0.01 K.

307

A. Vorobiev, S. Gevorgian, N. Martirisyan, M. Löffler, and E. Olsson “Intrinsically tunable
0.67BiFeO3-0.33BaTiO3 thin film bulk acoustic wave resonators”, Appl. Phys. Lett., vol. 101, p. 232903 -5, 2012.

ISAF4-K1-3 _____________________________________________________________________________________________________________________New Human Machine Interface Devices Usinga Piezoelectric Poly(L-lactic acid) Film
Masamichi Ando1,2, Hideki Kawamura1, Hiroaki .Kitada1, Takafumi .Inoue1, Yoshiro Tajitsu2
1

Organic Film Devices Project/Murata Manufacturing Co. ,Ltd., Nagaokakyo-shi, Kyoto/Japan
2
Graduate School of Engineering/Kansai University, Suita-shi, Osaka/Japan
Email: andoh@murata.co.jp

110

20

20

Electric charge (pC)

Poly(lactic acid) (PLA) has become widely known as an
60
1600
ecofriendly biomass polymer. The lactic acid monomer has an
A B C D20
1400
asymmetric carbon; thus, it has chirality. If the L-lactide is1200
CD
polymerized, then the PLA polymer is called an L-type PLA or a1000
poly(L-lactic acid) (PLLA). If the polymer undergoes drawing or
B
800
elongation, then they exhibit shear piezoelectricity308. In
A
600
collaboration with Mitsui Chemicals, we have produced a stable
400
PLLA film with a sufficient piezoelectric constant to be used forsensing applications309. The piezoelectric PLLA film does not
200(mm)
have pyroelectricity, because it does not have intrinsic
0
0
200
400
600
polarization. Therefore, even if the PLLA film is used for a
Load (g)human-machine interface (HMI), which operates by direct
Fig.1: Relationship between the applied
operation by hand, there is no incorrect detection due to heat.
It has been recognized that a capacitive-type touch panel (CTP) load and generated electric charge.
is a very useful HMI for a smart phone and a tablet type personal
computer. The touch panel with a pressure recognition function has beenZ
desired for more often these days. The PLLA film is very suitable for a
CTP as a pressure sensing film. Pressure due to the slight bending of the
TX
glass during touch screen applications can be detected accurately.
Z
Furthermore, because the PLLA has very high transparency, it is suitable
TX
for touch panel pressure sensing, in which transparency is required. Figure
1 shows the relationship between the load on the glass and the generated
electric charge. The PLLA film is attached on the glass. The glass size is110(L)×60(W)×0.5(T) mm. The PLLA film forming the electrode on both (a) Top viewprincipal surfaces is 0.07 mm in thickness and has a piezoelectricity, d14 =
TX
TX
Z
Z
6.0 pC N−1. The four sides of the glass are attached to a case,
PLLA
approximately the size of a smart phone. Although there is some differenceZ
Z
Z
in the sensitivity due to the position of the applied pressure, the sensitivity
RXRX
can be equalized and linearized by combining it with position detection (b) AA-Cross-sectional view
information. Figure 2 shows an example of multiple electrodes formed on
the PLLA film, which consists of a pressure detection electrode and an Fig.2: Multiple electrodes.
electrode for the CTP. Additional electrode layers are not required with such a composition; thus, theresulting pressure detection touch panel is highly transparent.
A

E. Fukada: IEEE Trans. Dielectr. Electr. Insul. 13 (2006) 1110.

2

M. Ando, H. Kawamura, K. Kageyama, and Y. Tajitsu: Jpn. J. Appl. Phys. 51 (2012) 09LD14

RX

RX

A

1

ISAF4-K1-4 _____________________________________________________________________________________________________________________

Piezoelectric Microelectromechanical Systems (MEMS) Across Length Scales
R. Johnson, D. Wilke, C. Yeager, T. N. Jackson, and S. Trolier-McKinstry: Penn State
P. Reid, V. Cotroneo, and D. Schwartz: SAO
D. Newns, G. Martyna, T. Shaw, M. Copel, T. Theis: IBM

Abstract
Piezoelectric thin films are of increasing interest in low voltage microelectromechanicalsystems (MEMS) for sensing, actuation, and energy harvesting. They also serve as model systems
to study fundamental behavior in piezoelectrics. Piezoelectric MEMS devices range over a wide
range of length scales. On the extreme upper end are large area devices for applications such as
adaptive optics. In this case, the piezoelectric film can be used to produce local deformation of amirror surface, in order to correct figure errors associated with fabrication of the component or tocorrect for atmospheric distortion. For example, should a mission such as Gen-X be flown, it would
require up to 10,000 m2 of actuatable optics in order to correct the figures of the nested hyperboloid
reflecting segments. In this case, the “micro” in “microelectromechanical systems” is clearly amisnomer, although the fabrication techniques would involve conventional micromachining forpatterning of the electrodes. Many piezoelectric MEMS devices are fabricated at intermediate
length scales (tens of microns to 1 cm). Here, examples will be given of piezoelectric energy
harvesting devices. We have recently demonstrated improvements in the energy harvesting figureof merit for the piezoelectric layer by factors of 4 – 10. Finally, piezoelectric MEMS are also
attracting attention at a substantially smaller size scale (tens of nm) as a potential replacement for
CMOS electronics. Examples of the materials choice as well as specific devices at all three of theselength scales will also be discussed.

ISAF4-K1-5 _____________________________________________________________________________________________________________________A MEMS AlN transducer array for use as a cochlear implant
Katherine Knisely and Karl Grosh
Mechanical Engineering, University of Michigan, Ann Arbor, MI
Email: kknisely@umich.edu
Aluminum nitride (AlN) has emerged as an excellent material for a variety of MEMS applications
because of its high electrical resistance, low dielectric loss, and high sound velocity. Recently,
MEMS sensors using AlN in a bimorph cantilever configuration have been demonstrated with low
noise floors and good sensitivity310. Because of its very low dielectric loss factor and relatively
simple deposition process as a thin film, AlN is an excellent material for microphones. The
cantilever configuration has many benefits, including a more linear response, control of thefrequency response using simple changes to the beam geometry, and simple adaptation frommicrophone to hydrophone.
We present an array of AlN bimorph cantilevers, fabricated using MEMS batch processing
techniques, with applications both as a hydrophone array and as a completely implantable cochlear
implant (CI).
A silicon backbone supports five 400μm wide, 5μm thick bimorph(Platinum/aluminum nitride (AlN) stack) cantilevers, each of which is designed to have aresonance, in water, that corresponds to its tonotopic locationin the guinea pig cochlea (20-40kHz). A 1mm wide, 10μm
thick parylene and gold ribbon cable extends 3cm from theprobe to an electrode bay, where electrical connections toeach cantilever are accessed. The frequency response of a
cantilever in a viscous fluid is predicted using a modified
Euler-Bernoulli equation that includes fluid loading andviscous damping311, and is measured in air using a laser
vibrometer and in water using a calibrated underwatertransducer pair.

Fig. 97: The fabricated device. The

Unlike traditional CIs, this probe is designed to transduce cantilever array (left, circled, with amechanical vibrations of the cochlear fluid into electrical closeup on the right ) is connected tosignals that stimulate the auditory nerves without the use of an an electrode bay for external electricalexternal sound processing unit. Vibrations in the cochlear monitoring by a flexible parylene-gold
fluid deflect the cantilevers, resulting in a potential forming ribbon cable.
on the outer electrode layers of the cantilever. The outerelectrodes are in electrical contact with the ionic fluid of the cochlea, producing a current in thecochlear fluid that is passed to the auditory nerves. In this design the energy is locally sensed andconverted into stimulation within the cochlea, therefore our design does not require the traditionalsignal processing unit, microphone, and transceiver that current CIs employ. Benefits of this design
include lower power, smaller size, and lower latency when compared with current commercial CIs.

310
311

R. Littrell and K. Grosh, Journal of Microelectromechanical Systems 21(2), 406 (2012).
JE Sader. Journal of. Applied Physics, 84:64–76, 1998.

Modeling: multiscale, first-principles,...
CLUB B
Thursday, July 25 2013, 08:30 am - 10:00 am
Chair:

George Rossetti
University of Connecticut

ISAF1-K2-1 _____________________________________________________________________________________________________________________

Point defects in LiNbO3 from density functional theory using
local and hybrid electron XC functionals
Yanlu Li, Simone Sanna, Wolf Gero Schmidt
Lehrstuhl für Theoretische Physik, Universität Paderborn, 33095 Paderborn, Germany
Email: liyanlu.cs@gmail.com
Lithium Niobate (LiNbO3, LN) is a versatile material of great technological importance with many
practical applications. Numerous experimental investigations suggest that defects, caused by its
non-stoichiometry, critically affect many physical properties of LN. However, the precise defectstructures and energetics are still under debate. This is due to the wealth of possible defects formed
in a ternary compound and the charge compensation mechanisms required to achieve charge
neutrality. Here, the defect species related to Li2O deficiency are determined by density functional
theory (DFT) in the framework of both generalized gradient approximation (GGA) and hybrid
functionals (HSE06) to describe the electron exchange and correlation (XC).
The calculated electronic band gap of bulk LN is 5.21eV and 3.36eV within HSE06 and GGA,
respectively. The HSE06 result agrees closelywith earlier GW calculations312. Also the lattice
parameters determined within HSE06 describe
the experiment better than GGA results. Marked
differences between local and hybrid XC
functionals are found as well for the defectenergies: HSE06 increases the Li and Nb vacancy(VLi and VNb) formation energies and decreases
the Nb antisite (NbLi) energy with respect to the
GGA. Transition levels not detected in previous
GGA calculations are observed, e.g., for VLi. The
charge state of VNb changes from 0 to -5 directly
in both calculation schemes, showing a so-called
negative-U effect. This behavior is quite different
fromprevious
reports313,314,
however. Fig. 98: Defect formation energies of NbLi (black
Additionally, NbLi is less strongly bonded to VNb lines), VLi (red lines) and VNb (blue lines) as athan VLi. The NbLi-VNb binding energy increases function of Fermi energy calculated by DFTGGA(solid lines) and HSE06 (dash lines). The
by decreasing the magnitude of the defect pair Fermi energies range from 0 to 3.36eV by DFT andcharge. The present findings provide new insight 0 to 5.21eV by HSE06.
into the energetics and microscopic structures of
LN point defects, vital for its macroscopic properties.
312

W. G. Schmidt, M. Albrecht, S. Wippermann, S. Blankenburg, E. Rauls, “LiNbO3 ground- and excited-state
properties from first-principles calculations”, Phys. Rev. B, vol. 77, p. 035106, 2008.
313

H. X. Xu, D. Lee, J. He, S. B. Sinnott, V. Gopalan, V. Dierolf, S. R. Phillpot, “Stability of intrinsic defects anddefect clusters in LiNbO3 from density functional theory calculations”, Phys. Rev. B, vol. 78, p. 174103, 2008.
314

Q. K. Li, B. Wang, C. H. Woo, H. Wang, R. Wang, “First-principles study on the formation energies of intrinsic
defects in LiNbO3”, J. Phys. Chem. Solid, vol. 68, p. 1336-1340, 2007.

ISAF1-K2-2 _____________________________________________________________________________________________________________________First-principles study of defect and domain wall interactions in
PbTiO3
Anand Chandrasekaran1,2, Dragan Damjanovic2, Nava Setter2 and Nicola Marzari1
1

Laboratory of Theory and Simulation of Materials, EPFL, Lasusanne, Switzerland
2
Ceramic Laboratory, EPFL, Lasusanne, Switzerland
Email: anand.chandrasekaran@epfl.ch

The properties of ferroelectric materials such as Lead Zirconate Titanate (PZT) are heavily
influenced by the addition of dopants. These dopants lead to the formation of defects and defectassociates which then interact with domain walls. In the case of iron doped materials, firstprinciples calculations show the formation of defect associates involving the acceptor subtitutional
defectand a charged oxygen vacancy. This defect associate shows a strong tendency to align in the
direction of the bulk polarization (Fig. 1). Nudged elastic band calculations are used to determine
the barrier energy for the hopping of oxygen vacancies around the acceptor dopant. It is shown that
defect alignment is likely responsible for ageing phenomena in acceptor doped PZT. Calculations
also reveal that lead and oxygen divacancies are capable of forming polar defect complexes whichalign with the bulk polarization. However, calculations on donor doped materials do not indicate theformation of polar defect complexes involving donor substitutional defects. The interaction of
defects with 180 degree domain walls is also studied. It is observed that both isolated defects anddefect associates are more stable at 180 degree domain wall. However, polar defect complexes
show a highly asymmetric potential at the domain wall due to the interaction of the defectpolarization with the bulk polarization. Fig. 2 depicts the movement of the domain wall across a
defect. The relative pinning characteristics of different defects are then compared to develop anunderstanding of defect-domain wall interactions in both pure and doped PbTiO3.

Fig. 1 Defect associate between iron and oxygen vacancy.

Fig. 2 Schematic of the movement of the domain wall in the presence of the defect. (a)Initial stateof supercell with defect oriented in the direction of the bulk. (b)Final state with defect oriented inthe opposite direction of the bulk. This temporary disalignment is the driving force for ageing andloop pinching

ISAF1-K2-3 _____________________________________________________________________________________________________________________

Self-Consistent Modeling of the Depolarization Field
Evolution during Polarization Switching in Polycrystalline
Ferroelectrics
Yuri A. Genenko, Jens Wehner, Heinz von Seggern
Institute of Materials Science/Technische Universität Darmstadt, Darmstadt, Germany
Email: genenko@mm.tu-darmstadt.de
The development of polarization during switching in thin ferroelectric films315,316 as well as in bulk
polycrystalline ferroelectrics317 exhibits a slowing down at long poling times in contrast to thepredictions of the classical Kolmogorov-Avrami-Ishibashi model with a single switching time.
This phenomenon is often interpreted as a dispersive polarization reversal characterized by a wide
spectrum of switching times1-3. On the other hand, such interpretations typically ignore the feedback effect of the depolarization field changing during polarization switching. Recently an attempt
to account for this effect in a thin ferroelectric film was made by Lou in a self-consistent onedimensional model318, which resulted in switching curves similar to those of the experiment2.
In the current communication it will be shown that identical results can be obtained by solving asingle first-order differential equation which self-consistently describes the polarization
switching319 instead of using a system of 100 coupled differential equations4. Furthermore, by
combining this equation with two-dimensional finite-element calculations of the depolarization fielda model for the self-consistent analysis of the polarization response in bulk disordered ferroelectrics
accounting for both the statistical distribution of switching times and the feed-back effect of thedepolarization fields was developed for the first time. The results are compared with previous
statistical descriptions of disordered ferroelectric systems.

315

A.K. Tagantsev, I. Stolichnov, N. Setter, J. S. Cross, M. Tsukada, “Non-Kolmogorov-Avrami switching kinetics inferroelectric thin films”, Phys. Rev. B, vol. 66, 214109, 2002.
316

J.Y. Jo, H.S. Han, J.-G. Yoon, T.K. Song, S.-H. Kim, and T.W. Noh, “Domain switching kinetics in disorderedferroelectric thin films”, Phys. Rev. Lett., vol. 99, 267602, 2007.
317

Y.A. Genenko, S. Zhukov, S.V. Yampolskii, J. Schütrumpf, R. Dittmer, W. Jo, H. Kungl , M.J. Hoffmann, and H.
von Seggern, “Universal polarization switching behavior of disordered ferroelectrics”, Adv. Funct. Mater. vol. 22, p.
2058-2066, 2012.
318
319

X.J. Lou, “Statistical switching kinetics of ferroelectrics”, J. Phys.: Condens. Matter, vol. 21, 012207, 2009.

H. von Seggern and G.F. Leal Ferreira, "Switching dynamics in poly(vinylidene fluoride) and copolymers", Appl.
Phys. Lett., vol. 83, p. 3353-3355, 2003.

ISAF1-K2-4 _____________________________________________________________________________________________________________________FBAR tuning from first principles and high-order electrostriction
Alexander Kvasov1, Alexander Tagantsev1
1

Ceramics Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
Email: alexander.kvasov@epfl.ch

Tunable thin film bulk acoustic wave resonators (TFBARs) based on BaxSr1-xTiO3 (BST) thin films
are considered for frequency agile applications due to the DC bias dependent parameters of theresonator. TFBARs seem to be a very attractive component for microwave applications since they
offer possibilities to increase the functionality of telecommunication systems. At the same time, forpractical application as tunable microwave filters simultaneous tuning of resonance andantiresonance frequencies is highly desired.
In [1] it was demonstrated that, for TFBAR antiresonance frequency fAR tuning, it is important tomtake into account nonlinear electrostriction m111 ( F  ...  111 P12 u12  ... ) which being traditionally2
neglected [2] is unknown experimentally.
In this work m111 was calculated for the first time using ab initio methods for BST (Table I). To
improve the reliability of the obtained results we used two different packages: Vienna Ab-initio
Simulation Package (VASP) and Quantum ESPRESSO (QE).

m
F

VASP

QE

SrTiO3 (x = 0)-2.2±0.4-3.0±0.4

BaTiO3 (x = 1)-2.8±0.4-2.8±0.4m111, 1011

Table 1. Data obtained with the first principles
calculations. m111 - nonlinear electrostriction
coefficient.

It was established that for BST based TFBARs the antiresonance tuning is smaller than previously
made estimations. Our calculations demonstrate the importance of taking into account bothnonlinear electrostriction m111 and background permittivity εb which are equally responsible for thetuning (Fig. 1).
Figure 1. Modelled dependences of antiresonancefrequency fAR tuning on relative tunability nr for
the TFBAR using the [001]-oriented thin film of
BST with x=0.25. Dashed lines show theantiresonance behaviour without taking into
account background permittivity εb or high-orderelectrostriction m111. Relative tunability nr isdefined as:.

ISAF1-K2-5 _____________________________________________________________________________________________________________________

Precursor dynamics, incipient ferroelectricity and huge anharmonicity in antiferroelectriclead zirconate PbZrO3
Annette Bussmann-Holder1, Jae-Hyeon Ko2, Andrzej Majchrowski3 and Krystian Roleder4
2

1
Max Planck Institut für Festkörperforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany
Department of Physics, Hallym University, Hallymdaehakgil, Chuncheon, Gangwondo 200-702,
Korea
3
Military University of Technology, Warsaw, Poland and4Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007 Katowice, Poland

To understand better the phase transition mechanism of PbZrO3 (PZO) the lattice dynamics of thisantiferroelectric compound are investigated within the polarizability model, with emphasis on the
cubic to orthorhombic phase transition. Similarly to ferroelectric transitions in ABO3 perovskites,polar dynamical ferroelectric type clusters develop and grow in size upon approaching TC from thehigh temperature side and never form a homogeneous state. Simultaneously, elastic anomalies set inand compete with polar cluster dynamics. These unusual dynamics are responsible for precursor
effects that drive the PZO lattice towards an incipient ferroelectric state. Comparison of the model
calculations with temperature dependencies of elastic coefficients measured on PZO single crystals
reveals striking similarity.

ISAF1-K2-6 _____________________________________________________________________________________________________________________

Gauge Theory for Relaxor Ferroelectrics
Yousra Nahas, Igor Kornev
Laboratoire Propriétés et Modélisations des Solides, Ecole Centrale Paris, France
Email: yousra.nahas@ecp.fr , igor.kornev@ecp.fr
When examining the occurrence of the relaxor behavior, one of the main requirements appears to belattice disorder320,321. Due to their heterovalency and their size mismatch, substitutional impurities
and accompanying vacancies can act as sources of both random electric and strain fields. These
defects can introduce substantial disorder, therefore destroying translational and rotational
symmetries and hampering the onset of long-range order. Furthermore, the presence of an impurity
on a given site can induce dipoles in its vicinity, resulting in correlated orientational degrees of
freedom that cause symmetry breaking at the local scale1. A corollary feature of disorder in relaxors
is thus the dualism between their local and average structures. The coexistence of locally preferred
structures and an absent macroscopical
phase change1,2, gives local symmetry
back its preeminence.
We argue that these two features, namely
the lattice disorder and the local vs global
twofoldness, can be described within thelocal gauge theory322. This surmise
stands on the belief that the effects ofrandom local environments stemmingfrom lattice disorder can be probed
within local gauge transformations
involving local symmetry, i.e. an
extended symmetry allowing independenttransformations at different points in
Fig. 99: Temperature dependence of the scaled polarization
space.

for (from up to down) the pure system PZT and for PLZT with
5%, 10%, 15% and 20% of La3+. Upper and lower inserts
Starting with the first-principles-based
show the streamlines associated to the dipole moments vector
effective Hamiltonian approach323, we field at 50K in the cases of PZT and PLZT with 10% of La3+,
formulate our model in a manifestly respectively.

gauge-invariant manner, based upon
continuous local symmetry and lattice gauge theory4. Technically, we focus on disordered (Pb1xLax) (Zr60Ti40) O3 solid solutions. The B-site disorder alone leads to the well known ferroelectric
PZT, whereas the A-site disorder can lead to the relaxor behavior1. This latter disorder is seen as asource of a partially quenched random gauge field. The presented approach incorporates
ferroelectric and elastic degrees of freedom, as well as gauge fields taking values in a Lie group andreproduces the main static features of PLZT systems (e.g. Fig.1).
320

G. A. Samara, Solid State Physics 56 (2001) 239
W. Kleeman, Journal of materials science 41 (2006) 129-136
322
K. Moriyasu, An elementary primer for gauge theory , World Scientific, Singapore, 1983
323
W. Zhong, D. Vanderbilt, K. Rabe, Phys. Rev. Lett. 73 (1994) 1861 ; Phys. Rev. B 52 (1995) 6301
321

This work is partially supported by the ERA. Net RUS grant, STProjects-133, NANO-C.

Local Phenomena
CLUB C
Thursday, July 25 2013, 08:30 am - 10:00 am
Chair:

Yasuo Cho
Tohoku University

ISAF1-K3-1 _____________________________________________________________________________________________________________________

Multiple bias-induced transitions and multiferroic states in
half-doped La0.5Ca0.5MnO3 manganite
Fábio. Figueiras1,2,3, Igor. K. Bdikin4, Vitor. S. Amaral1,2, Andrei. L. Kholkin2,5
1

Physics’ Department, University of Aveiro, 3810-193 Aveiro, Portugal
2
CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
3
IFIMUP & IN, Physics & Astronomy Dep., Science Fac., Porto Univ., 4196-007 Porto, Portugal
4
Mechanics’ Eng. Department & TEMA, University of Aveiro, 3810-193 Aveiro, Portugal
5
Materials' Eng. & Ceramics Department, University of Aveiro, 3810-193 Aveiro, Portugal
Email: ffigueiras@ua,pt
Phase separation, competition and nanoscale coexistence are ubiquitous characteristics of strongly
correlated electronic complex oxides, such as mixed valence manganites. In La1-xCaxMnO3+δ
system phase diagram 324, a delicate balance occurs near half doping (x ~0.5) with a metallic
ferromagnetic state for Mn4+/Mn3+ ≤ 1, whereas for Mn4+/Mn3+ ≥ 1 brings anantiferromagnetic/charge-ordered insulator state. The nanoscopic electronic phase coexistence andinhomogeneity turns this material highly sensitive to external factors namely, ionic doping,temperature, electric/magnetic external fields and pressure. Further, the possibility of simultaneouspresence of site- and bond-centered orbital ordering, can lead to a break of structural inversion
symmetry allowing the conditions to the appearance of ferroelectricity 325. This potentiates the
emergence of at least three distinct electronic transport states mechanisms, by suitable stimulus. The
propensity of manganites to tolerate local chemical/structural/charge inhomogeneities constitutes
therefore a paradigmatic category of self-composite multiferroic system where metastable phases
coexist in nearby nanoscale volumes. Previous works show clear bias-induced piezocontrast andlocal hysteresis loops could be investigated provided evidence of the existence of a local polar statewith ferroelectric response at room temperature, even above charge order transition temperature
326,327. In this framework we studied polycrystalline La0.5Ca0.5MnO3+δ combining Force Microscopy
techniques (PFM, MFM, KFM, IV) to study the effects of nano-indentation and bias lithography
leading to local modifications of electrochemical or electromechanical properties at the surface of
these manganite systems 328. The bias steering of phase transitions and lithographically setting
single domain (~500 nm) electronic metastable phases was demonstrated at room temperature(poling voltages up to 30 V), inducing either enhance conductivity or insulating-ferroelectric
behaviors. The enlarged possibilities near multiphase competition and nano coexistence (such as inhalf-doped manganite) opens a new pathway to achieve spatially localized multiferroic effects andartificial functionalities from a single base material having large potential for technology
applications as data storage and processing.

324

E. Dagotto, et al Physics Reports vol.344, p. 1-153, 2001.

325

D. Efremov et al, Nature materials, 3, 853-856, 2004

326

Ch. Jooss, et al, PNAS vol. 104, no. 34 ,p. 13597-13602, 2007 and

327

R. F. Mamin, et al, App. Phys. Lett. Vol. 94, p. 222901, 2009.

328

S. V. Kalilin et al., Mat. Today Vol. 11, no. 11, p. 16-27, 2008.

The work was partially supported by FCT grant
PTDC/FIS/105416/2008 and PEst-C/CTM/LA0011/2011

SFRH/BPD/80663/2011,

project

ISAF1-K3-2 _____________________________________________________________________________________________________________________

Peptide nanotubes as building blocks for nanosize transducers
and sensors
Shima Dayarian1, Alisa Rudnitskaya2, Maciej Wojtas1, Svitlana Kopyl3, E. Bosne1, Ivonne
Delgadillo4, Andrei Kholkin1
1

Department of Materials and Ceramic Eng. & CICECO, University of Aveiro, Aveiro, Portugal
2
Chemistry Department & CESAM, University of Aveiro, Aveiro, Portugal
3
Department of Mechanical Engineering & TEMA, University of Aveiro, Aveiro, Portugal
4
Chemistry Department & QOPNA, University of Aveiro, Aveiro, Portugal
Email: kholkin@ua.com

Peptide nanotubes (PNT) based on the self-organization of the dipeptide diphenylalanine havereceived much attention as a promising nanostructure. Self-organizing nanotubes based on theseparticular dipeptides display unique biological and physical properties such as inherent
biocompatibility, extraordinary thermal stability and organic solvent stability, high Young’s
modulus and bending stiffness. Recently, a strong piezoelectric activity was discovered in aromatic
PNTs329. This functional property is very important as based on it a new generation of nanosize
acoustic transducers including biosensors and sensors for biomedical ultrasound applications can be
developed. For biosensing application, grafting of the receptor molecules on the PNT’s is necessary
to confer them sensitivity and selectivity to the particular analytes. Scaling down to nanosize i.e. byusing single nanotube as acoustic resonator, can dramatically improve analytical performance of thesensors. Straightforward synthesis self-assembling and easy modification procedures due to thepresence of the functional groups makes PNTs an interesting alternative to the inorganic
nanostructures such as CNTs for chemical and biosensor fabrication. Moreover, a chip based on
peptide nanotubes allows different types of electrical measures to be made such as impedance or
piezoresonance, which could improve it analytical performance. Despite growing interest in PNTapplication, their integration into the microdevices and eventually µTAS remains a largely
unresolved issue.
In this work we applied a new technology of PNT manipulation in an ac electric field. Using thismethod PNTs can be oriented to lay on the substrate between two gold electrode. Morphology andresonance behaviour of the nanotubes deposited on the dielectrophoresis microchip werecharacterized using SEM, AFM and PFM. Further, the performance of peptide nanotubes forpiezoelectric devices is analyzed in terms of their figures of merit for various applications.

329

A.L.Kholkin et al, “Strong piezoepiezoelectricity in bioinspired peptide nanotubes”. ACS Nano 4, 610, 2010

ISAF1-K3-3 _____________________________________________________________________________________________________________________PROBING COUPLED METAL-INSULATOR AND FERROIC TRANSITIONS FROM THE
ATOMISTIC TO MESOSCOPIC SCALES: IN-SITU PLD-STM STUDY
S.V. Kalinin, A. Tselev, Z. Gai, P. Maksymovych, M. Pan, and A.P. Baddorf
sergei2@ornl.gov
Oak Ridge National Laboratory, Oak Ridge, TN 37831
The coupling between electronic and ferroic behaviors has emerged as one of the most intriguing aspects ofcondensed matter physics, with examples including phase separation in complex oxides, metal-insulatortransitions in ferroelastic oxides, and complex electronic ordering patterns in superconducting and chargedensity wave materials. Both structural and electronic aspects of these behaviors are currently of interest forenergy generation and storage applications, and are uniquely accessible through high-resolution probe-based
studies. In this presentation, I will discuss several examples of high-resolution studies of the mechanisms ofcoupled electronic (metal-insulator, superconductive) and ferroic (ferro- and antiferroelastic, ferro andantiferroelectric) transitions from atomistic to mesoscopic scales enabled by combination of the in-situ
Pulsed Laser Deposition growth with atomic resolution Scanning Tunneling Microscopy and Spectroscopy.
Notably, for oxide these studies should explicitly address the possibility of vacancy dynamics and vacancy
coupling to measured physical phenomena. On the mesoscopic level, we explored experimental signatures ofthe bias- and strain induced vacancy dynamics in simple oxides including NiO through the high-dimensionalscanning probe microscopy measurements, and developed associated Ginzburg-Landau based theoreticaldescription. On the atomistic level, we extended the applicability of local crystallographic mapping toscanning tunneling microscopy data, allowing for mapping surface electrochemistry and order parameterfields on the atomic level in manganites, ruthenates, and high-temperature superconductors.
This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences (BES),
Materials Sciences and Engineering Division (SVK, PM, AT). ZG, MP and AB are supported by the Center
for Nanophase Materials Sciences which is sponsored by the Scientific User Facilities Division, Office ofBasic Energy Sciences, U.S. Department of Energy

ISAF1-K3-4 _____________________________________________________________________________________________________________________SKIN LAYERS ON MULTIFERROIC AND RELAXOR SINGLECRYSTALS
Neus Domingo,1 Jose Santisso,1 Gustau Catalan2,3
Oxide Nanoelectronics Group, Centre d’Investigació en Nanociència i Nanotecnologia, CIN2
(CSIC-ICN), Bellaterra, Spain
2
Oxide Nanoelectronics Group, Institut Català de Nanociència (ICN), Bellaterra, Spain
3
Institut Catala de Recerca i Estudis Avançats, (ICREA) Catalunya, Spain.
Email: neus.domingo@cin2.es
Skin effects are commonly observed in different types of single crystals: in regions close to thesurface, structural and functional properties different from that of the bulk can be observed. In thispresentation we want to overview the main features that characterize skin layers observed indifferent types of ferroelectric single crystals, from multiferroic materials such as BiFeO3 todifferent examples of relaxors such as PZN-PT.
1

Skin layer of BiFeO3 has been analyzed with different techniques from surface impedance andgrazing incidence X-ray diffraction to atomic force based techniques such as Piezoresponse ForceMicroscopy (PFM). It has been demonstrated that the skin shows a specific phase transition at T* 
275 ºC below the bulk transition temperature, characteristic dielectric properties and a complex
distribution of near-surface ferroelectric nanodomains that organize in a hierarchical metastructure
on top of the existing bulk domains.
On the other hand, morphotropic phase boundary
relaxors have been intensely studied for the last
15 years, on account of their giant
electromechanical performance. The relaxation
dynamics have traditionally been linked to theexistence of both chemical and structural
heterogeneity on a nanoscopic scale, with random
bonds and random fields disrupting a true longrange ferroelectric ordering. For reasons that areas yet not understood, relaxor ferroelectrics
display fairly thick surface layers (“skin layers”)
with different symmetry compared to bulk. Thus,in morphotropic phase boundary materials suchas PMN-PT, X-ray diffraction indicates that the Fig. 100: Phase PFM image of the skin layer ofsymmetry of the surface layer is instead PZN-PT measured at room temperature.
rhombohedral,andinvestigations
bypiezoresponse force microscopy show a labyrinthine 180 degree domain structure with out-of-plane
polarization. In this presentation, we will show in closer detail the surface layer of these materials,
and in particular the temperature dependence of its properties. Using a combination of temperaturedependent Piezoresponse force microscopy (PFM) and grazing incidence X-ray (XRD) we
confirmed that the skin layer indeed has different symmetry and different domain structure ascompared to the bulk, surviving to temperatures hundreds of degrees above the bulk, corroboratingthat skin layers have their own phase diagram quite independent from that of bulk.

ISAF1-K3-5 _____________________________________________________________________________________________________________________

Experimental and theoretical methods of accessing local
correlations in modern ferroelectric materials
Marek Paściak1, T. Richard Welberry2, Jiri Hlinka1
1Institute of Physics, The Academy of Sciences of the Czech Republic, Prague, Czech Republic2
Research School of Chemistry, Australian National University, Canberra, Australia
Email: pasciak@fzu.cz

Modern ferroelectric materials are often based on chemically disordered compounds in which local
strain and charge imbalance are used to enhance dielectric properties. Proper understanding of theatomic-scale phenomena is essential for material engineering and it constitutes a necessary first stepof any multi-scale modelling.
In our work we explore theoretical and experimental methods of accessing local structure of modern
ferroelectric materials. A lot of attention is paid to lead-based compounds such as PbMg1/3Nb2/3O3(PMN) or PbZrxTi1-xO3 (PZT) but we also include BaTiO3-related relaxor materials. As far as theexperiment is concerned we concentrate on diffraction methods which are unique in giving
opportunity of getting into nanoscale structural
correlations. These methods include xray andneutron diffuse scattering measurements for
single crystal materials and pair distributionfunction studies for ceramic/powder samples.
However, interpretation of these diffraction
experiments is very rarely straightforward.
Traditionally atomistic simulations (mostly using
the Monte Carlo method) are helpful here.
Therein, tuning of effective interactions between
atoms allows assessing correlation mechanisms. Fig. 101: Local structure of PbMg1/3Nb2/3O3 (PMN)
With ever-growing computational power more – results of a molecular dynamics simulation at
sophisticated models, e.g. ab-initio based inter- 10 K. (a) arrangements of atoms in a B-site centeredatomic potentials, can be used for direct perovskite unit cell with a characteristic disorderedinterpretation of diffuse scattering330. Working in distribution of lead positions, (b) dipole
arrangement on the xy plane of the simulated
a real space with trustworthy potentials has also
crystal.
an advantage of providing a direct access intomechanisms that drive the relationship between chemical disorder/short-range order and polar
correlations.
The other important issue is related to distinguishing dynamic and static phenomena. While neutron
inelastic scattering can give some insight into the time-scale of short-range ordered clusters(nanoregions), molecular dynamics method (either classical or first principles) is suitable for330

M. Paściak, T. R. Welberry, J. Kulda, M. Kempa and J. Hlinka, “Polar nanoregions and diffuse scattering in
the relaxor ferroelectric PbMg1/3Nb2/3O3”, Phys. Rev. B, vol. 85, p. 224109, 2012.

interpretation of these results. Simulations at varied temperatures can help understanding
development of correlations and slowing down processes across (usually diffuse) phase transitions.

ISAF1-K3-6 _____________________________________________________________________________________________________________________

Spin-Phonon Coupling Role towards Ferroelectricity Rise in
Magnetoelectric Y-Substituted GdMnO3
R. Vilarinho1, A. Almeida1, P. B. Tavares2 and J. Agostinho Moreira1
1

IFIMUP and IN-Institute of Nanoscience and Nanotechnology, and Departamento de Física e
Astronomia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal.
2
Centro de Química, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal.
Email: ruivilarinhosilva@gmail.com

Magnetoelectric multiferroics are very interesting materials, as they exhibit ferromagnetism andferroelectricity coupled together, opening the possibility of new technological devices. However,these kinds of materials are very scarce. Among the magnetoelectric compounds, someorthorhombic rare-earth manganites, with distorted perovskite structures, and general formulaRMnO3, with R = Eu to Dy, are the most studiedxxvi. In these compounds, ferroelectricity has been
comprehended on the ground of the inverse Dzyaloshinskii-Moriya model, where the modulated
spin ordering induces lattice deformations, yielding electric polarization. In this scope, the interplay
between the magnetic and polar degrees of freedom involves spin-lattice and thus spin-phonon
coupling. Spin-phonon coupling has been studied in several magnetoelectric materials by using both
Raman and infrared spectroscopies and have confirmed the significant role played by the
Dzyaloshinskii-Moriya mechanism in determining their phase diagramsxxvii. Although an extensive
study, the origin of magnetically induced ferroelectricity is not yet fully understood.
In this work, we present a detailed characterization of magnetic, dielectric and thermodynamic
properties, as well as the study of lattice dynamics at low temperatures of the system Gd1-xYxMnO3,
with x = 0 to 0.4. The substitution of the Gd3+ ion by the smaller Y3+ ion enables us to control theunit cell distortion, involving a complex set of geometrical changes, where two of them stand-up:
Jahn-Teller and tilt of MnO6 octahedra, occurring alternately in opposite directions along the
crystallographic c-direction, if Pbnm notation is used. These distortions, characterized by the bonds
connecting Mn3+ and octahedral oxygen ions, highly depend on the effective size of the R ion (rR).
The great advantage of this solid solution is that by increasing the substitution ratio only the effectof geometrical mechanisms, and thus the magnetic exchange integrals, is expected to influence its
phase diagram, enabling to establish the role of spin-phonon coupling in tailoring the nature andnumber of different phasesxxviii.
The magnetoelectric effect is evidenced by the anomalous behavior of the dielectric constantthrough the magnetic phase transition. Inversion polarization measurements are in favor for nonlinear polar effects, which yields the emergence of ferroelectricity induced by A-site substitution
and magnetic field. The temperature dependence of the Raman active modes of the MnO6 units hasrevealed either a positive or negative shift regarding the pure anharmonic temperature dependenceof the phonon frequency, which can be understood in terms of competitive ferromagnetic andantiferromagnetic interactions, strongly dependent on Y concentration. The relation between spinspin correlation function and anomalous Raman mode frequency behavior is evidenced enabling thedetermination of the spin-phonon coupling parameter.

Electrocaloric Materials and Devices
CLUB A
Thursday, July 25 2013, 10:30 am - 12:00 pm
Chair:

Stanislav Kamba
Institute of Physics, Academy of Sciences of the Czech RepublicISAF4-L1-1 _____________________________________________________________________________________________________________________

Influence of Electrical and Mechanical Boundary Conditions on
the Electrocaloric Properties of Ferroelectric Thin Films
George A. Rossetti Jr.1, S. Pamir Alpay1
1

Materials Science and Engineering, University of Connecticut, Storrs, CT, USA
Email: rossetti@ims.uconn.edu

The electrothermal (electrocaloric and pyroelectric) properties of ferroelectric thin films have many
applications in active solid-state cooling and infrared sensing devices. The electrocaloric andpyroelectric responses describe converse effects, wherein an adiabatic change in temperature occurs
in response to a change in applied electric field, or a change in the dielectric displacement occurs in
response to a change in temperature. It has been demonstrated that some thin-film ferroelectrics can
produce much larger electrothermal responses than their bulk counterparts. For on-chip
applications, thin film ferroelectrics must be deposited on IC compatible substrates. The growth offerroelectric films typically employs sputtering or metal-organic solution deposition techniques andthe resultant ferroelectric film is usually polycrystalline. For such films, in-plane strains arise fromthermal stresses due to the thermal expansion mismatch between the film and the substrate, and also
from the self-strain of the paraelectric-ferroelectric phase transformation. A thermodynamic
methodology is described and used to investigate the electrocaloric response of ferroelectric thinfilms under the influence of differing electrical and mechanical boundary conditions including bias
and driving field, lateral clamping andmisfit strain, and thermal stresses. The
calculations are performed on perovskite
ferroelectric materials including BaTiO3,
PbTiO3, and the incipient ferroelectric
SrTiO3. The results show how electricaland mechanical boundary conditions
modify the electrocaloric properties for agiven material composition. It is further
shown that thermal stresses that develop
during processing can have a significant
influence on the electrothermal propertiesof polycrystalline ferroelectric films on
IC-friendly
substrates.
Therefore,
appropriate choices of the ferroelectric Fig. 102. Adiabatic temperature change, T, inmaterial, substrate, growth or annealing bu lk sin gle cryst al and (001 ) textu redtemperature, and electrode configuration polycrystalline BaTiO3 on Si as a function of
can be used to control the electrocaloric temperature at different growth temperatures,TG, under a bias field Ea=50 kV/cm and field
response.
c h a n g e Δ E = 1 2 0 k V / c m .

ISAF4-L1-2 _____________________________________________________________________________________________________________________The electrocaloric efficiency of ceramic and polymer films
E.Defay1,2, S. Crossley2, S. Kar-Narayan2, X. Moya2 and N. D. Mathur2
1
CEA, LETI, Minatec Campus, Grenoble, France
2
Department of Materials Science, University of Cambridge, Cambridge, UK
Email: emmanuel.defay@cea.fr; ndm12@cam.ac.uk
Voltage-driven thermal changes known as electrocaloric (EC) effects are large in ferroelectric thinfilms near the Curie temperature, where entropic electrical phase transitions may be reversibly
driven by electric fields E that approach the high breakdown fields generically associated with thinfilms. The thermal changes in a single film are small, but macroscopic assemblies of ferroelectricfilms in the multilayer capacitor geometry have been proposed for cheap, environmentally friendly
and energy efficient cooling applications. However, candidate EC materials have hitherto only been
analysed in terms of EC performance, i.e. the change in isothermal entropy S, the isothermal heatQ, and the change in adiabatic temperature T. Surprisingly, the corresponding electrical work W
that is done when charging and discharging the host EC capacitors has been neglected. Therefore
we introduce here electrocaloric efficiency  to describe the ratio of reversible electrocaloric heat toreversible electrical work under isothermal conditions1. This figure of merit permits a comparisonof EC materials that does not depend on details of any refrigeration cycle, i.e. the type of cycle, thehot and cold temperatures of the EC material, and the sink and load temperatures. We investigate indetail 350 nm thick films of the prototypical electrocaloric ceramic PbZr0.95Ti0.05O3 (PZT) with Pt
electrodes2, and 0.4 - 2.0 µm-thick films of the prototypical electrocaloric polymer poly(vinylidene
fluoride-trifluoroethylene) (55/45 mol %) [P(VDF TrFE)] with Al electrodes3. For these films near
their respective Curie temperatures, the electrical data that were used to predict large and nominally
reversible EC effects, are used here to calculate the nominally reversible electrical work, yielding = 3.0 for the ceramic and  = 7.5 for the polymer. We subsequently use the Landau theory of phasetransitions to reveal the presence of non electrocaloric edge layers that increase the work, and toreveal the role of a previously observed complexity in the polymer phase transition of ref. 3. In awider study, we find that ceramic and polymer films possess overlapping efficiencies, and therefore
both classes of material may be attractive for applications despite previous indications. Moregenerally, optimising  should in future guide the selection of electrocaloric, elastocaloric andmagnetocaloric materials for novel cooling devices that are energy efficient.
1

E. Defay, S. Crossley, S. Kar-Narayan, X. Moya and N. D. Mathur, Adv. Mat., 2013

2

A. S. Mischenko, Q. Zhang, J. F. Scott, R. W. Whatmore and N. D. Mathur, Science, 2006, 311, 1270.

3

B. Neese, B. Chu, S.-G. Lu, Y. Wang, E. Furman and Q. M. Zhang, Science, 2008, 321, 821.

ISAF4-L1-3 _____________________________________________________________________________________________________________________High Temperature Piezoelectric and Electrocaloric Metrology
P. M. Weaver1, P. Woolliams1, T. Correia1, G. Bartl3, T. Quast3, T. Stevenson4, J. Hameury5, P.
Klapetek6, M. Shpak7, T. Schmitz-Kempen81

National Physical Laboratory, Teddington, UK
Department, Institution/Company, City, State/Country3
Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany
4
Institute for Materials Research, University of Leeds, Leeds, UK
5
Laboratoire National de Métrologie et d’Essais (LNE), Trappes / France
6
Department, Institution/Company, City, State/Country
7
Thermal and Mass Metrology, Centre for Metrology and Accreditation, Espoo, Finland
8aixACCT Systems GmbH, Aachen, Germany
2

Email: paul.weaver@npl.co.uk
New piezoelectric materials capable of operating at elevated temperatures, are being developed toreduce energy consumption and improve efficiency and reliability in automotive, energy, process,electronics and medical industries. Degradation of material and electrical properties at hightemperature means that these applications are typically limited to operating below 200 °C. The
electrocaloric effect in ferroelectrics has strong potential as an efficient cooler for computer chips
and domestic and industrial refrigeration. The ferroelectric materials used in these applications
exhibit strong coupling between electrical, thermal and mechanical properties. Direct coupling
provides the technological useful properties of piezoelectric and electrocaloric effects, but crosscoupling also needs to be taken into account. Examples include the dependence of thermal expansion(thermoelastic effect) on electrical conditions, and stress effects on electrocaloric cooling.
This presentation describes a pan-European effort to develop new metrological approaches to thechallenges of measuring multifunctional coupling at temperatures up to 1000 °C. Non-contact
approaches to measuring coupled piezoelectric and thermoelastic strain and direct electrocaloric
measurements are described. To unravel the thermoelastic and electromechanical couplings, PTB
conducts high-accuracy piezoelectric strain measurements within a temperature range from room
temperature to 200°C. This is achieved by full-optical-field multi-wavelength interferometry. To
extend the capabilities of the current setup, a heatable sample environment with high-voltage
functionality is being developed. For aixACCT Systems as an industry partner within this project,extending the test capabilities of their commercial piezoelectric test systems to high temperatures is amain focus as well as standardization of piezoelectric testing under temperature and creating stablereference materials and samples for metrology. Initial results on high TC materials of current
technological interest, based on bismuth ferrite perovskite systems, are described.
This work has been performed in the framework of the joint research project “Metrology of electrothermal coupling for new functional materials technology”, which is supported by the European
Metrology Research Programme (EMRP), jointly funded by the EMRP participating countries
within EURAMET and the European Union.

ISAF4-L1-4 _____________________________________________________________________________________________________________________

Requirements to (Ba,Ca)(Zr,Ti)O3 electrocaloric materials
Gunnar Suchaneck, Gerald Gerlach
Solid State Electronics Lab, TU Dresden, 01062 Dresden, Germany
Email: Gunnar.Suchaneck@tu-dresden.deHeating and cooling are major power consumption technologies. For instance, the demand forheating and cooling is about half of the total energy demand in Europe, most of which is needed at
low to medium temperatures (up to 250°C). Lead-free (Ba,Ca)(Zr,Ti)O3 electrocaloric (EC) devices
based on a reverse Brayton cycle (adiabatic polarization heating the sample, heat rejection to thethermal bath, adiabatic depolarization cooling the sample and heat absorption from the device) are
expected to provide cooling power densities of 30 to 300 W/cm2.
The adiabatic temperature change above the Curie temperature TC is determined mainly by theapplied electric field which hence is a key parameter of an EC device. An approach to reach highbreakdown field strengths of films in a bulk material is to use a multilayer capacitor structure withinterdigitated metallic electrodes. They do not require a substrate, provide an efficient heat transfer
between the EC elements and avoid arcing as a frequent failure mechanism. The main requirements
to the EC layers are: (i) a maximum temperature coefficient d/dT of dielectric permittivity (> 100K-1) (ii) TC just below the operation temperature range, (iii) large dielectric strength (> 100 V/µm)
and low electrical aging, (iv) low dielectric losses (< 2%), (v) sufficient thermal conductivity andlarge heat capacity of one EC element, and (vi), a positive slope of d/dT, i.e., d2/dT2 > 0, in orderto prevent EC element heating during the successive thermodynamic cycles.
The ternary BaTiO3-BaZrO3-CaTiO3 phase
diagram shows different regions of dielectric
behavior (Fig. 1). The maximum d/dT above TC
appears when the three phase transitions of
BaTiO3 (rhombohedral => orthorhombic =>tetragonal => cubic) occur simultaneously at thesame temperature. This coincides also with the
known tricritical triple points of the cubicparaelectricphase,
theferroelectricrhombohedral and tetragonal phases in
pseudobinaryBa(Ti1-xZrx)O3-(Ba1-yCay)TiO3
solid solutions.
This paper discusses the electric fielddependence of the EC effect, the influence of theferroelectric-paraelectric
phasetransition
diffuseness on EC device operation as well as theinfluence of film composition, stoichiometry andFig. 103: BaTiO3-BaZrO3-CaTiO3 ternary phase
acceptor doping on materials aging.

diagram, zones of different dielectric behavior331,
tricritical points of Ba(Ti1-xZrx)O3-(Ba1-yCay)TiO3
331
solid tosolutionsand statediffusenessof theJ. Ravez, A. Simon, “ Spontaneous transition from relaxor
ferroelectricin new coefficientlead-free perovskite
phase transition to the paraelectric state.
ceramics”, Ferroelectrics, vol. 240, p. 1579-1586, 2000.

ISAF4-L1-5 _____________________________________________________________________________________________________________________

Scaling Laws for the Electrocaloric Effect in Alkaline Earth
Titanates
A. Berenov1, F. Le Goupil1, N. Alford1
1

Department of Materials, Imperial College London, London, UK
Email: a.berenov@imperial.ac.uk

Recently, solid state refrigeration based on the electrocaloric effect, EC, has attracted a great deal ofattention due to the easy generation of large electric fields, high efficiency and relatively low cation
variance332) in the perovskite structure on the EC behavior was evaluated.
0.3

1.0

0.4

Ba0.74Sr0.12Ca0.15TiO3

0.2

Ba0.78Ca0.22TiO3

S

pk
mol

0.1

0.0
60

1.0

Ba0.69Sr0.24Ca0.07TiO3

Ba0.8Sr0.2TiO3

Tr1

TC
70

80

90

100 1100.8

Series B
Ba0.6Sr0.2Ca0.2TiO3

0.6

r/max

0.6

Series A
Ba0.6Sr0.35TiO3

Spk
mol

Smol (J mol-1 K-1)

0.8

Smol/Spkmol

A series of perovskites with the general formulaBa1-x-ySrxCayTiO3 (0≤x≤0.35, 0≤y≤0.22) wereprepared. The dependence of TC on both theaverage ionic radii and the cation variance wasestablished. The studied specimens showed
typical ferroelectric behavior with low leakage
current.

0.4

T (°C)
Molar entropy change, ΔSmol, during the EC
0.2
0.2
response was measured both directly by themodified DSC technique and indirectly from the
0.0
0.0
P-E loops. A very good agreement between the
-4
-2
0
2
4
(T-TC)/(Tr1-TC)
values of ΔSmol measured by both techniques was
obtained. The EC performance of the studied
ceramics was evaluated as a function of Fig. 104: Universal curves of the temperaturetemperature, T, and applied electric field, E. The dependence of ΔSmol for studied (Ba,Sr,Ca)TiO3
maximum ΔSmol was observed close to the TC and samples when plotted on reduced axis. Inset showsincreased with the TC. The EC response depended EC data for Ba0.74Sr0.12Ca0.15TiO3 at 10 kV/cm.
on the applied electric field as ΔSmol~En. The
temperature dependence of n was similar to the one observed in magnetocaloric materials.
Universal curves of the temperature dependence of ΔSmol (Fig 1) and n were constructed by analogy
with magnetocaloric materials333. The parameters of the universal curves depended on the values ofTC and allowed complete description of the EC effect in (Ba,Sr,Ca)TiO3 perovskites. The
temperature changes observed in the studied alkaline earth titanates (e.g. 0.92 K at 20 °C and 44
kV/cm for Ba0.65Sr0.35TiO3) suggested that they are very promising EC materials which areenvironmentally friendly alternatives to current lead containing EC compounds (e.g. PMN-PT334).

332

L.M. Rodriguez-Martinez et al., “Cation disorder and size effects in magnetoresistive manganese oxide perovskites”,
Phys. Rev. B, Vol. 54, p. R15622-R 15625, 1996.
333

V. Franco et al., “Scaling laws for the magnetocaloric effect in second order phase transitions: From physics toapplications for the characterization of materials”, Int. J. Refrig.,. Vol. 33, p. 465- 473, 2010.
334

G. Sebald et al., “Electrocaloric and pyroelectric properties of 0.75Pb(Mg 1/3Nb2/3)O3--0.25PbTiO3 single crystals”, J.
Appl. Phys., Vol. 12, p. 124112, 2006

Modeling: LGD, Phase-Field,...
CLUB B
Thursday, July 25 2013, 10:30 am - 12:00 pm
Chair:To Be Announced

ISAF1-L2-1 _____________________________________________________________________________________________________________________

Thermodynamic Theory and Phase Field Model of Domain
Structures in Ferroelectric Thin Layers and Bi-Layers
Andrei Artemev1 and Alexander Roytburd2
1

2

Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada
Department of Materials Science and Engineering, University of Maryland, College Park, USA
Email: aartemev@connect.carleton.ca

The domain structure in ferroelectric thin layers and bi-layer films formed by weak and strong
ferroelectrics or by a ferroelectric and a dielectric was studied using the homogenizedthermodynamics model and phase field simulations. The thermodynamic analysis predicted that theincrease in the weak ferroelectric or dielectric layer thickness would result in the changes in thecritical field of the single-domain (SD) to polydomain (PD) transition from negative to positive, andthe hysteresis loop shape from simple rectangular to composite, consisting of two offset triangularloops describing the PD↔SD transition hysteresis and a central loop describing the hysteresis of the
PD state switching, with the central loop reduced to a zero-hysteresis P(E) curve in dielectricferroelectric bilayers, and in the reduction in the remnant polarization and coercive field.
The phase field simulations were performed for the a) bilayers consisting of either strong
ferroelectric BaTiO3 and weak ferroelectric Ba0.3Sr(1-0.3)TiO3 or strong ferroelectric BaTiO3 anddielectric Ba0.2Sr(1-0.2)TiO3 with a high dielectric constant (=950), and b) thin layers of BaTiO3 witha low dielectric constant (=8) deadlayers. In all simulations the clamping effect of the SrTiO3
substrate was introduced using the renormalization of the Landau-Ginsburg-Devonshire free energy
density function. The simulations were performed for the bilayers with different a) ratios of thelayer thickness and b) absolute thickness of the BaTiO3 ferroelectric layer. In all simulations theclamping effect of the substrate resulted in the 180o domain structure formation. 1D and 3D
ferroelectric models produced significantly different results; hence, it is important to use a full 3D
ferroelectric model even for the simulation of films containing only 180o c domains due to clamping
or poling effects.
The phase field simulations demonstrated that the stripe (or labyrinth) domain structure is produced
in all films by the transformation from a paraelectric state at zero applied field conditions. The
domain structure completely penetrates a weak ferroelectric or dielectric layer with a high dielectric
constant; however, there is almost no penetration into low dielectric constant deadlayers. Thisdomain structure transforms into columnar domains during poling, after which the PD state changes
into the SD state. The P(E) loops obtained by the phase field modeling for strong ferroelectric-weakferroelectric bilayers were similar to those predicted by the thermodynamic model. However, theloops obtained for strong ferroelectric - dielectric bilayers differed from the thermodynamic
predictions. As a result of a specific behavior of the columnar domain structure produced by the SD
to PD transition in the reversing applied field, they had a central loop with a large hysteresis effectinstead of a zero-hysteresis curve connecting two offset triangular loops. Phase field modelingdemonstrated the possibility of the hysteresis effect of the stripe to columnar domain morphology
transition appearing as a result of a repulsive interaction between columnar domains. The
simulation results and thermodynamic analysis demonstrate that in thin films the SD to PD

transition can go through the spinodal decomposition of the SD state, while in thick films it should
develop by the nucleation and growth mechanism.

ISAF1-L2-2 _____________________________________________________________________________________________________________________

Tracking the origin of dielectric response of simple domain
patterns in BaTiO3
P. Marton, I. Rychetský, A. Klíč, and J. Hlinka
Department of dielectrics, Institute of Physics, Acad. Sci. Czech Rep., Praha, Czech Republic
Email: marton@fzu.cz

Domain walls in ferroelectric materials are known to have significant impact on theelectromechanical response to an external loading. The exact role of domain walls in dielectric
response is, nevertheless, complex and not yet fully understood. A domain wall can sweep
macroscopically through the crystal, allowing polarization reversal at moderate electric-field
amplitudes well below the coercive field of a monodomain sample. In reality, however, the mobilityof walls is usually strongly limited, e.g. due to different types of pinning.
Even if macroscopically immobile, walls can still significantly alter the dielectric response. The
effect may originate e.g. in domain-wall deflection from its original position, broadening, and otherrecently suggested mechanisms335336337338. There are as well simple situations where a domain wall
only acts as an interface between the surrounding domains, and the domain geometry itself and its
relation to the acting field are dominant.
In this contribution we provide analysis of a frequency-dependent dielectric response of several
important domain patterns appearing in the tetragonal phase of prototype ferroelectric material
BaTiO3. We make distinction between the response from a domain wall, and response from domain
structure as such. Combination of the analytical algebraic derivations and numerical simulations
within the Ginzburg-Landau-Devonshire phenomenological theory, complemented with the Finiteelement-method339 simulations of domain configuration with zero-thickness domain walls is
employed.

335

Rao and Wang, “Domain wall broadening mechanism for domain size effect of enhanced piezoelectricity incrystallographically engineered ferroelectric single crystals ” Appl. Phys. Lett., vol. 90, p. 041915, 2007.
336

J. Hlinka, P. Ondrejkovic, and P. Marton, “The piezoelectric response of nanotwinned BaTiO3 ”,
Nanotechnology, vol. 20, p. 105709 , 2009.
337
V. Stepkova, P. Marton, and J. Hlinka, ”Stress-induced phase transition in
ferroelectric domain walls of BaTiO3”, J. Phys.: Condens. Matter, vol. 24, p. 212201, 2013.
338
T. Sluka, A. K. Taganstev, D. Damjanovic, M. Gureev, and N. Setter, “Enhanced electromechanical responseof ferroelectrics due to charged domain walls”, Nature Communications, vol. 3, p. 748, 2012.
339

A. Klic and I. Rychetsky, “Dielectric Response of Arbitrary-Shaped Clusters Studied by the Finite Element
Method”, Ferroelectrics, vol. 427, p. 143, 2012.

ISAF1-L2-3 _____________________________________________________________________________________________________________________

Nonlinear Extrinsic Permittivity and Piezoelectricity in Lead
Titanate due to Domain Walls Pinning
Pavel Mokrý1, Tomáš Sluka2, Alexander K. Tagantsev2
1

Institute of Mechatronics and Computer Engineering, Technical University of Liberec
Studentská 2, Liberec, Czech Republic, CZ-46117
2
Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL) Lausanne
CH-1015 Lausanne, Switzerland
Email: pavel.mokry@tul.cz

It is known that the restoring force acting on a disequilibrated domain wall is the key factor which
controls macroscopic values of the extrinsic (i.e. domain wall) contributions to permittivity andpiezoelectricity. Considering the bulk properties of perovskites, the main contribution to therestoring force comes from the interaction of domain walls with so called pinning centers (PCs)such as crystal lattice point defects or dislocations. It is clear that the number of PCs can beessentially controlled by composition of the material and the processing technology. In addition,
there exist two types of domain wall movement between PCs: First, the planar wall passes throughthe PC and, second, the domain wall bends between PCs. It has been shown by analyticalmodeling340 that each physical phenomenon that controls the restoring force on the domain wall
introduces qualitatively different macroscopic features to the nonlinear dielectric and piezoelectric
response. These features can be identified in experimental data.
The aforementioned issue has motivated the work presented in this paper. We have developed athermodynamic Phase-Field-Model of 180° and 90° domain walls interacting with a PC (see Fig. 1)
in lead titanate. We have performed a series of massive numerical computations, which resulted inmacroscopic values of piezoelectric coefficients. The results of our computations indicated that boththeextrinsic
permittivity
andpiezoelectricity are generally nonlinear.
We computed the linear and nonlinear
contribution to the extrinsic permittivity
and piezoelectricity as a function of PCsconcentration. The results indicated a
cubic relationship between linear andnonlinear permittivity for this type of
extrinsic contribution, which is quite
different from that of the latticecontribution derived from Landau theory. Fig. 105: Visualization of the 90° domain wall in leadtitanate using Phase-Field-Model. When an external electric
These results are in a good agreement
field is applied in the vertical direction, the domain wall iswith a simple but rather general shifted. The domain wall shift contributes to thethermodynamic model. We propose that piezoelectricity.
such results can be used for the analysisof experimental data and for the characterization of lead-free ceramics and single crystals.
340

P. Mokrý, “A method to study ageing of polydomain ferroelectrics using measurements of nonlinear permittivity”,
Ferroelectrics, vol. 375, p. 40-55, 2008.

ISAF1-L2-4 _____________________________________________________________________________________________________________________

Influence of uniaxial stress on the ferroelectric-to-paraelectric phasetransition in barium titanate
Florian Schader1, Emil Aulbach1, George A. Rossetti, Jr.2, and Kyle G. Webber1
1

Institute of Materials Science, Technische Universität Darmstadt, 64287, Darmstadt, Germany
2
Department of Materials Science and Engineering and Institute of Materials Science,
University of Connecticut, Storrs, Connecticut 06269, USA
Email: schader@ceramics.tu-darmstadt.de

The perovskite compound barium titanate (BaTiO3) is an important material for discrete andmultilayer capacitors because of its high relative dielectric permittivity. As an end member in leadfree ferroelectrics solutions, such as (1-x-y)(Bi1/2Na1/2)TiO3–xBaTiO3–y(K0.5Na0.5)NbO3, BaTiO3
has received renewed interest. These lead-free compositions can display large unipolar strains,
attractive for actuator applications. In the mechanically unloaded state, BaTiO3 undergoes threewell-known first order polymorphic phase transitions on cooling from high temperature, cubic (C) tetragonal (T) orthorhombic (O) rhombohedral (R). The ferroelectric-to-paraelectric (FEPE) and inter-ferroelectric transition temperatures have been shown to depend on a number of
extrinsic factors, including grain size, dopants, and the quality and form (single crystal,polycrystalline) of the specimen investigated, in addition to the electrical and mechanical boundary
conditions.
In order to better understand the influenceof mechanical boundary conditions on phasetransitions in perovskite ferroelectrics, the effect ofuniaxial compressive stress on unpoled <001>Coriented single crystal and polycrystalline BaTiO3
has been investigated. Attention is restricted to thedielectric behavior near the C-T phase transition
where the Landau theory is asymptoticallyaccurate. The influence of uniaxial mechanical Fig. 106: Measured Curie point (square symbols)and Curie-Weiss temperature (circular symbols) for
stress on the Curie point, Curie-Weiss temperature,<001>C-oriented
singlecrystal(a)andand Curie constant were experimentally measured polycrystalline (b) BaTiO3 samples compared to(Fig. 1). The results are analyzed using a 6th order predicted values as a function of applied uniaxial
Landau polynomial, where the dependence of the compressive stress.
expansion coefficients on stress was determined. It is found that even at stresses below the coercive
stress (< 30 MPa), the quartic term in the Landau potential must display a linear dependence onstress in order to describe the experimental observations. The results are expected to be of particularimportance in modeling the behavior of ferroelectric thin films, where in-plane strains are large
enough to generate new phases and induce ferroelectricity, and for sensors, transducers, andactuators, where substantial mechanical preloads are often applied.

ISAF1-L2-5 _____________________________________________________________________________________________________________________

Finite Element based Phase Field Simulation on Interaction of
Point Defects with Domain Structure in Ferroelectrics
Baixiang Xu, Yinan Zuo
Department of Materials and Earth Science, TU Darmstadt, Darmstadt, Germany
Email: xu@mfm.tu-darmstadt.deWidely used in actuator and sensor technologies,
piezoelectric ceramics are known to experience theperformance degradation problem, which includes
e.g. aging and fatigue phenomena. It has been wellrecognized that the interaction of point defects withdomain structure plays signiﬁcant role in aging andfatigue341. However, there are various theories
regarding the exact interacting mechanisms. In thiswork numerical simulations based on a phase fieldmodel342 are conducted to investigate the inﬂuenceof point defects from two different aspects.
First of all, the free space charge may be available
by considering that ferroelectrics can besemiconducting material particularly in the presenceof defects. Simulation results, based on the phasefield model and the semiconducting theory, will beshown for ferroelectric single crystal, for instance,
BaTiO3, to demonstrate the inﬂuences of thesespace charges on the domain structures and thestability of charged domain walls. In particular, thestability of the charged domain wall will bedemonstrated by using the calculated driving forces.

Fig. 107: The calculated double loop dielectric
hysteresis, which is introduced by the defectdipole. The larger the magnitude of the defectdipole is, the wider the two loops are separated.
As the electric field returns to zero, thespontaneous polarization tends to follow thedirection of the defect polarization in favor of aminimization of total energy of the depolarization
field (domain memory effect). Thus the overall
polarization again becomes nearly zero. That may
provide an explanation to the double loop effect.

On the other hand, the defect dipoles, formed for
instance by the oxygen vacancies with the cations,may play a very diﬀerent role, as it is less mobile
than the spontaneous polarization343. Phase field
simulations by handling the defect dipole asadditional eigenpolarization can enclose the eﬀects
of the defect dipoles on the domain structure and the hysteresis, see Fig.1.
341

G. Arlt, H. Neumann, “Internal bias in ferroelectric ceramics: Origin and time dependence”, Ferroelectrics, vol. 87,
p. 109-120, 1988.
342

B.X. Xu, D. Schrade, R. Müller, D. Gross, T. Granzow, J. Rödel. Phase field simulation and experimental
investigation on electromechanical behavior of ferroelectrics. ZAMM 90 (7-8), 623- 632, 2010.
343

X. Ren, “Large electric-ﬁeld-induced strain in ferroelectric cystals by point mediated reversible domain switching”,
Nature Materials, 3 (2), 91-94, (2004).

ISAF1-L2-6 _____________________________________________________________________________________________________________________

Piezoelectric response of twinned BaTiO3
P. Ondrejkovic1, J. Hlinka1, P. Marton1, M. Guennou1, A. Tagantsev2, N. Setter2
1

2

Department of Dielectrics, Institute of Physics ASCR, Prague, Czech RepublicCeramics Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland
Email: ondrejkovic@fzu.cz

In the past decade, the high piezoelectric performance of single crystal perovskites was achieved by
the procedure called domain-engineering. For example, Wada and Tsurumi344 discovered that theboth longitudinal and transverse piezoelectric coefficients are enhanced in engineered tetragonal
BaTiO3 with a high density of 90° domain walls. This discovery was an inspiration for many phasefield simulation studies, but the mechanism is still unclear. Nowadays, the role of charged 90°
domain walls on piezoelectric properties is widely discussed345,3. However these studies require
incorporation of compensation mechanisms in phase-field models, e.g. free charges and charged
point defects.
1500
T = 298 K
domain width 22.6 nm

1000

this study
Li (2012)[100](pC/N)

500

d33

In this contribution, longitudinal piezoelectriccoefficient of a twinned ferroelectric perovskite
material with an array of partially compensated headto-head and tail-to-tail 90° domain walls has beenstudied by phase-field simulations in the frameworkof the Ginzburg-Landau-Devonshire model of
BaTiO3. Our results extend the recent phase-field
simulations of Li et al346, but also elucidate themechanism responsible for the reported enhancementof the macroscopic piezoelectric coefficient.

0-500
electric field

-1000

y
x

-1500
1.2

1.4

1.6

1.8

2.0
*

2.2

2.4

2.6

2.8

In particular, we would like to show that the Fig. 108: Effective longitudinal piezoelectric
magnitude of the compensating charge at the domain coefficient along the [100] direction as awall and the decreasing domain wall distance are function of dimensionless compensation boundboth promoting rotation of the static polarization charge (ρ*=2 stands for the full compensation)
vector within the body of adjacent domains. This in charged 90° domain walls. The inset showspolarization rotation drives the domain closer the orientation of the applied electric field withtowards transition to an orthorhombic state. The respect to studied domain structure.
proximity to this phase transition is in fact directly
related to the enhancement of the properties. Our simulations and the theory also suggest that thesame system with overcompensated charged walls may show a negative effective longitudinalcoefficient (see Fig. 1). Obtained results can be used for quantitative estimates of piezoelectric
properties of domain-engineered crystals.
S. Wada and T. Tsurumi, “Enhanced piezoelectricity of barium titanate single crystals with engineered domain
configuration”, Br. Ceram. Trans., vol. 103, p. 93-96, 2004.
344

T. Sluka, A. Tagantsev, D. Damjanovic, M. Gureev, and N. Setter, “Enhanced electromechanical response offerroelectrics due to charged domain walls ”, Nature Communications, vol. 3, p. 748, 2012.
345

Z. Li, H. Wu, and W. Cao, “Piezoelectric response of charged non-180° domain walls in ferroelectric ceramics” , J. Appl. Phys., vol. 111, p.
024106, 2012.
346

Les Bowen Memorial Session on Transducer Materials
and Devices
CLUB C
Thursday, July 25 2013, 10:30 am - 12:00 pm
Chair:

Ahmad Safari
Rutgers University

ISAF4-L3-1 _____________________________________________________________________________________________________________________

Advanced, Broadband High Performance Piezocomposite
Transducers
Brian Pazol, Timothy Mudarri, Joseph Aghia and Constance Ursch
Materials Systems Inc., Littleton, Massachusetts, USA 01460
Email: bpazol@matsysinc.com
Piezocomposites are a widely known form of piezoelectric material with proven advantages overconventional monolithic piezoelectric ceramics. Transducers made with piezocomposite (a twophased material consisting of piezoceramic and polymer) are naturally broadband (up to 80%
fractional bandwidth), have high sensitivity (up to 10 dB more than solid ceramic transducers) andcan be made in cost effective large sheets.
Materials Systems Inc. (MSI) utilizes a low cost
injection molding technique1 that allows large
areas to be made by tiling ceramic preforms (Fig.
1) into large areas at a reasonable cost. Because asignificant amount (60% to 85%) of the material
is polymer, piezocomposite transducers can bemuch lighter in weight. There is a large design
space that allows better transducer optimization
by adjusting the matrix material, active material(PZT in most cases) and the ratio of active toinactive material (volume fraction). The material Fig. 1: Photograph of a 50 mm x 50 mm injection molded
ceramic
preform
used
to
make
1-3
is conformable and can be shaped to match thepiezocomposite.
curvature of a small vehicle. Piezocomposites
have the added benefit of being extremely durable and have demonstrated survivability against
explosive shock.
A brief overview and history of MSI’s injection molding process will be presented. Several
practical transducer examples that exploit the unique properties of piezocomposite will be discussed
along with measured results. These include its ability to be curved into unusual shapes to tailor the
beam pattern for special applications, broadband response for clutter rejection and lightweight
designs for unmanned vehicles. In addition, the incorporation of second generation single crystal
materials into piezocomposites and their potential in future sonar systems will be discussed.

1

L. J. Bowen and K. W. French, “Fabrication of Piezocomposite Ceramic/Polymer Composites by Injection Molding,”
Proceedings of the 8th IEEE International Symposium on Applications of Ferroelectrics, pp. 160-163, 1992.

ISAF4-L3-2 _____________________________________________________________________________________________________________________

Effect of Electric Bias Field and Pressure on PMN-PT
Piezoelectric Single Crystals in Tonpilz transducers.
C. Granger1, JC. Debus1, A.C. Hladky-Hennion1, T. Pastureaud2, M. Doisy2 M. Pham Thi3
1

IEMN, UMR CNRS 8520, ISEN, 41 Boulevard Vauban, 59046 Lille, France

2

THALES UNDERWATER SYSTEMS, 525 Route de Dolines, Sophia Antipolis, France
3
THALES Research & Technology-France, RD 128, F-91767, Palaiseau cedex, France
Email: mai.phamthi@thalesgroup.com

PMN-PT single crystals in free standing mode exhibit high electric/piezoelectric constants and highcoupling efficiency (k33 = 0.9) but their physical constants depend strongly on temperature, stressand in particular their coercive electric field is low, about 200V/mm.
The properties of PMN PT single crystals are reversible up to 70°C before the first rhombohedraltetragonal ferroelectric transition. The depolarized field, measured from resonance spectra versus
electric bias field near 200V/mm, is consistent with the electric coercive filed. Under axial pressureof 35MPa, the depolarized field is observed near 35V/mm.
Tonpilz acoustic transducers were built with PMN-PT single crystals ring stack in a standard 33
mode. Several prototypes of transducers with different numbers of rings, head- mass materials andmechanical bias were investigated. Application of a mechanical stress or an electrical bias to single
crystal rings induces reversible phase transitions leading to better stability in the range of
mechanical stress used in Tonpilz transducer. In water, the Tonpilz projector exhibits highsensitivity (Sv=137dB) and large bandwidth between 10 and 29 kHz. With the application of anelectric bias field (135V/mm) the sensitivity increases up to 145 dB and the maximum of bandwidth
shifts toward low frequency (9kHz).

Figure: Sensitivity of Tonpilz transducer versus electric bias field (left) and power (right).

ISAF4-L3-3 _____________________________________________________________________________________________________________________

Flextensional Composite Structure with PZN-PZT Crystals forEnergy Harvesting Applications
Emre Tufekcioglu1, Aydin Dogan1
1

Department of Materials Science and Engineering
Faculty of Engineering
Anadolu University, 26555, Eskisehir, TURKEY
Email: emretufekcioglu@gmail.com

The majority of piezoelectric energy harvesting research is based on structures operating in 31(transverse) mode. For obtaining the highest level of energy from 31 mode, energy harvesters areconstructed to produce the maximum strain on the transducer material, i.e. the bimorph transducers
or monomorph patches adhered on beams. The high level of cyclic tensile stresses applied on thepiezoelectric ceramic materials cause microcracks to form inside the material and eventually failure
occurs.
In this study, the power harvesting capability of a flextensional piezo-composite structure withPZN-PZT relaxor-ferroelectric crystals as electro-active materials was evaluated. The flextensionalpiezo-composite is constantly kept under pre-stress so that the life-time of the ceramic is extended.
The energy harvesting (EH) structure consists of a cymbal electromechanical transducer and an
attached proof mass, all pre-stressed inside a rigid frame (Fig. 1). The power harvested wasevaluated by vibrating the whole structure sinusoidally with varying frequencies and measuring theelectrical outputs like voltage, current and power depending on the frequency, pre-stress, proof
mass and resistive load. The results obtained from the PZN-PZT crystals were compared with theresults obtained from soft PZT crystals.
Results show that the PH structure with PZN-PZT crystals is capable of producing 700 μW of
power at 4300 Hz and with a 5N of prestress which was measured across an electrical resistance of
100 kΩ. The measured power is more than two times the power generated by the structure with soft
PZT crystals.

Fig. 1. The Energy Harvesting Structure

ISAF4-L3-4 _____________________________________________________________________________________________________________________

Effect of Growth Conditions on Performance of
0.67BiFeO3-0.33BaTiO3 Bulk Acoustic Wave Resonators
Andrei Vorobiev1, Spartak Gevorgian1, Markus Löffler2, Eva Olsson2
1

Department of Microtechnology and Nanoscience, Chalmers University of Technology,
Gothenburg, Sweden
2
Department Applied Physics, Chalmers University of Technology, Gothenburg, Sweden
Email: andrei.vorobiev@chalmers.se
Intrinsically tunable 0.67BiFeO3-0.33BaTiO3 (BF-BT) thin film bulk acoustic wave resonators withrecord high tunability of 4.4%, electromechanical coupling coefficient of 10% and rather high Qfactor of 200, at 4 GHz, have been demonstrated recently347. In the proposed contribution wedisclose, for the first time, results of comprehensive studies of correlations between the growth
conditions, microstructure and acoustic performance of the resonators, which allowed for
optimization of the growth condition and achieving the device high performance. Particularly, it isshown that the pulsed laser deposition results in a strong asymmetric distribution of the BF-BT film
grain size, surface roughness and texturing. The rms surface roughness decreases, from 30 nm to
12 nm in the beam-plume plane, leading to significant increase in the Q-factor, from 20 up to 200(Fig. 1), due to reduction of loss associated withwave scattering at reflection from rough interface.
We explain the phenomenon by an asymmetricangular energy distribution of the plume species
caused by the laser beam-plume interaction.
The BF-BT film microstructure and surface
morphology are analyzed by means of XRD,
SEM, TEM and AFM. The observed distributionof the surface roughness is associated withvariations in the lateral grain size and shape of thegrain faceted tips due to the BF-BT film texturing.
The films grown in the area affected by the beamplume interaction are more (100) oriented in Fig. 109: Q-factors of the resonators with BF-BT
comparison with the on-axis films revealing more films grown in different positions relative to thelaser plume axis. Corresponding rms surface(110) grains.
roughness is given in brackets.

The tunable performance of the BF-BT resonators
is analyzed using the theory of dc field induced piezoelectric effect. The increase in theelectromechanical coupling coefficient, from 6% to 10%, for the (100) oriented films, is associatedwith anisotropy of the linear electrostriction coefficient. Analysis of tunabilty of the parallel
resonance frequency indicates also anisotropy of the nonlinear electrostriction coefficient. The
higher and negative nonlinear electrostriction coefficient of the (100) oriented films limits thetunabilty of the series resonance frequency.

347

A. Vorobiev, S. Gevorgian, N. Martirisyan, M. Löffler, and E. Olsson “Intrinsically tunable
0.67BiFeO3-0.33BaTiO3 thin film bulk acoustic wave resonators”, Appl. Phys. Lett., vol. 101, p. 232903 -5, 2012.

We assume that the observed effect of the laser beam-plume interaction is general and should betaken into account for any type of perovskite films grown by the pulsed laser deposition.

ISAF4-L3-5 _____________________________________________________________________________________________________________________

Hysteresis-Free High-Temperature Bimorph Lithium Niobate
Actuators Produced by Direct Bonding
Zorikhin Dmitry1,2, Baturin Ivan1,2, Mingaliev Eugene1,2, Udalov Artur1,
Akhmatkhanov Andrey1,2, Zelenovskiy Pavel1, Shur Vladimir1,2
1

Ferroelectric Laboratory, Ural Federal University, Ekaterinburg, Russia
2
Labfer Ltd., Ekaterinburg, Russia
Email: dmitry.zorikhin@labfer.usu.ru

Piezoelectric materials are widely used for precise positioning systems. Conventional piezoelectricmaterials such as PZT and lead-free ceramics have high piezoelectric coefficients but lack thetemperature stability due to low Curie temperature (Tc) and are prone to hysteresis and nonlinear
behavior. The manufacturing of linear hysteresis-free piezoelectric actuators operable in a wide
temperature range (from 77 to 900K) presents an actual technical challenge. Lithium niobate
LiNbO3 (LN) single crystals can be used in a wide temperature range (Tc = 1200oC). Bimorph
bending actuators based on bidomain LN crystals were realized by annealing close to Tc whichleads to formation of domain wall in the middle of the waferxxix,xxx. Present work is focused on the
fabrication of bimorph LN actuators using wafer-scale direct bonding.
Based on the angular dependence of the piezoelectric coefficients the optimal wafer orientations forbimorph layers were selected. Commercially available wafers with Y+128° and Y+41° (rotation of
Y+ axis towards Z+) cuts characterized by high absolute values of transverse piezoelectriccoefficients (27.3 and 17 pC/N) and low shear coefficient (7.4 and 3.8 pC/N) were used.
Direct wafer bonding with the mirrored Y and Z axes was realized by wafer cleaning, surface
activation and pre-bonding followed by annealing. To achieve particle and contamination freesurfaces mechanical cleaning with lint-free tissues followed by ultrasonic clean in DI-water for 5
min was used. Activation of bonding surfaces was achieved by rinse in RCA-1 solution(NH4OH : H2O2 : H2O, 1:1:5) at 80°C for 20 minutes followed by DI-water spin-cleaning for 5
minutes and spin-drying by N2. Such treatment resulted in reasonably clean surfaces with low
contact angle which necessary for the hydrophilic bonding. Wafers were aligned and brought
into contact. Slight pressure applied to the center had led to the spreading of the bonded area over
the whole wafer. Subsequent annealing at 300°C for 6 hours resulted in the bond strength sufficientfor the mechanical processing and actuator operation.
Actuators (10-20 mm in length and 0.5-1 mm thick) were fabricated by diamond blade cutting,polishing and sputter deposition of Ta electrodes. The displacement of the actuator during
application of driving voltage was measured by the optical interferometry and atomic force
microscopy. Linear hysteresis-free operation was demonstrated. Measured displacement values
were close to the calculated ones. Temperature stability study of the actuator performance shows nodegradation after treatment from 77 K up to 900 K. Measurements of the actuator characteristics inwide temperature range will be performed.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has
been used. The research was made possible in part by RFBR (Grants 13-02-01391-а, 11-02-91066CNRS-а), by Ministry of Education and Science (Сontract 14.513.12.0006) and with the financial
support of young scientists in terms of Ural Federal University development program.

LiTaO3 and LiNbO3
CLUB A
Thursday, July 25 2013, 02:00 pm - 03:30 pm
Chair:

Hong Wang
Xi'an Jiaotong University

ISAF1-M1-1 _____________________________________________________________________________________________________________________

Nano-Domains and Their Related Phenomena in LiTaO3 Single
Crystal Studied by Using Scanning Nonlinear Dielectric
Microscopy
Yasuo Cho1
1

Reserach Institute of Electrical Communication, Tohoku University, Sendai, Japan
Email: yasuocho@riec.tohoku.ac.jp

Scanning nonlinear dielectric microscopy is a powerful technique for measuring nano-scale domain
structure of ferroelectrics. In this paper, we present two topics, i.e. super higher order nonlinear
dielectric spectroscopy studies on congruent LiTaO3 (CLT) single crystal and conductions aroundnano-sized domain dots in CLT.
Recently, we have developed new method tomeasure a higher-order (second order) or superhigher-order (higher than second order) nonlinear
dielectric response. Nonlinear dielectric constants
(n), with n=3, 4, 5, 6,--- (in particular, we call (5),(6), ---, super-higher-order nonlinear dielectric
constants) are measured for high-resolution imaging
of ferroelectrics1. Using this method, we found themarked enhancement of nonlinear dielectric‘‘constants’’ when the applied tip–sample voltage Fig. 110: Examples of acquired images of
exceeded a particular threshold value. This is due to multidomain CLT. The amplitude of
domain nucleation activated by a huge electric field applied alternating voltage Vps were (a)under the tip. Moreover, low frequencies (less than Vp =5Vpp and (b) Vp = 15Vpp. In alla few hundred Hz) did not enhance the nonlinearity. images,the dark and bright contrasts
An effectively lower electric field caused by ion
represent the positive and negative
conduction in the sample under the tip is a possible signals, respectively. In the measurement
reason for the frequency-dependent characteristics of each Vp, the 1p–4p images wereof the enhanced nonlinearity for the applied voltage. obtained by successively switching the
Next, we measured conduction current flowing
order of demodulated signal, i.e.,thearound the nano-sized domain dots. When the size ofimages from 1p to 4p (from (3) toof nano-domain dots were relatively large ( ~100 nm
(6) signal, respectively.) were taken in
in diameter.(Fig2.(a))), a flowing current wasfrom the 1st to 4th quarters of a scanned
detected at the domain wall just like reported in BFO
area.
and PZT (But, the width of current pass is muchlarger than that of domain wall.) However,surprisingly, when the domain size gets smaller thanabout 25nm (Fig.2(b)), the current flows on thewhole area of the nano domain dot (not at the domain Fig.2: SNDM polarization images ofwall) . Schottky-like rectifying behavior of current
nano-domain dots (Left) and conduction
flow was observed even in nanometer sized domain current images on the same dots (Right).
dot. Precise experimental results will be presented in (a) Large nano-domain dot , (b) Smallthe meeting.
nano-domain dot.

1

N. Chinone et al. “Lateral resolution improvement in scanning nonlinear dielectric microscopy by measuring superhigher-order nonlinear dielectric constants”, Appl. Phys.Lett., vol. 101,213112, 2012.

ISAF1-M1-2 _____________________________________________________________________________________________________________________

Stabilizing mechanisms of strongly polar oxide surfaces: The LiNbO3 Z-cut
S. Sanna,1 S. Rode,2 R. Hölscher,1 S. Klassen,2 K. Kobayashi,3 H. Yamada,3Schmidt,1 and A. Kühnle2, ∗W.G.

(1) Lehrstuhl für Theoretische Physik, Universität Paderborn, Paderborn, Germany.
(2) Institut für Physikalische Chemie,

Johannes Gutenberg-Universität Mainz, Mainz, Germany.

(3) Department of Electronic Science and Engineering,

Kyoto University, Katsura, Nishikyo, Japan .

e-mail: simone.sanna@uni-paderborn.de

Atomic-resolution frequency modulation atomic force microscopy (FM-AFM) [1] and firstprinciples calculations [2] are employed to elucidate the mechanisms that stabilize strongly polar
oxide surfaces [3]. Using lithium niobate Z-cut as a prototypical example [4,5], it is found thatdifferent scenarios occur at different temperatures. At room temperature and for slight annealing, anadsorbate layers remains on the surface and shields the polarization surface charge. At moderatetemperatures (annealing between around 500 - 1000 K), the adsorbates desorb and an adatominduced (√7×√7) R19.1° surface reconstruction forms. The adatoms provide extra surface chargethat compensates the internal electric dipole moment. Finally, annealing at higher temperatures
leads to an atomically smooth surface with a 1×1 translational periodicity.

Fig. 1: Calculated phase diagram of the LN(0001) surface as a function of temperature and pressure[1] S. Rode, R. Hölscher, S. Sanna, S. Klassen, K. Kobayashi, H. Yamada, W.G. Schmidt and A. Kühnle, Phys.
Rev. B 86, 075468 (2012).
[2] S. Sanna, R. Hölscher and W. G. Schmidt, Phys. Rev. B 86, 205407 (2012).
[3] Goniakowski, F. Finocchi, and C. Noguera, Rep. Prog. Phys. 71, 016501 (2008).
[4] S. Sanna and W. G. Schmidt, Phys Rev B 81, 214116 (2010).

[5] S. V. Levchenko and A. M. Rappe, Phys. Rev. Lett. 100 (2008).

ISAF1-M1-3 _____________________________________________________________________________________________________________________

Strain and chemical engineering in LiNbO3 and LiTaO3 thin
films
A.Bartasyte1, V. Plausinaitiene2, A. Abrutis2, S. Margueron3, T. Murauskas2, P. Boulet1, V.
Kubilius2, Z. Saltyte2
1

Institute Jean Lamour, (UMR 7198) CNRS – Lorraine University, Nancy, France
University of Vilnius, Dept. of General and Inorganic Chemistry, Vilnius, Lithuania
3
Laboratoire Matériaux Optiques, Photonique et Systèmes, EA 4423, Lorraine University andSupelec, Metz, France
2

Email: ausrine.bartasyte@univ-lorraine.fr
LiNbO3 and LiTaO3 are the two of the most important crystals, being the equivalent in the field of
optics, nonlinear optics and optoelectronics to silicon in electronics. Optically isotropic ferroelectricmaterials (for thermal sensing) or piezoelectric materials with reduced temperature coefficient of
frequency (for acoustic delays lines/resonators) were obtained by chemical engineering of LiNbO3and LiTaO3348,349. Thus, the studies about epitaxial ferroelectric LiNbO3 and LiTaO3 thin films areof great interest because of their potential application as miniaturized and integrated elements instatic random access memories, high dielectric constant capacitors, acoustic delay lines, resonators,
pyroelectric sensors, and optical waveguides. Although LiNbO3 and LiTaO3 films have been
fabricated by different techniques, many electrical and electro-optical properties reported are notcomparable for those of LiNbO3 and LiTaO3 single-crystals. The growth of high quality
LiNbO3/LiTaO3 films is far from being a routine due to a difficulty to estimate the phasecomposition and Li stoichiometry. Thus, the deposited films are hardly reproducible, often contain
undesirable phases (for example, LiNb3O8 or Li3NbO4) or are stoichiometrically inhomogeneous.
This inhibits the applications of the materials in the thin film form.
In this work, the physical and structural properties of LiTaO3 and LiNbO3 thin films were tuned bychanging their chemical composition and strain state. The possibility to change by several times thethermal expansion of LiNbO3/LiTaO3 thin films by applying biaxial strain was observed. This
opens new avenues for temperature compensated devices350. Moreover, the indirect methods, used
to estimate Li concentration in the single crystals, cannot be applied directly due to the presence ofstrain, size effects or other defects in the films, which influences also the structural, optical andother physical properties. Thus, the indirect method for estimation of nonstoichiometry of LiNbO3and LiTaO3 films, based on Curie temperature and dampings of Raman modes and taking into
account secondary effects, was developed.

348
349
350

A.M. Glazer, P.A. Thomas, N. Zhang, A. Bartasyte, D.S. Keeble, Patent WO/2011/158022, 2011.
A. Bartasyte and O. Elmazria, Patent F12 52410, 2012.

A. Bartasyte, V. Plausinaitiene, A. Abrutis, T. Murauskas, P. Boulet, S. Margueron, J. Gleize, S. Robert, V.
Kubilius, and Z. Saltyte, Appl. Phys. Lett., 101, 122902, 2012.

ISAF1-M1-4 _____________________________________________________________________________________________________________________

Study of LiNb1-xTaxO3 mixed crystals by Raman and IR
spectroscopy
A.Bartasyte1,2, S. Margueron3, A.M. Glazer2, E. Simon4, J. Hlinka4, I. Gregora4, P.A. Thomas5
1Institute Jean Lamour, (UMR 7198) CNRS – Lorraine University, Nancy, France
2
Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU, UK
3
Laboratoire Matériaux Optiques, Photonique et Systèmes, EA 4423, Lorraine University andSupelec, Metz, France
4
Institute of Physics AS CR, Prague 8, Czech Republic
5
Department of Physics, University of Warwick, Coventry, UK
Email: ausrine.bartasyte@univ-lorraine.fr
Lithium niobate (LN) and lithium tantalate (LT) have been subject of intense studies because of
their optical applications in industry. At room temperature LN and LT are isomorphous andferroelectric, crystallizing in the space group R3c. The ferroelectric LN and LT crystal structure canbe described in terms of polar displacements of the cations along the [0001] direction, with cornerlinked oxygen octahedra tilted according to the system a-a-a-. Despite LT and LN structuralsimilarity, these materials have different physical properties. Therefore, LiNb1-xTaxO3 (LNTx)
materials are of special interest because their properties can be tuned between those of LN and
LT351. However, the fundamental properties of LNTx solid solutions have not yet been investigatedsufficiently to date.
The dynamical properties of LN and LT have been intensively studied. The optical phonon
frequencies, damping parameters, and intensities are of special interest in studies of phasetransitions, symmetry, effect of pressure, stress, composition and heterogeneities in thin films,
integrated structures, nano and bulk materials. It is essential to know the frequencies in calculationsof dielectric constant , oblique modes , and electro-optic coefficients. There are numerous reports
concerning optical phonons in LT and LN, studied by Raman and infrared spectroscopies352,
neutron inelastic scattering and theoretically. Generaly speaking, dynamical properties of different
type of solid solutions have been extensively studied in literature. Nevertheless, there is only one
report on the study of LNT solid-solution zone-centre phonons.353 The authors studied only
LNT0.9, and claimed that the Raman mode assignment is similar to that of LT. LNTx with othercompositions of solid solutions and the change of zone-centre phonons with Ta/Nb ratio have neverbeen studied.
In this work, all 26 optical phonons at Γ point of LNTx single crystals were identified in polarized
spectra measured by IR and Raman spectroscopies. The effect of Nb replacement by Ta on the351

A. Bartasyte, A.M. Glazer, F. Wondre, D. Prabhakaran, P.A. Thomas, S. Huband, D.S. Keeble, and S. Margueron,
Mater. Chem. Phys. 134, 728-735, 2012.
352

S. Margueron, A. Bartasyte, A.M. Glazer, E. Simon, J. Hlinka, I. Gregora, and J. Gleize, J. Appl. Phys. 111, 104105,
2012.
353

Ge, Y.-C. and C.-Z. Zhao. J. Raman Spectroscopy, 26, 975-979, 1995.

wavenumbers, Raman efficiency coefficients, oblique mode dispersion and overlap matrix of zonecentre phonons over the whole composition range 0 ≤ x ≤ 1 was described.

ISAF1-M1-5 _____________________________________________________________________________________________________________________

Charged Domain Wall Conductivity in Lithium Niobateand Lithium Tantalate Single Crystals
Baturin Ivan1,2, Chezganov Dmitry1, Esin Alexander1, Shur Vladimir1,2,
Akhmatkhanov Andrey1,2, Ksenofontov Danila1
1

Ferroelectric Laboratory, Ural Federal University, Ekaterinburg, Russia
2
Labfer Ltd., Ekaterinburg, Russia
Email: ivan@labfer.usu.ru

Charged domain wall conductivity in lithium niobate (LN) and lithium tantalate (LT) single crystals
and its relaxation after polarization reversal have been studied. Strong increase of the conductivity
along the charged domain walls (CDW) was shown for the first time for head-to-head domain
structure in ferroelectric semiconductor SbSIxxxi. Recently conduction properties of domain walls
have attract a great attention with the progress in AFM characterization techniques. Electronic
conductivity along ferroelectric domain walls in multiferroic BiFeO3xxxii was observed using cAFM measurements. Moreover, the reversible resistance transition caused by the polarization
reversalxxxiii was found in ferroelectric MgO doped LN crystals, which is extensively used fordomain-engineered QPM nonlinear optical applications. Recently, the domain wall conductivity in
LN was studied by c-AFM in the presence of UV illuminationxxxiv. The observed resistive change
behavior is believed to be useful for memory applications2,3.
Z-cut LN and LT crystals with congruent and near stoichiometric composition as well as with MgO
doping have been used for the present study. CDW were fabricated by polarization reversal byapplication of the electric field at elevated temperature (100-250oC) using metal electrodes
deposited on both sides of z-cut samplesxxxv. Strong increase of the conductivity current wasobserved during polarization reversal in all studied LN and LT crystals due to CDW formation. Thisstrongly affects the domain patterning in MgO doped LN leading to decrease of applied field andsample fracture due to local heating. Absence of significant conductivity during polarization
reversal using liquid electrodes was attributed to formation of the neutral walls only.
Partial switching with different fraction of the switched area followed by immediate current
measurement was used to study the domain wall conductivity in details. It was shown that thedomain wall conductivity essentially relaxes after partial polarization reversal following exponential
decay behavior with the characteristics time of about tens of seconds. It was found that maximum
value of conductivity current is proportional to the switched area, which determines the total lengthof CDW. The maximum value of the effective conductivity was found to be several orders ofmagnitude higher than for single domain sample.
The equipment of the UCSU “Modern Nanotechnology”, Institute of Natural Sciences, UrFU has
been used. The research was made possible in part by RFBR (Grants 13-02-01391-а, 11-02-91066CNRS-а), by Ministry of Education and Science (Сontract 14.513.12.0006) and with the financial
support of young scientists in terms of Ural Federal University development program.

Piezoelectrics
CLUB B
Thursday, July 25 2013, 02:00 pm - 03:30 pm
Chair:To Be Aannounced

ISAF2-M2-1 _____________________________________________________________________________________________________________________

Dielectric & Piezoelectric Enhancement of Potassium
Niobate/Barium Titanate Nano-complex Ceramics with Parallel
Configuration of Structure-gradient Regions
Satoshi Wada1, Hideto Kawashima1, Shintarou Ueno1, Kouichi Nakashima1, andNobuhiro Kumada1
1

Material Science and Technology, Interdisciplinary Graduate School of Medical and Engineering,
University of Yamanashi, 4-4-37 takeda, Kofu, Yamanashi 400-8510, Japan
Email: swada@yamanashi.ac.jp

Barium titanate (BaTiO3, BT) and potassium niobate (KNbO3, KN) (BT-KN) nano-structured
ceramics with artificial morphotropic phase boundary (MPB) structure were successfully preparedby solvothermal method at temperatures below 230 ˚C. Especially, structure-gradient region (SGR)
can be expected to enhance piezoelectric and dielectric properties, and then, to induce parallel
configuration of SGR, new preparation method was proposed and developed in this study. As theresults, KN epitaxial layer was successfully deposited on BT nanoparticle accumulation withnecking structure between neighbored BT nanoparticles. Various characterizations confirmed thatthe BT-KN nano-structured ceramics exhibited BT/KN molar ratio of 1, a porosity of around 30 %and heteroepitaxial interface between BT and KN. Their apparent piezoelectric constant d33* wasestimated at 300 pC/N, and was eight times larger value than that of the 0.5BT-0.5KN dense
ceramics, while dielectric constant was estimated at 1600 at room temperature. The concept
proposed in this study can be a new way to create piezoelectric ceramics with artificial MPB region.
Moreover, this method is very universal and applied into various functional materials such as
magnetic, conductive, semi-conductive, and optical materials in addition to dielectric, piezoelectricand ferroelectric materials. In the future, we will develop various new materials withheteroepitaxial interfaces on the basis of the concept.

ISAF2-M2-2 _____________________________________________________________________________________________________________________

Chemically Modified Solution-Derived Na0.5K0.5NbO3 Thin
Films: From Macro- to Nanoscale Response
Sebastjan Glinšek1, Seung-Hyun Kim1, Lindsay Kuhn1, Alice Leung1 and Angus Kingon1
1School of Engineering, Brown University, Providence, USA
Email: sebastjan_glinsek@brown.edu

A great potential for applications in micro- and nanoscale devices is a driving force for the stillgrowing interest in thin-film piezoelectric materials. Among huge amount of applications, microelectro-mechanical system (MEMS) piezoelectric vibration energy harvesters could be used for
powering medical implants.354 For this purpose both thin-film and substrate materials have to be
non-toxic. For the substrates, stainless steel foils are good candidates since they are bio-compatible,
flexible and enable high-temperature processing, as well as ease of microfabrication.
The (Na,K)NbO3-based materials (NKN) are among the most promising lead-free piezoelectrics.355
However, in the thin-film form their properties are regularly deteriorated compared to the bulk
counterparts. It is believed that the problem arises mainly from high and differential volatility ofalkali compounds during heating. Therefore their functional properties are still not well understood,in particular, there is a strong need to link the measured macroscopic properties to the nanoscaledomain structure and local switching behavior.
With the aim of improving functional response NKN is often chemically modified. Our group
recently reported on strong enhancement of functional properties of the solution-derived NKNbased thin films by the addition of small amounts of BiFeO3 (BFO). The films with 5 % BFO haveroom-temperature value of the kHz-dielectric permittivity~600, leakage current density ~10-7
A/cm2 and piezoelectric coefficient d33 ~57 pm/V.356
In this paper our recent advances on NKN, NKN-LN (LiNbO3) and NKN-BFO solution-derived
films will be presented. The phase-pure perovskite films were prepared either on standard platinizedsilicon or flexible stainless steel substrates. In addition to the macroscale functional
characterization, piezoresponse force microscopy was employed to study domain structure and local
polarization switching behavior. Influence of different dopants, substrates and relationships between
the macroscopic performance and nanoscale properties will be addressed.

354

S.-G. Kim, S. Priya, I. Kanno, “Piezoelectric MEMS for Energy Harvesting”, MRS Bullettin, vol. 37, p. 1039 -50,
2012
355

J. Rodel, W. Jo, T. P. Seifert et al., “Perspective on the Development of Lead-Free Piezoceramics”, J. Am. Ceram.
Soc., vol. 92, p. 1153-77, 2009
356

S.-H. Kim, A. Leung, C. Y. Koo et al., “Lead-Free (Na0.5K0.5)(Nb0.95Ta0.05)O3-BiFeO3 Thin Films for MEMS
Piezoelectric Vibration Energy Harvesting Devices”, Mater. Lett., vol. 69, p. 24-26, 2012

ISAF2-M2-3 _____________________________________________________________________________________________________________________

CaBi4Ti4O15/PZT Sol-Gel Composite
for High Temperature Ultrasonic Transducers
Makiko Kobayashi1, Takuo Inoue2, Hajime Nagata3, Tadashi Takenaka3
1

Graduate School of Science and Technology/Kumamoto University, Kumamoto/Japan
2
Faculty of Engineering/Kumamoto University, Kumamoto/Japan
3
Faculty of Science and Technology/Tokyo University of Science, Chiba/Japan
Email: kobayashi@cs.kumamoto-u.ac.jp

In these days, high temperature ultrasonic transducers becomes in high demand. Especially in Japan,
old fuel plants are working in full load, and it is preferable to monitor minor problem points on-line which
are found during periodical off-line monitoring. However, the operation temperature of cooling pipes isabove 500C so that it is very severe conditions for ultrasonic transducers.
Sol-gel composite materials could be good candidates for those applications because of hightemperature durability and curved surface suitability. However, the composites with Bi 4Ti3O12 (BIT)
piezoelectric powder phase have difficulty for long term usage above 500C. The temperature stability of thecomposites with LiNbO3 is excellent, though the signal strength is not so high and its poling is relatively
difficult.
Therefore the sol-gel composite, between CaBi4Ti4O15 (CBT) piezoelectric powder and leadzirconate titanate (PZT) sol-gel was investigated for high temperature ultrasonic transducer applications.
CBT was chosen because of relatively high Curie temperature, ~800C. PZT sol-gel was chosen because ofhigh dielectric constant. CBT powder and PZT sol-gel was mixed together, then the mixture were sprayedonto a steel substrate with 4.2mm thick, ~50mm length, ~50mm width, respectively. Spray coating process
and thermal process was repeated several times. After poling, clear reflected echoes from the back surface ofthe substrate at room temperature.
In order to investigate high temperature performance of CBT/PZT, reflected echoes were monitoredfrom room temperature up to 550C. The signal strength was compared with BIT/PZT and PZT/PZT. As aresult, CBT/PZT showed the best temperature stability and it showed the almost same signal strength asthat of BIT/PZT. It is noted that no signal was obtained from PZT/PZT at 550C. Further research
will be presented regarding long-term high temperature durability test.

Fig. 111: Temperature dependence of used gain for 4Vp-p of 3rd reflected echoes.

ISAF2-M2-4 _____________________________________________________________________________________________________________________

Effect of the Powder Processing on Dielectric and Leakage Current
Properties of Flux Grown 94NBT-6BT Single Crystals
Mevlüt Gürbüz1,2 and Aydın Doğan1
1

Department of Materials Science and Engineering, Faculty of Engineering,
Anadolu University, 26555, Eskisehir, Turkey
2
Department of Mechanical Engineering, Faculty of Engineering,
Ondokuz Mayıs University, Samsun 55139, Turkey
mevlutg@anadolu.edu.tr
adogan@anadolu.edu.tr

Uncalcined 94NBT-6BT
Calcined 94NBT-6BT(a)2

Dielectric constant (r)

30000
25000
20000
15000
10000
5000

f=1kHz

0
0

100

200

300
o

Temperature ( C )

400

500

1000
Uncalcined 94NBT-6BT
Calcined 94NBT-6BT

(b)

-7

35000

Leakage current density [log ( A/cm ) ( x10 ) ]Abstract
Lead ziconate titanate based (PZT) ceramics have been used for years because of their excellent
electrical properties. However, the use of lead based piezoelectric materials cause to environmental
problems during processing due to toxic nature of lead. Therefore, use of lead based ceramics will be
prohibited by environmental regulations in near future1. In recently, the researchers have focused on toalternative lead free materials. 94Na0.5Bi0.5TiO3-6BaTiO3 (94NBT-6BT) based lead free ceramics arealternative materials instead of lead containing ceramics. NBT based materials and their variations areintensively investigated to enhance piezoelectric properties2. Recently, considerable research efforts
have been devoted to the growth of NBT based single crystals by various crystal growth methods, suchas flux growth, top seeded solution growth and solid state solution growth3. In this study, 94NBT-6BT
single crystals were grown by flux growth method using uncalcined and calcined 94NBT-6BT powder.
Influences of the powder processing type on dielectric and leakage current properties of the grown
94NBT-6BT crystals were analyzed by impedance/gain phase analyzer, LCR meter, AIXACT(aixPES/CMA) piezoelectric and ferroelectric analyzer. The results showed that, single crystals whichwere produced by heat-treated powders gave better dielectric and leakage current properties thanuncalcined single crystals (Figure 1).

100

10

1
o

T=90 C
0

5

10

15

20

25

30

35

40

Electric Field(kV/cm )Figure 1. Dielectric (a) and leakage current density (b) of the grown 94NBT-6BT crystals
Xu G., Duan Z., Wang X., Yang D. “Growth and some electrical properties of lead-free piezoelectric crystals (Na1/2Bi1/2)TiO3 and (Na1/2Bi1/2)TiO3–
BaTiO3prepared by a Bridgman method”, J.Cryst. Growth., 275, 113–119, 2005
2
Ge W., Liu H., Zhao X., Pan X., He T., Lin D., Xu H., Luo H., “Growth and characterization of Na0.5Bi0.5TiO3–BaTiO3 lead-free piezoelectric
crystal by the TSSG
1

method”, J. Alloy. Compd., 456, 503–507, 2008
Moon K.S., Rout D., Lee H.Yong., Kang S.J. L., “Solid state growth of Na1/2Bi1/2TiO3–BaTiO3 single crystals and their enhanced piezoelectric
properties”, J. Cryst.
Growth., 317, 28-31, 20113

ISAF2-M2-5 _____________________________________________________________________________________________________________________

Growth, Properties and Structure of High Performance PIN-PMN-PT Single Crystals
Zhuo Xu, Zhenrong Li, Fei Li, Shiji Fan and Xi Yao
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center
for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China

Ternary

Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3(PIN-PMN-PT)

crystalswithmorphotropic phase boundary (MPB) composition have attracted much interest due to the higher
ferroelectric-ferroelectric transition temperature TR-T (>120oC), improved EC (~5kV/cm), andsimilar piezoelectric properties (d33>1500 pC/N, k33>90%), when compared to binaryPb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) crystals. These properties make PIN-PMN-PT crystals goodcandidates for various transducer applications.
The paper reviews the recent progress of research on growth, piezoelectric/dielectric properties
and structure of PIN-PMN-PT single crystal in Xi’an Jiaotong University. (1) PIN-PMN-PT single
crystals of 2’ diameter and 3’ diameter were grown by the modified Bridgman technique. Variationsof composition of PIN-PMN-PT single crystal along growth direction were presented. The
homogeneity of PIN-PMN-PT single crystals is needed to be improved in the future. (2) Variationsof piezoelectric/dielectric properties of PIN-PMN-PT single crystal along growth direction were
measured in detailed. Phase transition characteristics of PIN-PMN-PT single crystals with different
composition were investigated. The phase diagram of PIN-PMN-PT was built. (3) The high shear
piezoelectric response with improved thermal stability (d24~2000 pC/N) was obtained inorthorhombic crystals. Meanwhile, the high electromechanical couplings k33 (>84%) andmechanical quality factors Q (>2000) were concurrently obtained in tetragonal crystals withbroadened temperature usage range. (4) Domain size effect in PIN-PMN-PT single crystal wasstudied. The piezoelectric constant d33 is improved with decreasing domain size. The fitting curveof the relationship between the domain size and d33 was obtained.

ISAF2-M2-6 _____________________________________________________________________________________________________________________

Dielectric Relaxation in Lead-Free (1-x)Bi0.5K0.5TiO3 – xBiFeO3
Ceramics with High Electromechanical Properties
Maxim Morozov, Mari-Ann Einarsrud, Tor Grande,
Department of Material Science and Engineering,
Norwegian University of Science and Technology, Trondheim, Norway
Email: maxim.morozov@ntnu.no

Perovskite ABO3 compounds with mixed bismuth and alkaline cations on the A-site are among theleading candidates for lead-free piezoelectric ceramics. In particular, the system of(1-x)Bi0.5K0.5TiO3 – xBiFeO3 (BKT-BFO) solid solutions includes the regions with appreciably
high and thermally stable electromechanical properties, in both sensor (at x ≈ 0.6)357 and actuator(at x ≈ 0.25)358 regimes. However, relatively highconductivity observed in the system, especially inthe region with high BFO content, is a challenge
for practical application.
In this contribution we investigate the dielectric
response of BKT-BFO ceramics in broadfrequency (1 mHz – 1 MHz) and temperature (25 –700 °C) ranges, as well as in various atmospheres(natural and synthetic air, N2, O2). The dielectricrelaxation in ceramics with high BFO content has
been analyzed in terms of a traditional model of
two parallel equivalent resistance-capacitancecircuits in series, which represents the “bulk” and“barrier” contributions by two semi-circles in thecomplex impedance plane. Our results demonstratethat the “barrier” contribution becomes moresignificant as the BFO content increases. The same Fig. 112: Complex impedivity plot for 30BKTtrend characterizes the conductivity of the “bulk” 70BFO ceramics after treatment in different
contribution. The “barrier” contribution can be atmospheres.
eliminated by heat treatment in dry synthetic air, while the resistivity of “bulk” contribution can beaffected by heat treatment in presence of an inert gas (Fig. 1). These results suggest that the“barrier”-type relaxation may originate from interaction with moisture, when ceramics is fabricated.
The “bulk” conductivity at ambient conditions is electronic in nature, and is likely associated withthe valence state of Fe, which is controlled by the oxygen partial pressure during thermal annealing.
357

H. Matsuo et al., “Structural and piezoelectric properties of high-density (Bi0.5K0.5)TiO3 – BiFeO3 ceramics”, J.
Appl. Phys., vol. 108, 104103, 2010.
358

M. I. Morozov et al., “Polarization and strain response in Bi0.5K0.5TiO3 – BiFeO3 ceramics”, Appl. Phys. Lett., vol.
101, 252904, 2012.

Thus, our study demonstrates the way to improve electric resistivity in BKT-BFO ceramics.

Smart Materials and Devices
CLUB C
Thursday, July 25 2013, 02:00 pm - 03:30 pm
Chair:To Be Announced

ISAF4-M3-1 _____________________________________________________________________________________________________________________

Ferroelectric Tunnel Junctions Based on Pseudotetragonal
BiFeO3
F.Y. Bruno1, V. Garcia1, S. Fusil1, C. Carretero1, C. Deranlot1, E. Jacquet1, K. Bouzehouane1, S.
Xavier1, M. Bibes1, and A. Barthélémy1.
1

Unité Mixte de Physique CNRS/Thales, Palaiseau, France and Université Paris-Sud, Orsay, France
Email: flavio.bruno@thalesgroup.com

The concept of a ferroelectric tunnel junction (FTJ) was formulated in the early 70s by Esaki et al.
It took more than 30 years to realize this idea experimentally in a reliable and reproducible manner1.
FTJs have shown to be versatile devices and the possibility to use them as memories2 andmemristors3 have been recently demonstrated on BaTiO3 based junctions. With the aim of
expanding its functionalities we have realized FTJ
with multiferroic pseudotetragonal BiFeO3 (TBFO) tunnel barriers. This polytype of BFO has alarge predicted polarization (>100 μC cm-2). We
will show by piezoresponce force microscopy(PFM) that thin films of BFO grown on and
LaAlO3 substrates are ferroelectric down to a 2.5
nm thickness. In order to fabricate junctions wedeposited fully epitaxial bilayers consisting of a
LaNiO3 bottom electrodes and the T-BFO tunnel
barrier. On top of this bilayers, Co/Au electrodes
as small as 200 nm in diameter were defined by ebeam lithography and lift-off. We have measured
ON/OFF ratios as large as 1000 on these Figure 1 Typical hysteresis of resistance withjunctions, much larger than that observed in FTJs write voltage pulses of a 300 nm widewith BaTiO3 tunnel barriers. In Figure 1 we show Pt/Co/BFO/LNO
capacitor
showing
typical hysteresis curve of resistance vs write reproducibility of the ON to OFF switching.
voltage pulses on a 300 nm capacitor. We willshow that the resistance of the FTJ in its high, low
and intermediate states is related with the polarization state of the barrier as observed by PFM. We
acknowledge financial support from the European Union Research Council (ERC Advanced Grant
Femmes, No. 267579).

ISAF4-M3-2 _____________________________________________________________________________________________________________________

Performance Investigation and Optimization of Si:HfO2-FeFETs
on a 28 nm Bulk Technology
Stefan Mueller1, Johannes Müller2, Alban Zaka3, Tom Herrmann3, Ekaterina Yurchuk1,
Uwe Schröder1, and Thomas Mikolajick1
1

NaMLab gGmbH / Dresden University of Technology, Dresden, Germany
Fraunhofer Center for Nanoelectronic Technologies, Dresden, Germany
3
GLOBALFOUNDRIES Dresden Module One LLC & Co. KG, Dresden, Germany
2

Email: Stefan.Mueller@namlab.com

In our present study we show that for different Si:HfO2
thicknesses, the experimentally observed ferroelectric
hysteresis can well be reproduced by a Preisach-based
TCAD modeling approach (Fig. 1)363. It was possible toverify that simulated sub-loop characteristics coincide withpolarization measurements and further support theassumption of true ferroelectricity in HfO2. The ferroelectricmodel was furthermore used for simulation of FeFETtransistors and their respective memory characteristics (Fig.
2). As shown by experiments, the ferroelectric properties
change depending on the thickness of the functional layer
and indicate that FeFET properties can be tailored byvarious parameters i.a. film thickness, dopant concentration
and annealing conditions. 30 nm layers possess an increased
Pr / Ps ratio, reduced permittivity and smaller remanentpolarization in general. It is shown by simulation that the359

J. L. Moll, IEEE Trans. Electron Dev., vol. ED-10, p. 338, 1963.

360

T. P. Ma, IEEE Electron. Dev. Lett.,, vol. 23, pp. 386-388, 2002.

361

T. S. Böscke, Appl. Phys. Lett., vol. 99, p. 102903, 2011.

362

J. Müller, IEEE Symp. on VLSI Tech., pp. 25-26, 2012.

363

B. Jiang, IEEE Symp. on VLSI Tech., pp. 141-142, 1997.

2] [µC/cm2] [µC/cm2]
Polarization[µC/cmPolarization
Polarization

Ferroelectric field effect transistors (FeFET) have long been envisioned as low-power, non-volatilememory solution359. However, mass storage based on these30
devices has never reached maturity due to limited
Pr = 9 µC/cm2
Ps = 9.5 µC/cm2
scalability, low retention and CMOS incompatibility360.
15
Ec = 1.1 MV/cm
Only recently, these obstacles seem to have been resolved
 = 3230
0by the discovery of ferroelectric properties in silicon doped
Pr = 2 µC/cm2
10 nm
Ps = 2.005 µC/cm2
hafnium dioxide (Si:HfO2)361. 28 nm FeFET devices making
15-15
Ec = 0.9 MV/cm
Experimentuse of this novel ferroelectric material could finally close the = 2530
0-30Simulation
gap to the logic technology roadmap and possess thePr = 2 µC/cm2
15-15
potential of realizing highly-scaled ultra low-power memory2
Ps = 2.005 µC/cm
Ec = 0.9 MV/cm
cells362.
0-30
 = 25-15-4 -3 -2 -1 0 1 2 3 4
30 nm
Electric Field [MV/cm]-30-4 -3 -2 -1 0 1 2 3 4Electric Field [MV/cm]

Fig. 1. Measured and simulated
polarization hysteresis for 10 nm
and 30 nm Si:HfO2 MFM
capacitors.

tHK =10nm

tHK =30
nm

Fig. 2. Simulated electron density
at VG = 0V after EHK  2.5
MV/cm program operation.

interfacial field stress can be reduced using thicker Si:HfO2 layers which might contribute to FeFET
endurance optimization in the future.

ISAF4-M3-3 _____________________________________________________________________________________________________________________

A 3.8 GHz tunable filter based on Ferroelectric InterdigitatedCapacitors
Areski GHALEM, Freddy Ponchel, Denis Remiens, Tuami Lasri
Email: Denis.Remiens@univ-valenciennes.fr
In recent years, ferroelectric materials especially BaxSr(1-x)TiOx have shown interesting properties
for telecommunication applications. Actually, the combination of the good tunability and therelatively low losses [1] offered by this kind of material makes it a very interesting candidate for thedevelopment of reconfigurable devices. Another advantage brought by the ferroelectric based thinfilm technology is the suitability for highly integrated microwave devices compatible with planar
circuits. The dielectric characterization at 3.8 GHz using a specific coplanar waveguides has showna tunability of 44% (applied electric field Emax = 300 kV/cm) and a loss factor (tan δ) of 2%. The
measurement of the ferroelectric interdigitated capacitors (IDC), conceived and realized, has showna tunablity of 35% under a low electric field (150 kV /cm) .Finally, the realization of a tunable
hairpin filter using these IDCs (figure 1) has been achieved. The results of the microwave
characterization of this device are given in figure 2.

Fig. 1: Photograph of tunable hairpin filter.

Fig. 2: Frequency evolution of S11 and S21 parameterfor different polarization conditions

The measurement of S11 and S21 parameters has been done for different bias voltage ([0; 30 V]
range by 2V step). The experimental results clearly show that the variation of permittivity of BST
film through the bias voltage modification gives rise to a frequency shift of reflection andtransmission parameters. The effect of polarization is translated by a modification of the material
permittivity. The measurement exhibits a frequency shift from 3.5 GHz at 0V to 3.9 GHz at 30V.
The filter has a tuning frequency of 11.4 % (under 300 kV/cm).

1

F. Ponchel, J. Midy, J. F. Legier, C. Soyer, D. Rèmiens, T. Lasri, and G. Guéguan. “Dielectric microwave
characterizations of (Ba,Sr)TiO3 film deposited on high resistivity silicon substrate: Analysis by two-dimensionaltangential finite element method”. Journal of Applied Physics, [107], 054112, 2010.

ISAF4-M3-4 _____________________________________________________________________________________________________________________

Fabrication of Bimorph with Double Pb[Zr,Ti]O3 Thick Films
Jun-ichi Inoue1, Kensuke Kanda1, Takayuki Fujita1, Kazusuke Maenaka1
1

Graduate School of Engineering, University of Hyogo, Himeji, Hyogo/ Japan
Email: kanda@eng.u-hyogo.ac.jp

Top electrode

Piezoelectric Pb[Zr,Ti]O3 (PZT) bimorph structures with the total
thickness of 5.4 μm are fabricated and characterized. Optimizationsof the sputtering conditions for PZT and metals result in goodpiezoelectric characteristics of the PZT/PZT thick films.

Middle electrode

Bottom electrodeSiO2
Si substrate

Top PZT

Bottom PZT

3 mBimorph structures are useful for enlarging actuation displacement
and generative force. Challenges to fabricate thin-film PZT/PZT Fig. 113: Cross-sectional SEM image
bimorphs have been reported for the device application and of PZT/PZT layers.
miniaturization. Since conventional PZT/PZT bimorphs have beenquite thin (typically less than 1 μm) 364365366, it has been difficult toapply to specific devices, e.g. bimorph beam vibrating and supporting
proof mass in MEMS gyroscopes. The thickness of the fabricated
PZT/PZT bimorph is enough thick to adapt the bimorph to MEMS
structures. The performed bimorph is made by complete batchprocess without troublesome bonding between bulk PZT material andSi wafer.
Fig. 1 shows the cross sectional SEM (scanning electron microscopy)
image of the sputtered PZT/PZT layers. Both PZT layers are dense Fig. 2: P-E hysteresis loop for top andand columnar crystalline structures without cracks and pores. The P- bottom PZT layers.
E (polarization and electric field) curves demonstrate that the PZTlayers have preferable ferroelectric characteristics (Fig. 2). In
addition, other electrical properties of the two PZT layers are wellmatched with each other. Test cantilevers are fabricated by using dry
etching processes to evaluate the characteristics. The relationshipbetween the applied voltage and tip displacement of a 1-mm-longcantilever for unimorph and bimorph actuation (parallel drive) isshown in Fig. 3. The bimorph actuation doubled in the tip
displacement compared to the unimorph actuations. The estimatedpiezoelectric d31 value about -40 pm/V is larger than our previous
Fig. 3: Applied voltage vs. tip
work for thin PZT/PZT bimorph3.
displacement of the cantilever.
(@500Hz, resonant frequency: 2.86
kHz)
364

J. Tsaur et al., “Design and Fabrication of 1D and 2D Micro Scanners Actuated by Double Layered Lead Zirconate
Titanate (PZT) Bimorph Beams”, Jpn. J. Appl. Phys., vol. 41, p. 4321-4326, 2002.
365

D. F. L. Jenkins, et al., “PZT Thin Film Bilayer Devices for Phase Controlled Actuation in MEMS”, J.
Electroceram., vol. 7, p. 5-11, 2001.
366

K. Kanda, et al., “Fabrication and Characterization of Double-Layer Pb(Zr,Ti)O3 Thin Films for MicroElectromechanical Systems”, Jpn. J. Appl. Phys., vol. 51, 09LD12, 2012

ISAF4-M3-5 _____________________________________________________________________________________________________________________PZT PIEZOELECTRIC FILMS ON GLASS FOR ADJUSTABLE XRAY OPTICS
Rudeger H.T. Wilke1, Raegan L. Johnson-Wilke1, Susan Trolier-McKinstry1, Vincenzo Cotroneo2,
Stuart McMuldroch2, Paul B. Reid2 and Daniel A. Schwartz2
1

Materials Research Institute, The Pennsylvania State University, University Park, USA
2
Harvard-Smithsonian Center for Astrophysics, Cambridge, USA
Email: rhw11@psu.edu

Adjustble X-ray optics, using piezoelectric lead zirconate titanate (PZT) films deposited on
slumped, thin glass substrates, are a candidate for the Square Meter Arc Second X-ray Telescope(SMART-X) mission concept. The mirror pieces are shaped in the form of paraboloids andhyperboloids with an iridium mirror deposited on the concave surface of the glass and a PZT film
deposited on the convex surface. The geometrical constraints make processing of the PZT films bychemical solution deposition quite complex. As a result, an RF magnetron sputtering approach has
been adopted. PZT films were deposited on Corning Eagle glass substrates. Two different shaped
substrates were used; one in the form of flat 100 mm rounds and the second in cylinders slumped
along an axial direction with a radius of curvature of 220 mm. Crystallization into the perovskite
phase was performed at 550 oC, approximately 100 oC below the strain point of the glass substrates.
Films deposited on flat round substrates demonstrate the feasibility of using PZT thin films toprovide high precision control of the surface figure of the mirror. Influence function measurementsof the 1.5 μm thick films indicate 2.5 μm out of plane deflection for 1 cm2 actuators at a drive levelof +10 V, in good agreement with finite element analysis models. Depositions onto curved
substrates were carried out using multiple sputter guns to ensure optimal film thickness uniformity
across the two axes of the cylinder. The electrical and eletromechanical properties of the PZT films
on curved glass were comparable to those of films deposited on flat pieces. The permittivity of thefilms was 1500 at 100 Hz, with a loss tangent of 0.04. The hysteresis loops were square withremanent hysteresis values approximately 21 C/cm2 and coercive field values near 30 kV/cm.
Initial results for influence functions on the curved substrates (measured along the axial direction)
show a 0.4 m deflection for an actuator driven at 4 V (40 kV/cm). The deflection profile about theactuator matches finite element model predictions.

ISAF4-M3-6 _____________________________________________________________________________________________________________________

Giant Piezoelectric Response in Nanostructured FerroelectricThin Film Membranes
Nazanin Bassiri-Gharb1, 2, Yaser Bastani1, Amit Kumar3, Sergei Kalinin3
1G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA,
USA
2School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA
3
Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN, USA
Email: nazanin.bassirigharb@me.gatech.edu

PZT and relaxor-ferroelectric solid solutions with polymorphic phase boundaries have been to thedate the industry standard for many piezoelectric applications (such as underwater sonars, medical
ultrasounds, acoustic transducers, as well as MEMS sensors and actuators, environmental energy
harvesters, microfluidic and inkjet printer pumps, …), owing to their very large piezoelectric
response, with respect to the non-ferroelectric compositions, such as ZnO and AlN. However, while
the presence of phase boundaries usually corresponds to an enhancement of the electromechanicalresponse by factors of 4x to 10x, the piezoelectric responses of PZT and other ferroelectric solid
solution ceramics at the MPB are still relatively small with respect to the intrinsic lattice strains. In
fact, in comparison, many other phase-separated systems (such as giant magnetoresistive
manganites) demonstrate enhancement of response by many orders of magnitude. Here, we argue
that the long-range elastic interactions that give rise to the mesoscopic clustering in disorderedferroelectrics are the predominant reason for suppressed enhancement factors in these systems.
(100)-textured PZT thin films were processed on platinized Si substrates, and their dielectric andpiezoelectric response was monitored at reduction of the Si thickness over a large area (~ 1 cm2).
The reduction of the Si thicknesses below ~ 200 m is accompanied with a continuous and large
enhancement of the effective piezoelectric response, d33,f, as measured by a double beam laserinterferometer. At a residual Si thickness of ~10-20 m, d33,f values up to 10 nm/V are observed in
the membrane-like PZT films. Band-excitation piezoresponse force microscopy (BE-PFM) wasused to characterize the local response of the samples. Virgin PZT capacitors showed a typicalcluster-like response previously observed in many ferroelectric ceramics and thin films. Conversely,
the piezoresponse amplitude of the membrane capacitors showed huge enhancement, more than anorder of magnitude with respect to the clamped sample, no long-range interactions were present,
and switching happened in a one by one paradigm of grains. A combination of the dielectric andpiezoelectric macroscopic measurements, X-ray maps, and PFM data are presented to illustrate that
long-range elastic interactions in the clamped ferroelectric films are the primary factor that limits
the giant electromechanical responses, even at the MPB compositions, in such systems.

ISAF Group 4 Posters
Forum Hall
Thursday, July 25 2013, 01:00 pm - 04:30 pm

ISAF-P4D-1 _____________________________________________________________________________________________________________________

Jonathan Bock1, Soonil Lee2, Susan Trolier-McKinstry3, Clive Randall3
1
Materials Science and Engineering, The Pennsylvania State Univerity, University Park, PA, USA, 2Materials ResearchInstitute, The Pennsylvania State University, University Park, PA, USA, 3Materials Science and Engineering, The
Pennsylvania State University, University Park, PA, USA

Electrical Conductivity in Heavily Reduced Ferroelectrics near the Mott Metal-Insulator Transition
Heavy reduction of ferroelectrics can lead to carrier concentrations above the Mott metal-insulatortransition and, therefore, metallic conductivity. Some of these materials show promising properties
for their use in thermoelectric applications due to their low thermal conductivities (Figure of Merits>1). Recent data shows that the paraelectric-ferroelectric transition in materials such as(Ba,Sr)TiO3-δ and (Sr,Ba)Nb2O6-δ show a transition from metallic conduction in their paraelectricstates to semiconducting behavior in their ferroelectric states. The nature of this metal-insulatortransition is currently unknown but is suspected to be caused by shifts in carrier concentrations dueto the need for screening of the polarization within the domains that form during the paraelectricferroelectric transition. Electrical conduction mechanisms within different temperature regimes aswell as evidence for a polarization induced metal-insulator transition will be discussed.

ISAF-P4D-2 _____________________________________________________________________________________________________________________

Photochemical Deposited Metal Nanoparticles on
Polarized LiNbO3 Surface for SERS Applications
1

Xiaoyan Liu1, Kenji Kitamura2, Minoru Osada2, and Guozhong Cao1
Dept. of Materials Sci. & Eng., University of Washington, Seattle, USA,
2
National Institute for Materials Science, Tsukuba, Japan
Email:xyliu@uw.edu

By applying an alternating external electric field, ferroelectric domains with patterned-polar
surfaces ranging from micro- to nano-meters under precise control and rational design can be
fabricated in LiNbO3 single crystal.1 Domains with different polarization present surfaces withdifferent properties including surface charges and surface potential. The use of ferroelectric LiNbO3
as templates for growth of patterns of metal
nanoparticles via photochemical reaction
related to surface charge properties has foundpotential applications in surface enhanced
Raman scattering (SERS) sensors.
As an example, when polarized surface of
LiNbO3 contacts to a metal ion solution andexposes to an above-band-gap irradiation, metal
nanoparticle
patterns
associatewith
Fig.1: Ag nanoparticles deposited selectively
ferroelectric domains can be formed due to aon positively-poled domain surfaces of2large photogalvanic effect of LiNbO3.
LiNbO .
Fig.1 is an AFM topographic image showing the 3 high contrast Ag nanoparticle pattern
fabricated on the positively-poled domain surfaces of LiNbO3. Zoom-in image (right) shows theuniformity of Ag nanoparticles at an average diameter of 30 nm. A variety of metal nanoparticles
including Au, Ni and Co can be fabricated using the same method.
The success of SERS is highly dependent on the interaction between adsorbed molecules and thesurface of plasmonic nanostructures, often the classic SERS substrates of Au and Ag. Although,
SERS effect is known for nearly four decades, search
for the suitable substrate is still under active area of
research. An ideal SERS substrate should be uniform,
EF > 10^8reproducible, and robust while exhibit high SERS
enhancement over large active area. Fig.2 shows the
SERS spectra of porphyrin molecules adsorbed on Au
nanoparticles photochemical deposited on LiNbO3 that
Conventionalpresent a large enhancement factor more than 108 (redline). The SERS signals also show a highreproducibility cross the Au nanoparticle regions. The
results demonstrate the photochemical deposited Ag
and Au nanoparticles on LiNbO3 can be used for an
improved SERS substrate. Besides the application to Fig.2: Raman enhancement from our
SERS substrate, we report here new applications of substrate and a conventional SERS
LiNbO3 templates for molecular manipulations.
substrate with Au nanoparticles.
1. X. Liu et al. Appl. Phys. Lett. 2006, 89, 142906.

2. X. Liu et al. Appl. Phys. Lett. 2007, 91, 044101.

ISAF-P4D-3 _____________________________________________________________________________________________________________________

Microwave Dielectric Constant Measurements of Strontium
Titanate Using Five Mixture Equations
Jyh Sheen* and Yong-Lin Wang
Department of Electronic Engineering, National Formosa University,
Hu-Wei, Yun-Lin 632, Taiwan.
*E-mail: jsheen@nfu.edu.tw
This research dedicates to find a different measurement
procedure of microwave dielectric properties for ceramicmaterials with high dielectric constants.

300

d=300Measurements
For the composite of ceramic dispersed in the polymer matrix,
200
one major development is to calculate the permittivity ofceramic from measurements on composite based on the mix
Bruggeman I
Bruggeman II
mixture rules 367-2. It has shown that both the physical curve
100
matching with experimental results and low potential theory
Aspneserror are important to promote the calculation accuracy 3. The
Rayleigh
Modifiedstudy of mixture equation with high dielectric constantWagnerceramics at microwave frequency has also been presented for
0
4
0
0.2
0.4
0.6
0.8
1
strontium titanate (SrTiO3) , which has a dielectric constantVd
300. The accuracy on the report of high dielectric constantFigure 1 Comparisons of experimental datameasurements is can still be improved. There are still some and mixture rules.
important and well known mixture rules require adequate
investigation to the application for measurements of high dielectric constant ceramics. Therefore,
five more well known mixing rules are selected to understand their application to high dielectric
constant ceramic. Their theoretical error equations are derived and investigated.

Strontium titanate is an interesting ceramic for microwave applications. In this research, its powder
is adopted as the filler material and polyethylene powder is as the matrix material. The dielectric
constants of those ceramic-polyethylene composites with various compositions were measured at 10
GHz. The theoretical curves of the five published mixture equations are shown together with themeasured results in Fig. 1 to understand the curve matching condition of each rule. Finally, basedon the experimental observation and theoretical analysis, one of the five rules was selected andmodified to a new powder mixture equation (Fig. 1). This modified rule has shown very good curve
matching with the measurement data and low theoretical error. We can then calculate the dielectric
constant of pure filler medium (strontium titanate) by those mixing equations from the measured
dielectric constants of composites. The accuracy for estimating dielectric constant of pure ceramic
by various mixture rules was compared. The modified mixture rule has also shown goodmeasurement accuracy on the dielectric constant of strontium titanate ceramic. This studied can beapplied to the microwave dielectric properties measurement of other high dielectric constantceramic materials in the future.
367

F. Xiang, H. Wang, and X. Yao, J. Eur. Ceram. Soc., vol. 26, pp. 1999-2002, 2006.
W. Z. Yang and J. P. Huang, J. Appl. Phys., vol. 101, p. 064903, 2007.
3
J. Sheen and Z. W. Hong, European Polymer Journal, vol. 45, pp. 1316-1321, 2009.
4
J. Sheen and Y. L. Wang, To be published.
2

ISAF-P4D-4 _____________________________________________________________________________________________________________________

UV direct-write domain inversion on 128˚ YX-cut LiNbO3:
towards novel SAW applications
Andreas Boes1,2, Didit Yudistira1, Amgad Rezk1, Tristan Crasto1,2, Hendrik Steigerwald1,2,
Elisabeth Soergel3, Scott Wade4, James Friend1, Arnan Mitchell1,21Electrical and Computer Engineering, RMIT University, VIC 3001, Melbourne, Australia
2
Center for Ultra-high Bandwidth Devices for Optical Systems (CUDOS)
3
Institute of Physics, University of Bonn, Wegelerstr. 8, 53115 Bonn, Germany
4
Engineering and Industrial Science, Swinburne University of Technology, VIC 3122, Australia
Email: andreas.boes@rmit.edu.au
Applications of domain engineered lithium niobate crystals (LiNbO3), in particular the periodic
domain inversion for surface acoustic wave (SAW) generation, has been reported recently368.
Domain inversion was achieved by means of electric field poling on Z-cut LiNbO3 crystals.
However, utilizing a 128˚ YX-cut LiNbO3 for SAW is preferable because of its higher
electromechanical coupling constant (5.3%) as compared to Z-cut crystals (0.53%)1. Domain
engineering has so far not been reported for 128˚ YX-cut LiNbO3 crystals because of its inclined
polarization axis, which makes it difficult to use standard electric field poling369. In this contribution
we report for the first time to our knowledge of periodic domain inversion on 128˚ YX-cut LiNbO3
whereby domain inversion is achieved using UV direct domain writing370.
For domain formation, tightly focused, continuous wave UV
laser light (l = 244 nm, I = 3.2 x 105 W/cm2, d = 6 µm) was
scanned across the crystal's surface. Laser tracks were
written perpendicular to the crystallographic x-axis with avelocity of 0.1 mm/s by the use of a computer-controlled
translation stage. The written domain pattern wasinvestigated using piezoresponse force microscopy (PFM).

x

10µm

The four bright stripes in the PFM picture (Fig. 1) show UVwritten domains on a 128˚ YX-cut LiNbO3 crystal. In the Fig. 114: PFM picture of the UVpicture is also evidence of surface damage and cracks, which written domains on a 128˚ YX-cut
LiNbO3 crystal. Small cracks andare a common feature of UV written domains.
surface damage are visible.

We have successfully demonstrated that the UV domain
writing technique is capable of achieving periodic domain inversion on 128˚ YX-cut LiNbO3 in the
micrometer regime. Promising methods for the suppression of the observed surface damage are also
under investigation. The suitability of these structures for the generation of SAW has been analyzed
theoretically and is the topic of a distinct submission to this conference. We hope to experimentallyobserve the use of these structures for SAW transduction shortly and will report our progress
towards this goal at the conference.
368

D. Yudistira, S. Benchabane, D. Janner, and V. Pruneri, “Surface acoustic wave generation in ZX-cut LiNbO3 superlattices using
coplanar electrodes,” Applied Physics Letters, 95, 052901 (2009).
369
S. Sonoda, I. Tsuruma, and M. Hatori, “Second harmonic generation in a domain-inverted MgO-doped LiNbO3 waveguide byusing a polarization axis inclined substrate,” Applied Physics Letters, 71, 3048 (1997).
370
H. Steigerwald, Y. J. Ying, R. W. Eason, K. Buse, S. Mailis, and E. Soergel, “Direct writing of ferroelectric domains on the x- andy-faces of lithium niobate using a continuous wave ultraviolet laser,” Applied Physics Letters, 98, 062902 (2011).

ISAF-P4D-5 _____________________________________________________________________________________________________________________PLD Elaboration of Piezoelectric ZnO Thin Film for 540 MHz
Al/ZnO/Pt Bulk Acoustic Wave Resonator
Serhane Rafik1, Abdelli-Messaci Samira1, Lafane Slimane1, Khales Hammouche1, Aouimeur
Walid1, Hassein-Bey Abdelkadder1,2, Boutkedjirt Tarek3
1

Centre for Development of Advanced Technologies (CDTA). Cité 20 Août 1956, Baba Hassen,
BP: 17, DZ-16303, Algiers, Algeria.
2
Micro & Nano Physics Group, Faculty of Sciences, University Saad Dahlab of Blida (USDB), BP.
270, DZ-09000 Blida. Algeria
3
Equipe de Recherche Physique des Ultrasons, Faculté de physique, Université des Sciences et dela Technologie Houari Boumediene (USTHB), BP 32, DZ-16111, El-Alia, Bab-Ezzouar,
Algiers. Algeria.
Email: rafik_serhane@hotmail.com, rserhane@cdta.dz
ZnO thin films in Al/ZnO/Pt/Ti/SiO2/Si Bulk Acoustic Wave (BAW) resonators are realized byreactive Pulsed Laser Deposition (PLD) technique. It is of most interest to improve theirpiezoelectric characteristics. These later are intimately linked to the texture, the microstructure andgrowth conditions. In this work, piezoelectric characteristics of ZnO thin films have been
investigated. The Wurtzite ZnO thin films were prepared on Pt(111) at different substratetemperatures (100-500 °C) by a reactive PLD technique. The 200 nm of Pt on 20 nm Ti wereprepared by Electron Beam Deposition (EBD) technique at room temperature on 2 µm SiO2
substrate. This SiO2 film has been realized by Silicon wet thermal oxidation step, under (H2+O2)(5slm+3.5 slm) gas flows at 1100 °C for 9h 10min. The top electrode of the BAW was made bythermal evaporation of Aluminum; the piezoelectric film was confined in a circle of 1.8 mm radius.
The X-Ray diffraction (XRD) characterization showed that the deposited Pt (bottom electrode) has(111) preferential orientation. It also showed that the ZnO films were c-axis (002) oriented. The
Scanning Electron Microscopy (SEM) of the realized ZnO thin film showed evidence of compact
grains with honeycomb-like structure on surface and evidence of columnar structure on crosssection. The measurements indicate that all substrate temperatures are suitable to obtain a goodquality of ZnO, but Ts=300 °C is the optimized one. In order to evaluate the piezoelectric propertiesof the BAW, measurements of the electrical input impedance and admittance have been performed.
They showed evidence of piezoelectric response. The resonance frequency was obtained at 524.5
MHz and the anti-resonance frequency at 540.9 MHz. The values of quality factors wererespectively; Qr=1125.6 and Qa=856.51. The electromechanical coupling coefficient was evaluatedat Keff2=7.26 %, which is an indicator of a good piezoelectric response. From this measured values,
the thickness and wave velocity in the ZnO slab were deduced to be (d = 6.15 µm and Vp = 6451.35m/s) and the piezoelectric constant e33 was found to be equal to 1.21 C/m2.

ISAF-P4D-6 _____________________________________________________________________________________________________________________

Ferroelectric Liquid Crystals for Display and Photonics
Applications
Vladimir Chigrinov
Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong
Email: eechigr@ust.hk
Ferroelectric liquid crystals (FLC) is a good candidate for the new generation display andphotonics devices with advanced performance in comparison with usually used nematic LC. Several
electrooptical modes can be used for for the new generation of FLC devices for displays andphotonics [1]: (i) deformed helix ferroelectric (DHF) effect; (ii) electrically suppressed helix
ferroelectric liquid crystals (ESHFLC); (iii) modulation of light in diffraction FLC grating; and (iv)orientational electro-optic Kerr effect.
The novel FLC devices may include field sequential color (FSC) FLC with a high resolution, lowpower consumption and extended color gamut, which can be used in the screens of portable PCs,
mobile phones, PDAs and micro and pico-projectors.
FLC photonics devices have found applications for the generation of digital holograms, adaptive
beam steering systems, sensors and polarization gratings. Additionally, high-speed communication
systems, producing elements (such as switches, attenuators, polarization rotators) demand FLC
devices with extremely fast response, stable, low loss, operable over a wide temperature range, andthat require small operating voltages and extremely low power consumption.
[1] Vladimir Chigrinov, Eugene Pozhidaev, Abhishek Srivastava, Guo Qi, Ma Ying, Hoi Sing
Kwok, Fast Ferroelectric Liquid Crystal Modes Based on Photoaligning Technology, SID 2013,
Vancouver, Canada, May 2013.

ISAF-P4D-8 _____________________________________________________________________________________________________________________

Piezoelectric Transducer Applications on Basis of Free-formed
PZT Components
Kai Hohlfeld 1, Sylvia Gebhardt 2, Alexander Michaelis 1,2
1

Chair of Inorganic Non-Metallic Materials, Institute of Materials Science / TU Dresden,
Dresden, Germany
2
Fraunhofer Institute for Ceramic Technologies and Systems (IKTS), Dresden, Germany
Email: kai.hohlfeld@ikts.fraunhofer.de

Adaptive structures are the future trend in several fields of mechanical engineering, automotive andaerospace industries. Since lightweight materials and composite structures are used more
extensively in these fields there is an increasing demand of systems for vibration/noise damping,shape control and structural health monitoring. Usually adaptive structures are created from passive
structural parts with subsequent application/integration of sensor/actuator modules and electronics.
We investigate volume fabrication of piezoceramic components with regard to cost-effectivenessand direct integration into lightweight materials within Collaborative Research Centre/Transregio
39 PT-PIESA supported by the Deutsche Forschungsgemeinschaft (DFG)1. Our focus is on thedevelopment of free-formed lead zirconate titanate (PZT) components and resulting PZT/polymer
composites as basis for sensor, actuator and ultrasonic transducer applications.
So far sintered PZT fibers (SP505, CeramTec, Germany) of 100-800 µm in diameter and up to
150 mm length were generated by a quasi-continuous spinning process and a modified phase
inversion technique. Furthermore nearly spherical PZT elements – so called pearls – in a diameter
range of 0.8-1.6 mm were manufactured. The paper reports on low and high signal properties of
piezocomposites made of free-formed PZT elements. 1-3 fiber composites fabricated from
PZT/polymer blocks with dense fiber packing (approx. 75 vol% PZT fibers) reached values ofdielectric constant εT33/ε0 = 800-1000 and electromechanical coupling kt = 0.56-0.63. Remnant
polarization Prem = 20-28 µC/cm2 and relative strain response Srel = 1-1.2×10-3 were measured at
E = 2 kV/mm. Composites based on PZT pearls showed εT33/ε0 = 200-600, Prem = 6 µC/cm2 andSrel = 0.6-0.9×10-3. Coercive field strength Ec = 1.3 kV/mm and dielectric loss factor tan δ = 0.2
were determined for both composite types.
Due to high values in ferroelectric coupling and strain
response fibers or fiber composites respectively are seen as
suitable for a variety of actuator and ultrasonic transducer
applications. Composites based on spherical PZT elements
offer advantages in manufacturing and handling. According
to their properties they could be introduced as basis material
for cost-effective sensors. Applications of integrated freeformed PZT components and composites in glass fiber
reinforced polyurethane-, thermoplastic polymer- (e.g.
polyamide) as well as aluminum sheet-structures to develop
adaptive structures compatible for high volume production Fig. 115: Novel PZT elements: pearls,
with approx. diameter of 1.2 mm.
will be shown.
1

www.pt-piesa.tu-chemnitz.de

ISAF-P4D-9 _____________________________________________________________________________________________________________________

Enhanced Electrocaloric Effect in Novel Lead-Free Relaxor
Ferroelectrics.
Florian Le Goupil1, Andrey Berenov1, Anna-Karin Axelsson1, Matjaz Valant2 and Neil McN.
Alford1
1
Department of Materials, Imperial College London, London, United Kingdom
2
Materials Research Laboratory, University of Nova Gorica, Nova Gorica, Slovenia
Email: f.le-goupil09@imperial.ac.uk
In polar crystals the spontaneous polarization increases with application of an external electric field.
Under adiabatic conditions, the system compensates this alignment of dipoles with an increase intemperature, in order to keep the overall entropy of the system constant. This phenomenon is called
the electrocaloric effect (ECE). The need for more efficient and environmentally-friendly materials
in the refrigeration industry has lead to a significant effort towards the discovery of materials thatexhibit a pronounced EC effect.
We have constructed a direct ECE measurement system, based on a modified-Differential Scanning
Calorimeter (DSC), allowing the acquisition of both thermal (ECE, heat capacity) and electrical (PE loops, leakage current) information simultaneously. The ECE of several novel lead-free relaxor
ferroelectric have been measured, including perovskites (substituted BaTiO3), Aurivillius phases(substituted SrBi2Ta2O9) and tungsten bronzes (SrxBa(1-x)Nb2O6). For most of these systems, thedirect ECE measurements presented here are the first ever reported. It is shown that, most definitely
due to their polar nano-regions, relaxor ferroelectrics experience a second ECE peak, sometimes far
above the temperature of the ferroelectric phase transition, which could provide the wide
temperature range that is required to establish a solid-state electrocaloric cooling cycle.
Comparisons between direct and indirect measurements, obtained from dielectric polarization
measurements versus electric field and temperature, have also been performed on these systems.
Contrary to what we reported for normal ferroelectrics371, we found large discrepancies between
both methods above the ferroelectric phase transition, in both trend and absolute values. This result
highlights the significant limitations of the indirect ECE method, especially in the case of relaxor
ferroelectrics.

371

F. Le Goupil, A. Berenov, A. Axelsson, M. Valant, and N. M. Alford “Direct and indirect electrocaloric
measurements on <001>-PbMg1/3Nb2/3O3-30PbTiO3 single crystals”, J. Appl. Phys., vol. 111, p. 124109, 2012.

ISAF-P4D-10 ____________________________________________________________________________________________________________________

Enhanced dielectric properties of BaTiO3/poly(vinylidene
fluoride) nanocomposites for energy storage applications
Ke Yu1, Hong Wang1, Yongcun Zhou1, Yuanyuan Bai1, Yujuan Niu1
1

Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education,
Xi’an Jiaotong University, Xi’an 710049, China
Email: ke.yu.ke@stu.xjtu.edu.cn

In our present work372, homogeneous ceramicspolymer nanocomposites consisting of surface
treated BaTiO3 (BT) particles as fillers andpoly(vinylidene fluoride) (PVDF) polymer as
matrix have been prepared using a solution
casting process.
The nanocomposites exhibit enhanced dielectric
permittivity and reduced loss tangent. The
frequency and temperature dependencies of thedielectric permittivity and loss tangent of thenanocomposites suggest that the introduced BTphase and interface areas contribute to theimprovement of the dielectric responses.
Meanwhile, the X-ray diffraction patterns andDifferential Scanning Calorimetry (DSC) curvesindicate that the incorporation of ceramicparticles contributes to the decrease of thecrystallite size, the increase of the crystallinity,
and the shift of the crystallization temperature of
the polymer matrix.
Furthermore, the dielectric displacement and energy density of the nanocomposites are significantly
enhanced and an energy density of 3.54 J/cm3 was
obtained under an electric field of 200 MV/m with Fig. 1: Schematic of the fabrication of the
BT/PVDF nanocomposites (a) and energy density of
the BT concentration of 20 vol. %.
the pure polymer and the nanocomposites as a

The results indicate that the introduced ceramic function of the volume fraction of BT (b).
fillers and interface areas have positive influences on
the structure of the polymer matrix and contribute to the enhancement of the dielectric responses
and energy storage properties of the nanocomposites.
.

372

K. Yu, H. Wang, Y. Zhou, Y. Bai, and Y. Niu, “Enhanced dielectric properties of BaTiO3/poly(vinylidene fluoride) nanocomposites for energy storage applications”, J. Appl. Phys., 113, 034105 (2013).

ISAF-P4D-11 ____________________________________________________________________________________________________________________New microfabrication method to reverse micrometricferroelectric domains on lithium niobate wafers for RF
applications
Florent Bassignot1, Emilie Courjon1, Fabien Henrot1, Thomas Baron1, Sylvain Ballandras2
1

FEMTO-ST Institute, 32 avenue de l’observatoire, 25000 Besançon cedex, FRANCE
2
FreC'N'Sys SAS, 18 rue Alain Savary, 25000 Besançon cedex, FRANCE
Email: florent.bassignot@femto-st.fr

The demand of acoustic wave devices in telecom as resonators or filters has generated a strong
innovative activity. These components are usually based on surface or bulk acoustic wave
technologie. Recently, we have investigated the interest of periodically poled transducers (PPTs) on
single crystal 500 µm-thick LiNbO3 Z-cut plates through a new acoustic resonator373. The PPT
consists of two electrically conductive medias embracing a periodically poled ferroelectric layer. Its
fabrication is based on a poling bench which mainly consists of a high voltage amplifier used tosubmit the patterned ferroelectric wafer to an electric field strong enough to invert its native
polarization. The resonance frequency of the new resonator is fixed by the PPT period. In order toanswer to the need of high frequencies sources (RF until X band domain), the PPT period must be
lower to ten microns. For this specification, the PPT fabrication using the classical method byelectric field application is difficult due to the enlargement of the reverse ferroelectric domains
under the electrical insulating layer.
In this work, we present a new microfabrication method allowing to reverse micrometricferroelectric domains by electric field application. As the enlargement of the reverse ferroelectricdomains under the electrical insulting layer depends of the applied electric field value, a technology
based on wafer-bonding and plate thinning techniques has been developped. The method firstly
consists of bonding a 500 µm-thick lithium niobate Z-cut single crystal plate onto a doped siliconwafer, the ferroelectric wafer is then thinned down to a few tens of microns by lapping andpolishing techniques. The resulting composite wafer is finally poled by applying a low electric field.
The fabrication of PPTs exhibiting a poling period of 5 µm has been successfully achieved bymeans of this new microfabrication method on a 50 µm-thick lithium niobate layer bonded on a
doped silicon wafer (Fig. 1). It has been successfully implemented on the new acoustic resonator1
and tested allowing the excitation of elastic waves at frequencies up to 1 GHz (Vφ=6500 m.s-1).

373

F. Bassignot et al., “Acoustic resonator based on periodically poled transducers: Concept and analysis”, J.
Appl. Phys., vol. 111, 064106, 2012.

Fig. 116: SEM view of a 5 µm period device based on a doped silicon plate bonded on a 50 µm-thick lithium
niobate layer. The structure has been etched in a hydrogen fluoride solution in order to observe the domain

alternation.

ISAF-P4D-12 ____________________________________________________________________________________________________________________

BZN Thin-Film Multilayer Capacitors Fabricated at Low
Temperature by Radio Frequency Magnetron Sputtering

Fan He, Saeed Khan, Wei Ren*, Peng Shi, and Xiaoqing Wu
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education &International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049, China* Email: wren@mail.xjtu.edu.cn

In this study, thin film multilayered capacitors (MLCs) composed of amorphous Bi1.5Zn1.0Nb1.5O7(BZN) dielectric layers with internal electrodes were fabricated by radio-frequency (RF) sputtering
at a temperature below 150 C. All BZN thin films were deposited through a set of steel shadow
masks at room temperature and post-annealed at 150 C. XRD pattern and SEM images confirmedthat the BZN dielectric layers used in these MLCs are amorphous and the thickness for each BZN
layer is approximately 200 nm. Metallic Pt and Cu with about 50 nm thick were studied as internal
electrodes, respectively. We fabricated BZN thin film MLCs with different layers. The thin film
MLCs with 5 BZN layers exhibit promising dielectric properties: the relative permittivity of around
60, the dielectric loss of 13% at 10 kHz and a leakage current of 10-4 A at a dc bias electric field of
150 kV/cm. The capacitance density for each dielectric layer is around 300 nF/cm2. The BZN thinfilm MLCs have a potential application on embedded PCBs.

ISAF-P4D-13 ____________________________________________________________________________________________________________________

Piezoelectric thick film sensors: Fabrication and characterization
Florian VERY1, Philippe COMBETTE1, Denis COUDOUEL1, Alain GIANI1, Jean-Yves
FERRANDIS1, Eric ROSENKRANTZ1, Damien FOURMENTEL2
1
IES, Institut d’Electronique du Sud, Université Montpellier2, FRANCE2
CEA Cadarache, DEN/DER/SPEx/LDCI, St Paul lez Durance, FRANCE
The screen printing of piezoelectric offers a wide range of possible applications for the developmentof acoustic sensors and the measurement of small size deformations. Material properties
characterizations of these thick-film PZT resonators are essential for device design and applications.
We measured the electrical properties for different ranges of frequencies and temperature –from
1µHz up to 13MHz between 30 and 400 ° C-. The piezoelectric coefficients d33, d31 and pyroelectric coefficient are also investigated. With this aim, we made various thicknesses of Lead
Zirconate Titanate (PZT) thick films, up to 60 µm by screen printing process. The deposit has beenobtained by superposition of several layers thick of 20 microns. We implement different screen
printing processes –firing and co-firing duration, controlled temperature rate to bring the best
piezoelectric coefficients and acoustic impedance values. We will highlight the use of theses thickfilms in order to characterize both the liquid acoustic properties and the mass determination.

Figure 117 : Screen printed piezo sensor

ISAF-P4D-14 ____________________________________________________________________________________________________________________

Multi-physical numerical modeling of a piezoelectric
loudspeaker for hearing aid applications and experimental
validation
Gustavo C. Martins1, Leonardo Seki1, Júlio A. Cordioli1
1Department of Mechanical Engineering, Federal University of Santa Catarina, Florianópolis, Brazil
Email: gustavo.martins@lva.ufsc.br

Piezoelectric materials are widely used in applications involving miniaturized components. The
application of these materials in hearing aid receivers presents technical and economic advantages
such as reducing the number of parts of the system and its manufacturing cost. The modeling of aminiaturized piezoelectric loudspeaker for hearing aids involves multi-physical models with strong
coupling between the involved physics. In the literature, analytical models of these components canbe found. However, these analytical models usually involve very simple geometries and boundary
conditions. These characteristics restrict the use of such models as a design tool for miniaturized
piezoelectric loudspeaker analysis. This work presents multi-physical numerical models of
miniaturized loudspeaker prototypes. The numerical models were constructed using the Finite
Element Method (FEM). The loudspeakers are composed of a piezoelectric diaphragm coupled tosmall cavities with different depths, and the multi-physical model includes the coupled
piezoelectric, structural and acoustic behaviors of the systems. For the cavity with reduced depth,
thermal and viscous effects on the acoustic propagation are taken in account in the FEM model.
Finally, experimental tests of the piezoelectric diaphragm alone and coupled with the acoustic
cavities are used to validate the multi-physical model.

ISAF-P4D-15 ____________________________________________________________________________________________________________________

Barium-Strontium-Titanate Thin Film Varactors Integrated on
Low-resistivity Silicon and Sapphire Substrates
Hailing Yue1, Dustin Brown1, Guru Subramanyam1, Kevin Leedy2, Charles Cemy2
1

Department of Electrical Engineering, University of Dayton, Dayton, Ohio/The United States
2
Air Force Research Laboratory, Wright Patterson AFB, Dayton, OH/The United States
Email: yueh01@udayton.edu

Barium-Strontium-Titanate(BST) thin film
based ferroelectric varactors are designed
for specific capacitance values at 0V dc bias
on CMOS compatible low-resistivity silicon
substrates and sapphire substrates. The BST
varactor device operation is based on the
nonlinear dielectric tunability of BST thinfilm sandwiched between two metal layers
in an optimized conductor-backed coplanar
waveguide(CBCPW) transmission line
configuration(Fig. 1). The effective varactor
capacitance at 0V dc bias is determined by Fig. 118: 3D view of the standard BST varactor device.
the overlap area between the CPW signal
line in the top metal electrode and a shunt line in the bottom electrode.
Devices with 0V bias effective capacitances ranging from 0.8pF to 4.8pF were designed andfabricated by changing their corresponding overlap areas calculated from the generic parallel–plate
capacitance equation. A schematic model was also utilized to extract the designed and measured
capacitances. The relationship between the sizes of the overlap areas and the extracted capacitancesfrom both electromagnetic and matched schematic models is demonstrated by a reasonableagreement with the experimental measurements from the fabricated devices on low-resistivity
silicon substrates. Following the same procedure, devices with higher 0V capacitances ranging from5 pF to 50pF were also designed and fabricated on sapphire substrate with three variations fromstandard configuration aiming to reduce the parasitic resistance. The experimental results fromthese highly capacitive device and their variations also agrees with the simulation results.

ISAF-P4D-16 ____________________________________________________________________________________________________________________High Energy Density composites Based on Poly (vinylidene fluoride-chlorotrifluoroethylene)
and lanthanum doped lead zirconate titanate stannate antiferroelectric ceramic
Fei Wen, Weimin Xia, Xiaoyong Wei, Zhuo Xu
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education &International Center for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049. P. R. China
Email: wen.1205@stu.xjtu.edu.cn
Abstract
Recently, the investigation of dielectric materials with high energy density for high pulse
capacitors application have attracted considerable attention, especially since the poly(vinylidene
fluoride) (PVDF) based ferroelectric elastomers were reported.374 In an effort to further enhance theenergy storage properties of the fluoro-polymers, several inorganic fillers were introduced into
these fluoro-elastomers as well. At present, the inorganic fillers are most focused on
antiferroelectrics, ferroelectrics, and linear dielectrics. The antiferroelectrics is favorable candidate
because it can be released the total stored charges due to the absence of any remnant polarization.
The lanthanum doped lead zirconate titanate stannate antiferroelectric ceramic(Pb0.97La0.02)(Zr0.65Sn0.25Ti0.10)O3 (PLZST) was used for inorganic fillers. Three series of(PLZST)/P(VDF-CTFE) composites with varied compositions were fabricated via solution castprocess followed by thermally treated in different ways. Quenching the composite samples at lower
temperature could effectively enhance their dielectric constant, breakdown strength as well as theenergy density. The highest energy density (12.1J/cm3) is observed in quenched from 200°C to 195°C with 5 vol% PLZST as shown in table 1, which is much higher than that reported in thecurrent literature. As the PLZST content increasing, the dielectric permittivity and energy density
measured under the same electric field increases. However, the dielectric breakdown strength andthe energy density measured at breakdown strength of the resultant composites decrease as PLZST
content increasing.
TABLE I. Discharged energy density (Ue) of PLZST/P(VDF-CTFE) composites under varied electric field.
PLZST
Ue (J/cm3) of Q100 at
Ue (J/cm3) of Q-94 atUe (J/cm3) of Q-195 atcontent
various E (MV/m)various E (MV/m)various E (MV/m)
vol%
100
200
Eb
100
200
Eb
100
200
Eb
0
0.30
1.17
4.82
0.51
2.06
12.4
0.40
1.69
11.3
5%
0.37
1.38
4.10
0.61
2.42
10.5
0.70
2.77
12.1
10%
0.46
1.81
4.84
0.58
2.32
7.56
0.62
2.47
5.73
15%
0.55
2.26
5.07
0.81
3.11
7.15
0.71
2.58
5.40
20%
0.56
2.22
2.96
0.93
3.11
6.22
0.67
2.80
3.42
25%
0.69
2.47
2.67
0.71
3.26
3.26
1.06
3.60
4.25
30%
0.71
2.18
1.20
2.94
1.09
2.84
40%
0.74
1.41
1.46
2.46
1.35
2.72
“-”denotes the sample is broken under the corresponding electric field.

374

B. Chu, X. Zhou, K. Ren, B. Neese, M. Lin, Q. Wang, F. Bauer, and Q. M. Zhang, “A Dielectric Polymer with HighElectric Energy Density and Fast Discharge Speed”, Science, vol.313, p.334-336, 2006.

ISAF-P4D-17 ____________________________________________________________________________________________________________________

Flexible Piezoelectric Energy Harvesters Fabricated by KNbO 3
Nanowires

Mi-Ri Joung1, Haibo Xu1, Jin-Seong Kim1, In-Tae Seo1, Sahn Nahm1,2, Seok-Jin Yoon3, ChongYun Kang2,3
1

2Department of Materials Science and Engineering, Korea University, Seoul, Korea
Department of Information Technology-Nano Science, Korea University-Korea Institute of
Science and Technology School, Korea University, Seoul, Korea
3
Electronic Materials Center, Korea Institute of Science and Technology, Seoul, Korea
Email: miri0805@korea.ac.kr

Tetragonal KNbO3 (KN) nanowires were formed when the synthesis was carried out at 120oC for 48
h. However, when the fabrication was conducted at high temperatures (≥ 150oC) or at 120oC for along period of time (≥ 72 h), orthorhombic KN nanowires were obtained. Moreover, the KN
nanowires synthesized at 120oC for 60 h showed a morphotropic phase boundary (MPB) structurein which both tetragonal and orthorhombic structures coexisted. A tetragonal KN nanowire
exhibited a d33 value of 137.1 pm/V, which is larger than that of the orthorhombic KN nanowire(104.5 pm/V), probably because of the softening effect of the metal vacancies. The MPB KN
nanowires exhibited a larger d33 value of 146.0 pm/V. Three types of the KN nanowires were mixed
with Polydimethylsiloxane(PDMS) and these mixtures (PDMS-KN) were deposited on the Aucoated Polyimide(PI) substrate. Finally, the Au-coated PI was covered on the PI/Au/PDMS-KN
device to fabricate the piezoelectric energy havrester. In these work, three types of KN piezoelectricenergy harvesters were fabricated and the output power of these harvesters were investigated.
Moreover, the magnitude of their output power was explained based on the structural andpiezoelectric prperties of the KN nanowires.

ISAF-P4D-18 ____________________________________________________________________________________________________________________Polymer Matrix-Based Piezoelectric Composite for Structural
Health Monitoring
Walter Katsumi Sakamoto1, Ricardo Tokio Higuti2, Evelyn Brazoloto Crivelini1, Haroldo Naoyuki
Nagashima1.
1

Departamento de Física e Química, Universidade Estadual Paulista - UNESP, Ilha Solteira, SãoPaulo, Brazil.
2
Departamento de Engenharia Elétrica, Universidade Estadual Paulista - UNESP, Ilha Solteira, SãoPaulo, Brazil.
Email: sakamoto@dfq.feis.unesp.br
Structural health monitoring (SHM) refers to the procedure of assessing the structure conditions
continuously so it is an alternative to conventional nondestructive evaluation (NDE) techniques375.
With the growing developments in sensor technology acoustic emission (AE) technology has been
attracting attention in SHM applications. AE are characterized by waves produced by the suddeninternal stress redistribution caused by the changes in the internal structure, such as fatigue, crack
growth, corrosion, etc. Piezoelectric materials such as Lead Zirconate Titanate (PZT) ceramic havebeen widely used as sensor due to its high electromechanical coupling factor and piezoelectric dcoefficients. Because of the poor mechanical characteristic and the lack in the formability of theceramic, polymer matrix-based piezoelectric composites have been studied in the last decade inorder to obtain better properties in comparison with a single phase material. In this study acomposite film made of polyurethane (PU) and PZT ceramic particles partially recovered withpolyaniline (PAni) was characterized and used as sensor for AE detection. Figure 1 shows the photoof the experiment and the response of the sensor to a pencil lead break simulated AE source
recorded by an oscilloscope. Preliminary results indicate that the presence of a semiconductor
polymer (PAni) recovering the ceramic particles, make the poling process easier and less time
consuming. Also, it is possible to observe that there is a great potential to use such type ofcomposite as sensor for structure health monitoring.

.

375

H-S. Yoon; D. Jung; J-H. Kim, “Lamb wave generation and detection using piezoceramic stack transducers forstructural health monitoring applications, Smart Mater. Struct., 21, 055019 (2012).

Fig. 1. – PZT-PAni/PU composite
surface mounted on aluminum plate.
Pencil lead break was used assimulated AE source.

ISAF-P4D-19 ____________________________________________________________________________________________________________________

Piezoelectricity of New Peptide-Based Materials
Maciej Wojtaś1,2, Andrei Kholkin2
1

Faculty of Chemistry, University of Wroclaw, Wroclaw, Poland
2
CICECO, University of Aveiro, Aveiro, Portugal
Email: m.wojtas@ua.pt

Piezoelectricity is the ability of noncentrosymmetric crystals to produce mechanical stress/strain
under electric field or charge under mechanical stress. This property has long been used in acoustic
transducers, sensors/actuators, piezomotors, and more. Pushed by the technology progress, superiorenergy density, and low energy consumption, piezoelectrics have recently experienced a drastic
miniaturization giving rise to a new direction commonly abbreviated as piezoMEMS (forMicroElectroMechanical Systems).
The new organic and bioorganic materials having significant piezoactivity are indispensible torevolutionize the piezoMEMS. However, as for today, only weak piezoelectric effects in bioorganic materials have been observed.
Therefore, the search for micro- andnanoscale piezoelectric materials has
drawn much attention in the last decades.
We present the new peptide-basedmaterials of interesting physicochemical
properties (including piezoelectricity).
These materials are characterized by thewide variety of structures created giving
opportunity to design and developed newnanoscale devices, to name only a few:
biosensors, piezoMEMS or in drugs
transport/carrier applications.
Figure 119 The example of the peptide-based
nanostructure.

ISAF-P4D-20 ____________________________________________________________________________________________________________________

Evaluation of the performance of a piezoelectric nanowirebased composite microgenerator
Olivier Graton1, Guylaine Poulin-Vittrant2, Louis-Pascal Tran Huu Hue2,3 and Marc Lethiecq2
1
2

GREMAN UMR 7347, 16 rue Pierre et Marie Curie, Tours Cedex2 37071, France
GREMAN UMR 7347, Rue de Chocolaterie, BP 3410, Blois Cedex 41034, France
3
ENIVL, Rue de Chocolaterie, BP 3410, Blois Cedex 41034, France
Email: olivier.graton@univ-tours.fr

Recently, a new generation of piezoelectric micro-harvester based on ZnO nanowires (NWs) has
been developed with promising results1. This kind of generators is made up of arrays of vertically or
laterally aligned NWs wrapped in a polymer matrix. It works in quasi-static regime and thus seems
to be well-adapted to harvest mechanical energy from low frequency natural sources.
In order to estimate the performance of such devices, we have developed a new model of NW-based
microgenerator. If a single ZnO NW can be seen as a one-dimensional piezoelectric nanotransducer,
an array of NWs in a passive polymer matrix is rather comparable to a 1-3 piezocomposite. Thus,
the polymer phase must be taken into account when simulating the mechanical and electricalbehavior of the generator. Since the microgenerator works in quasi-static regime, we consider thecomposite as an effective homogeneous medium whose physical properties are expressed in termsof the volume fraction of ZnO. The equivalent circuit of the microgenerator is then established. As
an application, we have modeled the microgenerator based on a vertical array of NWs presented in1.
Numerical results showed a good agreement withexperimental results given in the cited paper, bothin terms of open-circuit voltage and short-circuitcurrent. We have also studied the impact of thecompositematerialparametersonthemicrogenerator performance. It has been found thatits power density is proportional to the square of
the volume fraction of ZnO (Fig. 1).
This model seems to be well adapted to NWpolymer based micro-harvesters and should be
extended to lateral NWs array configurations.
Finally, by performing an exhaustive parametricstudy, this equivalent circuit could be a valuable Fig. 120: Computed power density of thetool for both design and performance prediction of microgenerator excited by a low frequency (5Hz) compressive stress.
NWs based microgenerators.
1. S. Xu. et al., “Self-powered nanowire devices”, Nat.
Nanotechnol., vol. 5, p. 366-373, 2010.

ISAF-P4D-21 ____________________________________________________________________________________________________________________

Piezoelectric PZT Fiber Composite as a Low Frequency
Vibration Sensor
Qian Chen1, Yingying Sun1, Lifeng Qin2, Hao Hue2, and Qing-Ming Wang1
1

Department of Mechanical Engineering and Materials Science, University of Pittsburgh,
Pittsburgh, PA, USA. Email: qiw4@pitt.edu
2

Xiamen University, Xiamen 361005, P. R. China

The recently developed macro fiber composites (MFCs) with in-plane aligned PZT fibers
embedded in polymeric thick films combine the excellent piezoelectric property of PZT fibers andthe flexibility of polymer, which are suitable for many sensor and actuator applications376,2. In thispaper, we present both theoretical and experimental
studies of a low frequency vibration sensor using the
PZT fiber composite in a simple cantilever structure.
The constitutive relations for the in-plane aligned
PZT fiber composite with interdigitated transducer(IDT) electrodes were derived and an analyticalmodel for calculating the material effective
parameters was obtained. The global properties of
PZT fiber composite were then calculated and Fig. 121: The schematic of the MFCs unimorph
vibration sensor.
validated with results obtained by mixing rule anddata from literatures. These global parameters of the
PZT fiber composite were then substituted into the
lumped and distributed parameter models for
cantilevered piezoelectric unimorph vibration sensors
to predict the voltage output sensitivity and frequency
response. Finally, experimental studies were carriedout and the predicted performance of the low
frequency vibration sensor agrees well with theexperimental results. Shown in Fig. 1 is theexperimentally schematic of the PZT fiber composite
cantilever tested as a low frequency vibration sensor; Fig. 122: Experimental and calculation results of theand Fig. 2 is the experimental and calculation results frequency response of output voltage per unitof the frequency response of output voltage per unit vibration amplitude for a PZT MFCs unimorph
vibration amplitude for a MFCs unimorph. With
excellent flexibility, tailorable elastic, dielectric and piezoelectric properties, and large time
constant, the PZT fiber composite works well as vibration sensor that has very low resonant
frequency.

376

A. Bent, and N. W. Hagood, “Piezoelectric fiber composites with interdigitated electrodes,” J. Intell. Mater. Syst.
Struct., vol. 8, no. 11, pp. 903-919, 1997.
2

Deraemaeker, H. Nasser, A. Benjeddou, and A. Preumont, “Mixing rules for the piezoelectric properties of macro
fiber composites,” J. Intell. Mater. Syst. Struct., vol. 20, no. 12, pp. 1475-1482, 2009.

ISAF-P4D-22 ____________________________________________________________________________________________________________________

3D Sensor Based on Polyvinylidene Fluoride (PVDF)
Yung Ting, Hariyanto Gunawan, Jain-Zhi Zhong and Kai-Jian Zheng
Department of Mechanical Engineering, Chung Yuan Christian University, Chung Li, Taiwan
Email: yung@cycu.edu.tw
Polyvinylidene Fluoride (PVDF) material is one of electroactive material which has high sensitivity
and good response. In this study, it is attempted to build a 3D sensor based on polyvinylidene
fluoride (PVDF) material. For existing 3D sensors, they are usually constructed with three layers.
Each layer is in charge of the response of one axis individually. Distinguish from these sensors, a
new developed 3D sensor is designed with only one layer that can measure the response of all threeaxis simultaneously. Thin, flexible, and high sensitivity are the advantages of this 3D sensor. An
example of 40x40x0.01mm of stretched PVDF is built. Combination of polarization in thickness
and planar direction are applied in order to produce 3D sensor. The piezoelectric constant of PVDF
is measured by using FTIR and DSC characterization and voltage response of PVDF is measured
using oscilloscope. Fig. 1 shows the designed 3D sensor. As shown, (X1,X2), (Y1,Y2), (Z) represent
the measure along the X, Y, and Z axis respectively. To measure the voltage response of 3D sensor,
vertical and horizontal force of about 1.96 N is applied to the sample respectively as shown in Fig.
2. Voltage response of 3D sensor is measured and shown in Fig 3a and Fig 3b for the case of
applied vertical and horizontal force respectively. As seen in Fig 3, voltage response in X, Y, Z-axis
can be measured simultaneously while a force is applied. Regarding some other importantcharacteristics, measurement data and discussion will also be presented and addressed later.

Fig. 1. Design of 3D Sensor.

(a)Fig. 2. Scheme of Applying Force(b)

Fig. 3 Voltage response of 3D sensor when applying: (a) Vertical force, (b) Horizontal force

ISAF-P4D-23 ____________________________________________________________________________________________________________________

Bi2(Zn2/3Nb4/3)O7/Epoxy composites with enhanced dielectric
properties for embedded capacitor applications
Yuanyuan Bai 1, Hong Wang1, Feng Xiang1, Yu Ke1, Yujuan Niu1
1

Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education,
Xi’an Jiaotong University, Xi’an 710049, China
Email: bai.yuanyuan@stu.xjtu.edu.cn

In the present work, Bi2(Zn2/3Nb4/3)O7 (BZN) ceramic filled epoxy based composites were preparedusing ball-milling mixing followed by solution casting process. The BZN/Epoxy composite exhibits
enhanced dielectric permittivity and reduced loss tangent in the microwave frequency range from 5
GHz to 20 GHz.
The dielectric permittivity and loss tangent of the BZN/Epoxy composites were investigated as afunction of the volume fraction of BZN powders. The dielectric permittivity and loss tangent of thecomposite with 40% volume fraction of filler loading was 11.6 and 0.02, respectively, at 5 GHz.
The results indicated that the incorporation of pyrochlore BZN ceramic powders could greatly
enhance the dielectric permittivity and decrease the loss tangent of the BZN/Epoxy composite,making the BZN/Epoxy composite a desirable candidate for embedded capacitor applications. In
addition, the measured dielectric constant and loss factor were in well consistence with the effective
medium theory and the parallel formula, respectively.
Furthermore, the comparison of the dielectric properties between the composite with BZN particles
milled by regular ball-milling and that with BZN particles milled by high-energy ball-millingindicated that high-energy ball-milling contributed to enhance the dielectric permittivity of thecomposite at low frequency range.

ISAF-P4D-24 ____________________________________________________________________________________________________________________

Electrocaloric properties of 0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3
ceramics
Marko Vrabelj1, 2, Hana Uršič1, 3, Brigita Rožič1, 3, Zdravko Kutnjak2, 4, Silvo Drnovšek1, 3, Barbara
Malič1, 2
1Electronic Ceramics Department, Jožef Stefan Institute, Ljubljana, Slovenia
2Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
3
Centre of Excellence NAMASTE, Ljubljana, Slovenia
4
Condensed Matter Physics Department, Jožef Stefan Institute, Ljubljana, Slovenia
Email: marko.vrabelj@ijs.si
The electrocaloric (EC) effect is a conversion of electrical energy to heat and may be defined as anadiabatic and reversible temperature change that occurs in a polar material upon external electricfield. The aim of our work was to prepare 0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 (0.7PMN–0.3PT)
ceramics and to study the EC temperature change (T) vs. applied electric field and temperature.
For the synthesis of the 0.7PMN–0.3PT bulk ceramics, PbO, MgO, TiO2 and Nb2O5 were used. The
homogenized, stoichiometric powder mixtures were mechanochemically activated in a high-energy
planetary mill. The synthesized powders were milled in an attrition mill in isopropanol. The powder
compacts were sintered at 1200 °C for 2 h in a double alumina crucible in the packing powder. The
ceramics had relative density 97 % and the grain size of (1 ± 0.5) m.
3,0
4

2,5

2,5x10E (kV/cm)

2
7,5
30
60
90

2,0
1,5

4

2,0x10

4

1,5x101,0(EDC=0)EC (K)In order to study EC effect by direct
approach, a high resolution calorimeter wasused. The observed magnitudes of the EC
effect confirm the existence of the large
effect in this material. A characteristic peakof T as a function of the electric field isobserved near the critical point as shown in
Fig. 1, where T is 2.7 K at 90 kV/cm and
430 °C.377

41,0x100,53

5,0x10

0,0
320

340

360

380

400

420

0,0
440

T (K)

Acknowledgments:

Fig. 123: EC temperature change T of 0.7PMN–
0.3PT ceramics as a function of temperature forseveral amplitudes of the electric field. Triangles
1
denote the dielectric constant.

The contribution of Prof. Marija Kosec who passed away in December 2012 is gratefully
acknowledged. The authors would like thank Jena Cilenšek, Brigita Kmet and David Žehelj for377

B. Rožič, M. Kosec, H. Uršič, J. Holc, B. Malič, Q. M. Zhang, R. Blinc, R. Pirc, Z. Kutnjak, Influence of the criticalpoint on the electrocaloric response of relaxor ferroelectrics, J. Appl. Phys., vol. 110, p. 064118 1 -5, 2011.

their help with the experimental work and the Slovenian Research Agency for financial support(research program P2-0105 and doctoral program PR-05025).

ISAF-P4D-25 ____________________________________________________________________________________________________________________

Experimental and numerical characterization of a hearing aid
prototype microphone with piezoelectric membrane
Israel Pereira1, Gustavo Martins1, Júlio A. Cordioli1,
1

Mechanical Engineer Department, Federal University of Santa Catarina, Florianópolis, SC/Brazil
Email: israel.pereira@live.com

The microphone is an important component of hearing aids. They are responsible for converting
acoustic energy into electrical energy and a proper design of this component is critical to obtain
good results in everyday life of hearing aids users. Electret microphones are the current first choicein this kind of application but alternative designs of microphones are also been considered.
Piezoelectric microphones have numerous advantages over electrec microphones, like the reduced
number of components, very flat frequency response and high resistance to mechanical shocks.
Furthermore, piezoelectric microphones can have very simple constructions, ensuring reduced
manufacturing costs. The main difficult of using this type of microphone in hearing aids is its
typical lower sensitivity when comparing to electret ones. Many efforts are in progress to increase
the sensitivity of piezoelectric microphones and one of the most important tools to achieve that is aproper numerical modeling of these transducers.
This paper presents the numerical modeling of a piezoelectric prototype used as a microphone. The
transducer is modeled with different variations of the Finite Element Method (FEM), including the
traditional coupled Acoustic-Structure FEM and a modified formulation that includes the effects ofviscothermal losses in the model. Also, an analysis of the load applied to the piezoelectric model isperformed in order to obtain realistic results.
The model is validated with experimental results and its sensitivity level is compared withcommercial microphones. After the validation, the numerical model can be used to optimize thepiezoelectric microphone properties in order to fulfill the requirements for hearing aids.

ISAF-P4D-26 ____________________________________________________________________________________________________________________A Flexible Piezoelectric Power Generator Based on Selfassembled, Highly <001> Oriented BaTiO3 Micro Platelet Thin
Layer by an Interfacial Strategy
Hao Xue†, Donghua Fan†, Zhaoxian Xiong†, Qing-Ming, Wang,‡†Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen
361005, P. R. China. Email: qiw4@pitt.edu‡

Department of Mechanical Engineering and Materials Science, University of Pittsburgh,
Pittsburgh, PA, 15261, USA

Energy harvesting technologies that convert
existing sources of energies, such as mechanical energy
from the natural sources of wind, ocean waves,vibration of structure, and human or animal movements
into electrical energy, is attracting tremendous interestin the scientific community378,2. In this paper, we
present a flexible piezoelectric generator based on selfassembled, highly <001> oriented BaTiO3 microplatelet like thin film layer embedded in soft polymer
matrix. Perovskite ferroelectric materials often exhibit
evidently anisotropic characteristics on piezoelectricity.
We successfully controlled the morphology andorientations of BaTiO3 micro platelet like crystals
through a chemical processing, and subsequently
obtained the highly <001> oriented BaTiO3 by a facileinterfacial self-assembled approach. The assembled
BaTiO3 was packaged with PDMS and coated with top
and bottom electrodes. The composite films were poledby an electric field at room temperature, and thenattached on a flexible substrate to form a piezoelectric
generator. Fig.1 shows the obtained BaTiO3 microplatelets. By comparison with random oriented BaTiO3
based piezoelectric generator, this <001> oriented
BaTiO3 film based piezoelectric produced evidently
higher output voltage and current under dynamic
periodic load by applying a harmonic force. The <001>oriented BaTiO3 film based piezoelectric generator
were using to harvest the energy of human body
movement and the generator fixed on finger provided
the highest open circuit output voltage of 0.53v andShort-circuit current of 70nA, respectively.

378

Fig. 124: a) Illustration of the self-assembly of the BaTiO3
micro-platelets at the hexane/water interface and the transfer
procedure. b)The XRD pattern of samples: (i) BaTiO 3 platelike particles, (iv) BaTiO3 self assembled film by aninterfacial strategy; c) and d)SEM images of the highlyoriented BaTiO3 film transferred onto plastic substrate.

Fig. 125: (a) Schematics of the cross-sectional structure of<001> oriented BaTiO3 film based piezoelectric generator
bended by finger movement; (b) The open circuit output
voltage generated from <001> oriented BaTiO3 film based
piezoelectric generator bended by finger movement; (c) The
short circuit output current generated from <001> oriented
BaTiO3 film based piezoelectric generator bended byfinger movement.

Yang, R. S., Qin, Y., Dai, L. M. & Wang, Z. L. Power generation with laterally packaged piezoelectric fine wires.
Nat Nanotechnol 4, 34-39 (2009).
2

Choi, D. et al. Fully Rollable Transparent Nanogenerators Based on Graphene Electrodes. Adv Mater 22, 2187 (2010).

ISAF-P4D-27 ____________________________________________________________________________________________________________________

Photocurrent Characteristics of PbTiO3/TiO2 Heterostructure
Nanotubes
using Anodic TiO2 Nanotubes
Sung Sik Won*, Chang Won Ahn and Ill Won Kim
Department of Physics and Energy Harvest-Storage Research Center,
University of Ulsan, Ulsan 680-749, South Korea
When electrically poled ferroelectric materials are illuminated by light beam, photo-voltage andphoto-current can be generated due to the separation of photoinduced electrons and holes by its
internal electric field. Such photovoltaic phenomena in the ferroelectric thin films exhibit potential
applications for realizing remote control and wireless energy transfer in microelectromechanicalsystem (MEMS) devices. In this study, we have grown TiO2 nanotube layers on sputter-deposited
Ti thin films by glycerol/NH4F electrolytes. PbTiO3/TiO2 heterostructure nanotube was obtained bydeposited Pb into the highly ordered TiO2 nanotube layers and thermally annealed in the oxygenambient. The crystalline structure and surface morphology of PbTiO3/TiO2 heterostructure
nanotubes were investigated by XRD and FE-SEM studies. Compared with pure TiO2 nanotube
array, the PbTiO3/TiO2 heterostructures exhibited enhanced photocurrent under UV lightirradiation.

ISAF-P4D-28 ____________________________________________________________________________________________________________________

Planar acoustic metamaterials with the active control of
acoustic impedance using a piezoelectric composite actuator
K. Nováková1, P. Mokrý2, J. Václavík2, P. Márton2, M. Černík2, P. Psota1, R. Doleček1, V. Lédl1
1
Regional Centre for Special Optics and Optoelectronic Systems (TOPTEC),
Sobotecká 1660, CZ-51101 Turnov, Czech Republic
2
Institute of Mechatronics and Computer Engineering, Technical University of Liberec
Studentská 2, Liberec I, CZ-46117 Czech Republic
Email: novakova@ipp.cas.cz
Noise and vibrations affect our lives and the intensity of generated noise and vibrations has become
an important parameter indicating the quality of the environment. One of the major noise sources in
our homes and offices are vibrations of windows and glazed facades. Propagation of acoustic
energy in an acoustic medium and the reflection of noise at interfaces of two different media arecontrolled by a physical property called the acoustic impedance Z. By specified tuning the acoustic
impedance of the planar structure at the interface of acoustic media one can achieve devices such as
perfectly absorbing surfaces or perfect sound shields. It is clear that realization of two
aforementioned devices usually requires such values of the acoustic impedance that are notobserved in nature. Such systems are generally called acoustic metamaterials.
In the Paper, there are presented methods for a
precise active control of the acoustic impedanceof large planar structures, e.g glass plates orshells, by means of distributed flexible
piezoelectric composite actuators which areconnected to passive or active electronic shuntcircuits. Design of tunable acoustic metamaterials
is realized using Finite Element Method
simulations and their acoustic properties areevaluated using acoustic transmission loss
measurements (Fig. 1). Static and dynamic
displacements of the metamerials produced byelectric voltage are measured using Digital
Fig. 126: Acoustic transmission loss measurement
Holographic Interferometry. We believe that
setup. Electronically tunable acoustic metamaterial
deep understanding of presented systems should
vibrates due to the incident acoustic wave andresult in future applications that improve thetransmits one part of the wave to the other side.
quality of everyday life. This work was supported Both acoustic pressures and vibration amplitude areby Czech Science Foundation Project No.:measured and the acoustic transmission loss is
GACR 13-10365S.
computed.

ISAF-P4D-29 ____________________________________________________________________________________________________________________

Stress and Temperature Dependent Properties of Single
Crystal Piezoelectric Materials and Devices
D.C. Markley1, R.J. Meyer, Jr.1, Z. G. Lowe1, N.P. Sherlock1, and P. Mosbah2
Applied Research Laboratory, The Pennsylvania State University, State College, PA USA
2
Department of Acoustics, Institut Supérieur d’Electronique et du Numérique, Lille, France
1

Email: rmeyer@psu.edu
Work has been done to understand the stress and temperature dependent properties of the active
materials used in SONAR transducers. Increased power and duty cycle demands push these devices
closer to their stress and thermal limits. Demanding environmental conditions make predicting
performance difficult due to changes in material properties. New single crystal piezo-electrics havelarger degrees of non-linearity in both stress and temperature than typical ceramics, such as PZT-8.
This presentation addresses measurement results obtained in experiments at the Applied ResearchLaboratory to determine the effects of the dynamic and static stress, elevated temperatures, and highelectric fields on material properties and device behavior to provide feedback and validation of the
new fully non-linear solution procedure in the ATILA finite element program. Dynamic stress andstrain measurements were made on unconstrained 33-mode bar samples for PZT 8 and PZT 4
ceramics and single crystals of PMNT, PIMNT and Mn doped PIMNT. Mechanical prestress andthermal effects were determined using symmetrically loaded “dumbbell” transducers. An Agilent
4294A Impedance Analyzer was used for small signal measurements of complex impedance andcapacitance to calculate mechanical and dielectric losses. The LDV was used to obtain the effective
d33 of the entire device by measuring displacement at the face of the end mass. A status of the
ATILA++ finite element code will also be provided.
90
PMN-32%PT

80

5

PIMNT

70
0

PZT8

60

% ∆ KT33% ∆ Coupling - k (eff)

10

-5
-10
-15

40

PMN-32%PT

30

PIMNT

20

PZT8

10

-20

0

50

10

20

30

Preload Level (MPa)

40

0
0

10

20

30

40

Preload Level (MPa)Fig.1 Measured small signal changes in effective coupling coefficient and dielectric constantplotted as a function of increasing static preload on dumbbell style transducers samples.

ISAF-P4D-30 ____________________________________________________________________________________________________________________

Piezoelectric polymer multilayers on flexible substrate forenergy harvesting
Lei Zhang, Sharon Su Yin Oh, Ting Chong Wong, Chin Yaw Tan and Kui Yao
Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology andResearch), 3 Research Link, Singapore 117602
Email: k-yao@imre.a-star.edu.sg
Piezoelectric materials possess inherent functions of converting mechanical energy into electricalenergy and they are competitive candidates for harvesting mechanical energy from ambientenvironments. One of major disadvantages of piezoelectric materials, particularly piezoelectric
polymers, for energy harvesting is the low current output with high voltage magnitude due to thehigh impedance of piezoelectric materials. The high impedance of piezoelectric materials also
affects the energy output to a typical external load as a result of impedance mismatch. Adoption ofpiezoelectric multilayer structure is an effective method to overcome this issue, particularly for
piezoelectric polymer materials, by providing reduced impedance, increased current output andadjustable impedance for matching the external load impedance.
In this work, piezoelectric polymer multilayer structure is fabricated on flexible substrate andoperates in bending mode for energy harvesting. Analytical and numerical models are developed tounderstand the effect of material parameters which are critical to the energy harvesting performanceof the piezoelectric multilayer structure on flexible substrate. The relationship among the maximum
output power of the piezoelectric multilayer on flexible substrate, the piezoelectric coefficient andthe dielectric permittivity is established. It is also found that the thickness of the internal electrodesof piezoelectric multilayer significantly affects the electric energy generation in the bending mode.
The effect of impedance matching is clearly illustrated with comparison between a piezoelectric
multilayer and a piezoelectric single layer on the same flexible substrate for bending-mode energy
harvesting. Dramatic improvement on energy output is shown for a 22-layer P(VDF-TrFE)
multilayer structure on flexible substrate compared to that of a single-layer of the similar
configuration with the load resistance range of 25 Ω to 25 kΩ. A 10-layer P(VDF-TrFE)-based
multilayer structure is fabricated by solution coating process on flexible aluminum substrate withmultiple thin layer of internal metal electrodes prepared by physical vapor deposition method. The
experimental results of energy output is evaluated with electrical loading, which indicates that theenergy generated is adequate for many low power electronics.

ISAF-P4D-31 ____________________________________________________________________________________________________________________

Photovoltaic effect of Bi-layered (Na0.82K0.18)0.5Bi4.5Ti4O15 thin films
with different Pt and ITO top electrodes

Won Seok Woo, Sung Sik Won, Chang Won Ahn, Song A Chae, and Ill Won Kim*
Department of Physics and Energy Harvest-Storage Research Center,
University of Ulsan, Ulsan 680-749, S. Korea*E-mail: kimiw@mail.ulsan.ac.kr

Recently, the photovoltaic of the ferroelectric materials, such as Pb(Zr,Ti)O3 (PZT), BiFeO3(BFO), and BaTiO3 family, has become a research focus because it favors device miniaturizationand exhibits ultraviolet (UV) regions with the potential applications for optical microsensing andmicroactuation in microelectromeachanical systems (MEMS).
We have deposited (Na0.82K0.18)0.5Bi4.5Ti4O15 [NKBiT15] ferroelectric thin films by chemicalsolution deposition method and investigated photovoltaic behavior with different top electrodes ofPt and ITO sandwiched Bi- layered structure. The observed photocurrent of NKBiT15 films
strongly depends on the wavelength of incident light beam. Maximum photocurrent of
ITO/NKBiT15/Pt was obtained -27.75 nA/cm2 at 352 nm and the band gap energy of NKBiT15 thinfilms was 3.52 eV. The maximum power conversion efficiency for Pt/NKBiT15/Pt and
ITO/NKBiT15/Pt capacitors are 0.010 and 0.035 % at the incident light beam intensity of 300
mW/m2. The power conversion efficiency of ITO top electrode capacitor is 3.5 times larger thanthat of the Pt top electrode capacitor.

Figure show the typical photocurrent density of NKBiT15 thin films with top-electrodes (Ptand ITO) in poled-up state at wavelength of incident light beam from 300 to 500 nm. The inset of
figure exhibits a schematic diagram of the experimental setup with poled up state.

ISAF-P4D-32 ____________________________________________________________________________________________________________________

Lead free piezoelectric AD layer for micro actuator
Jun Akedo*, Jae-Hyuk Park, and Muneyasu Suzuki
National Institute of Advanced Industrial Science and Technology (AIST) 1-2-1 Namiki, Tsukuba
305-8564 Japan

High performance micro optical scanner with wide scanning angle, high speed scanningand large mirror size is strongly demanded for laser projection system and human detective
sensor, which are expected huge market as piezoelectric actuator in the world. We
demonstrate the lamb wave resonant optical scanning devices actuated by piezoelectric AD
film and report their temperature properties and durability. Metal-based structure wasintroduced to reduce the production cost and to improve the optical scanning performance,
simultaneously. The optical scanner with large mirror size of 1～5 mm square as well as
high scanning angle of over 90 degree were fabricated. A high optical scanning angle (over60 ˚) and high resonant frequency (over 30kHz) were achieved in ambient air without
vacuum packaging. The resonant frequency and scanning angle of scanner were not change
during life test for over 50,000 hours. In this report, BTO thick film as a lead freepiezoelectric material was prepared by aerosol deposition (AD) method for fabrication of
scanner devices. Piezoelectric d31 of BTO-AD film was approximately -138 pm/V. Also,
the performance of optical scanner driven by AD-BTO thick film was compared with thatby BTO bulk material and AD-PZT thick film. As the results, AD-BTO film can be used topractical applications.

ISAF-P4D-33 ____________________________________________________________________________________________________________________

BiFeO3 Thin Films for Photocatalytic Water Splitting
Wei Ji1,2, Kui Yao1*, Yee Fun Lim1 and Yung C. Liang2
1

Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science,
Technology and Research), 3 Research Link, Singapore 117602
2
Department of Electrical and Computer Engineering, National University of Singapore, Kent
Ridge, Singapore 119260*Email: k-yao@imre.a-star.edu.sg

Photoelectrolysis of water into hydrogen and oxygen is an attractive way to harvest the solar
energy. It converts the solar energy into chemical energy, which is much easier to store thanelectricity. Semiconductor metal oxides have been widely used as photoanodes in photoelectrolytic
cells due to their electrochemical stability. An ideal photoelectrolytic cell should be able to drive
both the hydrogen and the oxygen evolutions without any external bias. However, the conduction
bands in most of the oxides studied so far are too positive to drive the hydrogen evolution. Many ofthem also have a wide bandgap larger than 3 eV. Consequently, they are not able to absorb thevisible region of the solar spectrum. New suitable materials are desired to achieve unassisted water
splitting.
Ferroelectric BiFeO3 (BFO) has a direct bandgap of about 2.7 eV. Previous studies havedemonstrated its catalytic effects for water splitting under visible light379. However, the ferroelectric
properties of BFO have not been explored in all these earlier reports. As has been shown in ourearlier works, ferroelectric polarizations can significantly affect the photovoltaic (PV) process inepitaxial BFO thin films. The photocurrent direction can be switched by poling the BFO films in
different directions380. This suggests that the ferroelectric polarization can be used to enhance thecatalytic properties. In this work, we studied the photoelectrolytic water splitting reaction in highquality epitaxial BFO films. Significant anodic current is observed. The onset of the anodic
photocurrent is at 0.210 V for the 223-nm-thick films. This is shifted to -0.036 VAg/AgCl in the 112nm-thick films. The thinner films minimize Ohmic losses and lead to the cathodic shift of thephotocurrent onset. Furthermore, XPS measurements show that the band edges of BFO straddle thewater redox levels. By considering both the energy band positions and the ferroelectric properties,
we propose that BFO can potentially be used to achieve unassisted water splitting in a monolithic
cell.

379

F. Gao, et. al., "Visible-light photocatalytic properties of weak magnetic BiFeO 3 nanoparticls", Adv. Mater., vol. 19,
p. 2889-2892, 2007. J. Deng, et. al., “Bismuth iron oxide nanoparticles as photocatalyst for solar hydrogen generationfrom water”, J. Fund. Renew. Energ., vol. 1, p. 1-10, 2011.
380

W. Ji, et. al., “Bulk photovoltaic effect at visible wavelength in epitaxial ferroelectric BiFeO 3 thin films”, Adv.
Mater., vol. 22, p. 1763-1766, 2010.

ISAF-P4D-34 ____________________________________________________________________________________________________________________

Actuator for precision positioning based on single crystalline
lithium niobate
Ilya Kubasov1, Mikhail Malinkovich1, Aleksander Bykov1, Sedrak Grigoryan1
1

National University of Science and Technology "MISiS", Moscow, Russian Federation
Email: kubasov.ilya@gmail.com

Bimorphs are widely used in actuators designed for precise positioning. Usually they are made oflead zirconate-titanate (Pb(ZrxTi1-x,)O3, PZT) piezoelectric ceramics because of its highpiezoelectric coefficients values and high electromechanical conversion coefficient. At the sametime PZT ceramics have low Curie temperature, high hysteresis, considerable temperaturedependence of the piezoelectric modules, and creep. This disadvantages limit usage of the PZTmade bimorphs and also make additional scanners calibration necessary.
In our previous work the ability to use single crystalline lithium niobate (LN) in the devices for
precise displacement has been considered381. To realize bimorph structure it’s necessary to form
two domains with the opposite orientation of spontaneous polarization vector in a crystal plate. The
bimorph based on LN single crystal has stability in wide temperature range due to Tc about 1200
°C, the absence of hysteresis and creep.
In this study bimorphs were made of single crystal LN plates by using non-uniform thermal field.
Magnetron sputtering was used to make gold electrodes on the bimorph surface. Cantilevered
bending displacements of the 6 cm LN bimorph were ≈±20 μm in the voltage within ±300 V. Single
crystal LN bimorph actuators can be used for exact positioning in probe microscope techniques, forlaser resonators adjustment and as wave guides with exact variable geometrical characteristics.

381

Antipov V.V., Bykov A.S., Malinkovich M.D., Parkhomenko Y.N., “Formation of bidomain structure in lithium
niobate single crystals by electrothermal method”, Ferroelectrics, vol. 374, p. 701–708, 2008.

ISAF-P4D-35 ____________________________________________________________________________________________________________________NUMERICAL SIMULATION ANALYSIS FOR A NOVEL SHAPESOF PIEZOLECTRIC COUPLED WITH TUBE TO INCREASE THE
RADIAL DISPLACEMENT
Yung Ting, Tzung-Shiuan Tsai, Amelia Sugondo and Yen-Lung Lee
Department of Mechanical Engineering, Chung Yuan Christian University, 200, Chung Pei Rd. Chung Li, Taiwan 32023, ROC
Email:yung@cycu.edu.tw
In this paper, piezoelectric actuators that constructed with a ring or several equal sectional type of piezoelectric
ceramics attached to a thin tube are designed. The generated amplitude in the radial vibration of tube and othercharacteristics is investigated. Finite element method (FEM) is used to analyze the mode shape, resonance frequency andamplitude. The analytical and experimental results show a good agreement. From the results, there is no significant differenceof the resonance frequency between the ring-type and sectional-type ceramic actuators. However, the sectional-type one isoable to generate more radial amplitude. In particular, the sectional-type ceramic actuator with arc 60 and with equalclearance between the neighboring actuators performs the best.
Key words: piezoelectric tube, piece-by-piece piezoelectric, radially polarization, amplitude

Design of Piezoelectric Actuator
A.

Resonance Frequency
For a general tube structure, resonance frequency
can be calculated by fr= C/2L where fr is theresonance frequency, L is the length of the device,
and C is the speed of sound. It indicates longer lengthof the structure would reduce the resonancefrequency.
B. Vibration Amplitude
Piezoelectric actuator is mounted on the tube as
illustrated in Figure 1. Two types of piezoelectric
actuators, ring and sectional, are depicted in Figure 2.
A ring type piezoelectric actuator encircled the tube
with no clearance is shown in Figure 2(a), named
TYPE I. Two cases, with arc 120o and 60o of eachsection of piezoelectric actuator with equivalent
clearance in between the actuators for the sectional
type are illustrated in Figure 2(b) and 2(c), named
TYPE II and TYPE III respectively. All the ring andsectional types of piezoelectric actuators are made of
PZT-5A higher piezoelectric coefficient d31 and d33 incomparison with PZT-4 at room temperature. The
tube is made of stainless steel because of high tensile
strength as well as elastic limit that is suitable forhigh power ultrasound design.

Simulation and Experiment Result
Note that, mode shape of tube with half wavelength isthe design purpose. Using ANSYS, an example ofappropriate mode shape is found and deformation
with applied voltage of 50V is shown in Figure 3. As
expected, resonance frequency decreases when thelength of the tube increases. Also, resonancefrequency is inversely proportional to the length of
the rube. The first mode of simple axisymmetricdeformation generating half wave is chosen to
determine the resonance frequency by the modal
analysis. Harmonic analysis is used to examine thevibration amplitude at the chosen resonancefrequency. Figure 4 shows the harmonic simulationand experiment results employed with, for example
50V and 150V. The simulation results show that
amplitude of radial vibration of the tube is very small
for the ring type (TYPE I) but quite large for thesectional type. Compared to the amplitude of TYPE I,
TYPE II is about one thousand times, and TYPE III isabout twenty thousand times. As seen, amplitude of
TYPE I presents with very small difference as tube
length is changed, and amplitude of TYPE II isvarying, and, amplitude of TYPE III is increased for
longer tube but there is a maximum value for thelength of about 47.5mm.

Fig. 1 Tube encircled with piezoelectric actuator
∘
60

∘

60∘

120∘

60

Fig. 2. Type and structure implementation of piezoelectric
actuator: (a) Ring-type piezoelectric actuator encircles
the tube, (b) Sectional-type (120o) piezoelectric actuator,(c) Sectional-type (60o) piezoelectric actuator

Fig. 3. Amplitude for thelength of tube 50 mm

Fig. 4. Amplitude vs. Length
for Ring and Sectional type

ISAF-P4D-36 ___________________________________________________________________________________________________________________

Using d14 FOR A New Wedge-Type Piezoelectric Motor
Yung Ting, Yun-Jui Shieh, Bing-Kuan Hou, Chin-CHih Yeh, Chih-Hao Lin
yung@cycu.edu.tw
Different from the usually designed ceramic actuators using d33 or d15, ceramics d14 is selected tobuild a high speed piezoelectric motor. Since the d14 has good merits of polarization, it will be different
from d15, for example, that needs to increase the thickness along the polarization direction for the
purpose of generating more speed and force output. Therefore, using d14 has the advantage of lower
driving voltage required, and only by increasing the length can to achieve the target of obtaining highspeed and large torque. Ceramics S-6 with high quality factor greater than that of ceramics PZT-8 isused for design of high speed wedge-type motor. Entire surface is fully in contact with the driven
platform or stage.
Analytical simulation in ANSYS and experiment are carried out to investigate the resonancefrequency and vibration mode shape as well as amplitude. Both results have close approximation. For asingle piece of a built sample actuator with 150V applied voltage, it is able to generate vertical andtransverse vibration amplitude of about 0.4µm and 2.0µm respectively. Associated with appropriate
mechanism and assembly work as well as employed with an appropriate signal, the maximum linear
speed is measured about 150mm/sec. As expected, with larger length or structural integration of more
pieces in a series, higher speed would be achieved.
Keywords: wedge-type piezoelectric motor, d14 and d15 ceramics.

3

Driving
ElectrodePoling axis
6

V

2

Polariz
ation
directio
n

5

1

4

Fig. 1 Ceramics
Fig. 2 Polarization
construction
and motion of d14
and polingFig. 3 Motion profile

Fig. 4 Motor integrated
with stageISAF-P4D-37 ___________________________________________________________________________________________________________________

Electrocaloric properties in relaxor ferroelectric PMN-PT
systemJani Peräntie1, Hamel Tailor2, Juha Hagberg1, Heli Jantunen1, and Zuo-Guang Ye2
1

Microelectronics and Materials Physics Laboratories, University of Oulu, P.O.Box 4500, 90014 Oulu,
Finland2
Department of Chemistry & 4D LABS, Simon Fraser University, Burnaby, BC, V5A 1S6,
CanadaEmail: jani@ee.oulu.fi

Various ferroic materials show large caloric effects, such as magneto- and electrocaloric effects, which
can be induced reversibly by different external fields to achieve solid-state cooling cycles382. Due to new
findings383,384 the electrocaloric effect has regained attraction for a potential application in a newgeneration of solid-state cooling devices capable of challenging some existing refrigeration solutions. In
particular, previous electrocaloric results on polymers and oxides have shown that relaxor ferroelectrics
exhibit some interesting and enhanced electrocaloric properties. However, a lack of direct measurement
data on the electrocaloric effect largely restricts ourunderstanding of its behavior and properties.
The Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) relaxor
ferroelectric solid-solution has been one of the moststudied electrocaloric systems and its potential has
been emphasized. However, the behaviour andmechanisms of electrocaloric effect in the PMN-PT
system are still unclear due to a limited amount of
results. Additionally, some discrepancies exist among
both directly and indirectly measured electrocaloricdata.
In the present work the electrocaloric effect is studied
in the (1−x)PMN-xPT (x ≤ 30 %) relaxor ferroelectric
Fig. 127: Electrocaloric effect in PMN-10PT
system in the form of bulk by means of direct as a function of temperature and electric field.
temperature measurements, which enables theobservation of detailed electrocaloric behavior as a function of electric field, temperature andcomposition (see Fig.1 for an example). Specifically, the previous observations of high responsivity
ΔT/E around the critical point385 and development of the “dual-peak” with higher electric fields386,387 areinvestigated in detail.

382

S. Fähler et al., “Caloric effects in ferroic materials: new concepts for cooling”, Adv. Eng. Mater. 14, 10-19, 2012.
A. Mischenko et al., “Giant electrocaloric effect in thin film PbZr0.95Ti0.05O3”, Science 311, 1270-71, 2006.
384
B. Neese et al., “Large electrocaloric effect in ferroelectric polymers near room temperature”, Science 321, 821-823, 2008.
385
B. Rožič et al., “Influence of the critical point on the electrocaloric response of relaxor ferroelectrics”, J. Appl. Phys. 110,064118, 2011.
386
J. Hagberg et al., “Electrocaloric characteristics in reactive sintered 0.87Pb(Mg1/3Nb2/3)O3-0.13PbTiO3”, Appl. Phys. Lett.
92, 132909, 2008.
383

ISAF-P4D-38 ___________________________________________________________________________________________________________________

Design of Wall-plug Efficiency Optimized Semi-active
Piezoelectric Shunt Damping Systems
Jan Václavík1, Pavel Mokrý1, Pavel Márton1
1

Institute of Mechatronics and Computer Engineering, Technical University of Liberec
Studentská 2, Liberec, Czech Republic, CZ-46117
Email: pavel.mokry@tul.cz

Semi-active vibration control devices based on the principle of Piezoelectric Shunt Damping (PSD)
represent a very promising possibility for efficient vibration transmission suppression with minimal
demands on electronics. In the semi-active vibration control device (see Fig. 1), the piezoelectric
actuator is attached to the vibrating structure and connected to an active analog electrical shunt thatbehaves as a negative capacitor. The word ‘active’ means that the electrical shunt consists of a consistsof power supply and an operational amplifier in the electrical network. In this arrangement, it is possible
to highly efficiently control the vibration transmission from the source of vibrations through thepiezoelectric element. It is achieved by actively tuned mechanical impedance of the piezoelectric
actuator. Unfortunately, the efficiency of the electrical part of the device is rather low, since the electric
power transfer in the system has a large reactive component, which is dissipated on the transistors of theoperational amplifier, which is used in the negative capacitor. This yields a situation, where wall-plug
efficiency, i.e. the ratio of mechanical power reflected or absorbed by the actively shunted piezoelectric
actuator over the input electrical power, is extremely low.
The aforementioned issues have motivated the work presented in this Paper. The mechanical and electricenergy flows in two semi-active vibration control systems have been analyzed in detail. The vibration
control systems have been designed and realized to suppress the vibration transmission in narrow andbroad frequency ranges, respectively. The results of our measurements indicate that the average apparent
electrical power in the electric part of the vibration
control device is about 100 times larger than themechanical power, which is supplied to the systemfrom the source of vibrations. Such a situation puts
specific requirements on the design of the negative
Negative
Sourcecapacitor
capacitor electronics.
Electric
energyIn this paper, there will be analyzed strengths andVibration source
weaknesses of the typical realizations of the semiactive vibration control devices and discussed
High efficiency
Low efficiency
principles that can enhance their wall-plug efficiency.
Fig. 128: Semi-active vibration control device,
Optimized concepts that eliminate weaknesses of thewhich consists of a piezoelectric actuator and aaforementioned devices will be presented. The rules negative capacitor.
for designing the highly efficient and low-powerelectronic parts of semiactive vibration control
systems are discussed.

387

L.J. Dunne et al., “Statistical mechanical lattice model of the dual-peak electrocaloric effect in ferroelectric relaxors andthe role of pressure”, J. Phys. D: Appl. Phys. 44, 375404, 2011

ISAF-P4D-39 ___________________________________________________________________________________________________________________

Efficiency measurement in piezoelectric vibration energy
harvesters.
P. M. Weaver1, P. Woolliams1, M.G. Cain1, M. Stewart1
1

National Physical Laboratory, Teddington, UK
Email: paul.weaver@npl.co.uk

Vibrational energy harvesters convert energy from vibrations and movement in the environment into
electrical energy which can be used to power a device such as a wireless sensor node. The energy source
is often considered as “waste” energy and energy harvesting performance is typically characterised bypower output under specified conditions of vibration amplitude and frequency. This takes no account of
the energy extracted from or available from the source. This is important where account needs to betaken of the loading of the source by the harvester. This includes “parasitic” harvesting where the energy
derived from the source is not “free” or wasted, and use of the energy harvester increases the power
consumed by the source. Examples include human or vehicle powered applications where it is theavailability of the energy source rather than energy saving that is the main motivation. It is also
important in situations where the power from the source is limited. In these cases, the ratio of power out
to power in, or the efficiency needs to be known.
Measuring efficiency is more complex than measuring power out under well-defined vibration
conditions, because of the requirement to measure the power transferred from the source to the energy
harvester. Often the harvested power is a small fraction of the total power delivered by the system. We
are not aware of any published reports of measurement of efficiency, although it is discussed in somemathematical models of energy harvesters.
In this paper we describe an experimental method of measuring efficiency for resonant piezoelectric
cantilever energy harvesters based on a damped oscillator response to an impulse input. Experimental
results for typical energy harvesting devices are presented.

This work has been performed in the framework of the joint research project “Metrology for Energy
Harvesting”, which is supported by the European Metrology Research Programme (EMRP), jointly
funded by the EMRP participating countries within EURAMET and the European Union.

ISAF-P4D-40 ___________________________________________________________________________________________________________________

SiO2/SiN Infrared Absorbing Films for Uncooled Pyroelectric
Sensor and its Fabrication and Evaluation
Koji Oishi1, Daisuke Akai2, Makoto Ishida1, 2
1Electric and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi,
Aichi, Japan
2
Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University ofTechnology, Toyohashi, Aichi, Japan
Email: oishi-k@int.ee.tut.ac.jp

Uncooled Infrared sensor is widely used for human detection. The pyroelectric sensor has
advantage of high sensitivity and is possible to integrate on Si substrate with MEMS technology, and it
possesses possibility for improvement in many ways. Our approach to improving sensor is to control
crystalline orientation of Pb(Zr, Ti)O3 (PZT) film using epitaxial -Al2O3 grown on Si substrate. Other
sensor consisting material such as electrode is also grown with crystalline orientation controlled388.
Absorption of infrared that convert to heat is also the key factor for the improving sensitivity. We
proposed new absorbing film using SiO2 and SiN for our PZT thin film pyroelectric infrared sensor. We
have researched the fabrication and evaluation of the absorbing film and the sensor.
Our sensor structure is PZT capacitor
consists of SrRuO3(SRO)/PZT/SRO/Pt/-Al2O3/Si.
SRO is crystalline electrode that used for buffer
layer for interface of PZT and Pt that adhesion isvery weak, which cause fabrication failure.(Fig.1)
Absorbing film is fabricated by plasma enhanced
chemical vapor deposition, and SiO2(550nm) is
deposited on SiN(850nm). These film possess
specific absorption in wavelength range of 8-14m,often used for human detection. The film is also Fig. 129: Absorbing film on fabricated sensor.
CMOS material and easy to fabricate. The infrared Fabrication is successfully completed withoutabsorption is confirmed both calculation and peeling off or cracks of PZT. PZT thickness:measurement, and they show the similarity in target 450nm
wavelength. Result shows over 70% of averageabsorption is obtained from proposed absorbing
film.(Fig.2)
SiO2/SiN absorbing films is deposited on
sensor structure without fabrication failure. The
responsivity (Rv) of sensor with absorbing film ismeasured with source follower (JFET and 47k
resister) and lock-in amplifier. The Rv of 176 V/W
Fig. 2: Reflectance of SiO2/SiN double layer
is achieved on chopping frequency of 10 Hz.

absorbing film on Pt/Si. The Pt does not transmit
infrared therefore the reflectance shows absorption
characteristics.

388

D. Akai et al., Applied Physics Letter, 86 (2005) 202906

ISAF-P4D-41 ___________________________________________________________________________________________________________________

Effect of Dome-shaped Asymmetric Piezoelectric Multimorph
Ceramic on Frequency Response Characteristics of Piezoelectric
Acoustic Actuator
Hye Jin Kim1 and Woo Seok Yang1
1

Nano Convergence Sensor Research Section, IT Materials and Components Lab., Electronics andTelecommunications Research Institute (ETRI), Daejeon, South Korea
Email: nolawara@etri.re.kr

Recently, the piezoelectric acoustic actuators have attracted a great deal of attention owing to theirseveral benefits of being thinner, more power-efficient and lighter than the traditional dynamic speakers.
However, they have still suffered from the bad sound quality due to their fluctuating output soundpressure and high total harmonic distortion characteristics. In this paper, the dome-shaped asymmetricpiezoelectric multimorph ceramics are proposed to achieve good sound quality of the piezoelectric
acoustic actuators which means flat and smooth frequency response characteristics on a wide playing
frequency range. In order to investigate the effect of asymmetric piezoelectric multimorph ceramic on
the frequency response characteristics of the piezoelectric acoustic actuator, we simulated and analyzed
the vibrational and output acoustic spectrums using the finite-element analysis (FEA) and the laser
scanning vibrometer (LSV) and B&K pulse analyzer equipment.
The fabricated piezoelectric acoustic actuator was comprised of a PZT ceramic membrane and an
acoustic diaphragm. Herein, PZT piezoelectric ceramic sheet was prepared to have an asymmetric triplelayered multimorph structure, which is composed ofthree piezoelectric layers: upper and lower
piezoelectric active layers and a dummy layer. The
upper and lower piezoelectric active layers consistedof 2 and 4 individual piezoelectric element layers,respectively.
As shown in Fig. 1, it is observed that the measured
output sound pressure of the fabricated piezoelectric
acoustic actuator was quite improved to be flat andsmooth spectrum by the dome-shaped asymmetricpiezoelectric ceramic. Especially, the significant dip at
3.35 kHz was dramatically enhanced by about 15 dB. Fig. 130: The output sound pressure levels of thefabricated piezoelectric acoustic actuator with theThis result is due to the dome-shaped structure of thedome-shaped asymmetric multimorph ceramic,
asymmetric triple-layered multimorph, which is compared to the flat symmetric triple-layered
obtained by the polarization process. From the ceramic and commercial piezoelectric speakers.
polarization process, the proposed asymmetricpiezoelectric ceramic was bended to the arched profile due to the difference of the lateral shrinkages
between upper and lower active layers, which can possesses both large displacement and loading ability
performance. This paper presents that the dome-shaped asymmetric piezoelectric triple-layered
multimorph ceramic can not only improve the sound quality of the piezoelectric acoustic actuator by aflat and smooth frequency response characteristics but also allow high sound pressure characteristics
comparable to the commercial piezoelectric acoustic actuator.

ISAF-P4D-42 ___________________________________________________________________________________________________________________

AlN cantilever for differential pressure sensor
Yutaka Tomimatsu1,2, Hidetoshi Takahashi3, Takeshi Kobayashi1,4, Kiyoshi Matsumoto3,
Isao Shimoyama3, Toshihiro Itoh1,4 and Ryutaro Maeda1,4
1

NMEMS Technology Research Organization, JAPAN2
Seiko Instruments Inc., JAPAN3
The University of Tokyo, JAPAN
4
National Institute of Advanced Industrial Science and Technology (AIST), JAPAN
Email: ytomimatsu@nmems.or.jp
MEMS cantilever type force sensors
have been widely developed for many
applications389390. Among them, acantilever type differential pressure
sensor has a higher sensitivity than
traditional diaphragm type sensors
because only the base part of thecantilever is fixed. Previous sensor uses
a piezoresistor for the sensing element.
Thus, the sensor needs power Fig. 131: (a) Concept of the differential pressure sensor using a
consumption of several milliwatts to AlN cantilever. (b) Photograph of the fabricated sensor chip.
apply the bias voltage.
We propose a piezoelectric cantilever type differential pressure sensor as shown in Fig. 1(a). A piezoelectric
type sensor does not require power consumption to drive the sensing element. Thus, a differential pressure
sensor with high sensitivity and low power consumption is achieved.
In this research, Aluminum nitride (AlN) was used as the piezoelectric material due to its chemical stability
and small dielectric constant391. We designed and fabricated the AlN cantilever, and the force sensitivity of
the fabricated sensor was evaluated.
Fig.1(b) shows a photograph of the fabricated cantilever. The cantilever was fabricated from the multilayerof Pt/Ti/AlN/Pt/Ti/SiO2 deposited on a silicon on insulator (SOI) wafer. The cantilever, which is formed on
the center of the sensor chip, is 1500 μm × 1000 μm × 2 μm in size. The AlN layer is formed on the base of
the cantilever where strain is concentrated. The spring constant is designed to be 0.27 N/m. The capacitanceof the fabricated cantilever is 70 pF.
The displacement sensitivity of the fabricated cantilever was measured by moving a PZT actuator thattouched the center of the cantilever. The piezoelectric voltage was generated according to the displacementof the actuator. Based on this measurement, the displacement sensitivity was calculated to be 3.3 mV/μm.
From the result and the calculated spring constant, the force sensitivity was obtained to be 12 mV/μN.

389

M. Tortonese et al., "Atomic resolution with an atomic force microscope using piezoresistive detection," Applied Physics
Letters, vol. 62, pp. 834-836, 1993.
390

H. Takahashi et al., "Differential pressure sensor using a piezoresistive cantilever," Journal of Micromechanics andMicroengineering, vol. 22, pp. 055015, 2012.
391

V. Cimalla, et al., "Group III nitride and SiC based MEMS and NEMS: materials properties, technology and applications,"
Journal of Physics D: Applied Physics, vol. 40, no. 20, pp. 6386–6434, 2007.

ISAF-P4D-43 ___________________________________________________________________________________________________________________

Application driven design, fabrication and characterization ofpiezoelectric energy scavenger for cardiac pacemakers
Mikael Colin, Libor Rufer, Skandar Basrour
TIMA (CNRS, G-INP, UJF), Grenoble, FRANCE
Email: Libor.Rufer@imag.fr
The disruptive innovation in pacemakers and implantable cardioverter defibrillators (ICDs) will provide
implants that do not require electrical leads. Main actors in the field of cardiac rhythm management(CRM) implants prepare miniaturized and autonomous leadless implants, which could be directly placed
inside a human heart. Several concepts for powering stand-alone cardiac implants were proposed392 in
the past, and recently the first study of an energy scavenging system placed in the human heart has beenpresented393. The study was conducted for a relatively large system operating at 40 Hz. We will
demonstrate, that according to the heart beat acceleration spectrum obtained by placing accelerometersinside several heart cavities394, the useful vibration energy is rather localized at lower frequencies (15 to
30 Hz). We will also detail the dimensional restrictions in the case of a leadless pacemaker. Since it has
to be placed into a heart through veins, the device is expected to be of cylindrical shape with a diameterof about 6 mm.
We will present the design, simulation, fabrication and characterization of piezoelectric vibration energy
scavenger for cardiac implants. We will discuss the energy content of the heart vibration spectrum in aview of energy harvesting. We will place emphasis on the nature of the spectrum, the energy frequencies
and corresponding amplitudes. We will present an application driven design of a resonant piezoelectricenergy scavenger aiming at powering a leadless pacemaker with a useable energy of few µJ perheartbeat. Such an energy scavenger consists of a piezoelectric bimorph cantilever with 20 µm thickPb(ZrxTi1-x)O3 layers. A simulation study in both ANSYS® and Simulink® environments, has shownthat the proposed design delivers the required energy.
However, none of the current fabrication processes can be used for manufacturing such PZT thick films.
Using processes derived from the microelectronic field such as Sol Gel deposition or sputtering, themaximum achievable thickness is about 2 to 5 µm. In contrary, using co-firing techniques, the PZTplates can hardly be thinner than 100 µm. As aconsequence, the manufacturing of the above-describedpiezoelectric scavenger corresponds to an actual process
blind
window. In this paper, we present the fabrication of anultra
low-frequency device (15 Hz) using optimized grindingandpolishing techniques. The obtained experimental results areingood agreement with our analytical and numericalmodeling (Figure 1).

392

Fig.1: Experiment/simulation results
W. H. Ko, “Piezoelectric energy converter for electronic implants”, US patent 3,456,134, 1969.

393

M. A. Karami, D. J. Inman, “Powering Pacemakers from heartbeat vibration using linear and non linear energy harvester”,
Applied Physics Letters, vol. 100, 042901, 2012.
394

M. Deterre, B. Bouteaud, R. DalMolin, S. Boisseau, J-J. Chaillout, E. Lefeuvre, E. Dufour-Gergam, “Energy harvesting
system for cardiac implant applications”, Symposium on the Design, Test, Integration and Packaging of MEMS/MOEMS(DTIP), May 11-13, 2011, pp. 387-391.

ISAF-P4D-44 ___________________________________________________________________________________________________________________

Impact of domain depth on SAW generation by acoustic
superlattice transducers in 128˚ YX-cut lithium niobate
Didit Yudistira1, Andreas Boes1,2, Amgad Rezk1, Tristan Crasto1,2, Hendrik Steigerwald1,2, Elisabeth
Soergel3, James Friend1, Arnan Mitchell1,21Electrical and Computer Engineering, RMIT University, VIC 3001, Melbourne, Australia
2
Center for Ultra-high Bandwidth Devices for Optical Systems (CUDOS)
3
Institute of Physics, University of Bonn, Wegelerstr. 8, 53115 Bonn, Germany
Email: didit.yudistira@rmit.edu.au

Acoustic superlattice (ASL) transducers comprising periodic domain inversion on Z-cut lithium niobate (LN)
achieved with electric field poling, and coplanar electrode have been demonstrated as an alternative means ofsurface acoustic wave (SAW) generation beside more common interdigitated transducer395. While its
applications in the integrated optics have been reported396, in many other SAW applications such as in
Microfluidics, 128 YX LN is preferable because it has the largest coupling constant (5.3%) compared to Zcut (0.53%). However, to achieve domain inversion on this cut using electric field poling is relatively
difficult because of its inclined polarization axis. In our distinct submission to this conference, for the firsttime periodic domain inversion on 128 YX LN has been achieved by means of UV direct writing. However,these engineered domains canbe quite shallow. Here, we
analyse SAW generation on
128 YX cut LN studying inparticular the impact of
domain depth.
The studied structure ispresented in the inset of Fig.
1(a) with domains of constantperiod  and variable depth .
Fig. 132: (a) Out-going surface bound acoustic energy (T) vs normalized
We define the normalized
domain depth (), displacement profiles with: (b) , and (c) parameter
The
structure, was simulated using the finite element method assuming a stress free boundary condition (BC) on
the surface except at the periodic domain surface where Dirichlet BC, VRF=1 V, is imposed. The remaining
boundaries are terminated with Perfectly-matched layers. Figure 1(a) shows the fraction of the total acoustic
energy leaving the transducer that passes through region A and indicates that a bound SAW is achieved when≈0.3 as clearly shown in Fig. 1(b). If the depth is further increased beyond the lattice period thegenerated SAW is more localized within the periodic domain, as shown in Fig. 1(c).
These predictions show that efficient propagating SAW generation on shallow-depth 128 YX acoustic
superlattice should be possible, provided the domain depth is 30% of the lattice period. Such an aspect ratio
is quite achievable with the UV domain writing approach.

395
396

D. Yudistira, S. Benchabane, D. Janner, and V. Pruneri, Applied Physics Letters, 95, 052901 (2009).
D. Yudistira, D. Janner, S. Benchabane, and V. Pruneri, Optics Express, 18, 21781 (2010).

ISAF-P4D-45 ___________________________________________________________________________________________________________________

Improved Microwave Dielectric Properties of Nd(Mg0.5Sn0.5)O3
Ceramics with Ba Substitution
Yih-Chien Chen and Min-Zhe Weng
Department of Electrical Engineering, Lunghwa University of Science and Technology, Gueishan
Shiang, Taoyuan County, Taiwan
Email: ycchenncku@yahoo.com.tw
Many investigations of Nd(Mg0.5Sn0.5)O3 ceramics have investigated their potential application inmodern communication systems. A dielectric constant of 19.3 and a Q  f of 43,300 GHz were obtainedfor Nd(Mg0.5Sn0.5)O3 ceramics that were sintered at 1550 OC for 4 h397. Since the ionic radius of Ca2+
(0.100 nm) exceeds that of Mg2+ (0.072 nm), La(Mg0.5-xCaxSn0.5)O3 ceramics have better microwave
dielectric properties than La(Mg0.5Sn0.5)O3 ceramics398. This fact motivated this study of the effect of thesubstitution of Mg2+ ions (0.072 nm) by Ba2+ ions (0.135 nm) to form Nd(Mg0.5-xBaxSn0.5)O3 (NMBS)
ceramics. The effect of the sintering temperature on the microwave dielectric properties of NMBS
ceramics was investigated. The microwave dielectric properties of NMBS ceramics were found to varywith the extent of Ba2+ substitution and sintering temperature. The microwave dielectric properties were
further analyzed by densification, X-ray diffraction patterns, and observation of their microstructures.
The X-ray diffraction patterns of the Nd(Mg0.47Ba0.03Sn0.5)O3 ceramics revealed no significant
variation of phase with sintering temperatures. Nd(Mg0.47Ba0.03Sn0.5)O3 ceramics that were sinteredat 1600 OC for 4 h had an apparent density of 6.91 g/cm3, a dielectric constant of 19.14, a Q  f of
97,500 GHz, and a f of -65.4 ppm/OC. The density and formation of Nd2Sn2O7 affected thedielectric constant and Q  f of NMBS ceramics. The dielectric constant of NMBS ceramics was also
depended on the ionic polarization.

21

6.4

18

6.1

5.8
1450

15
x=0.01x=0.03x=0.05x=0.01x=0.031500
1550 x=0.05
1600
1650
Sintering Temperature (OC)

Quality Factor (GHz)6.7

100000-20
x=0.01x=0.03x=0.05x=0.01x=0.03x=0.05

80000
60000

398

-40

40000

-50

20000

-60

0
12
1700

1450

-70
1500

1550 1600

1650
O

Sintering Temperature ( C)

Fig. 1. Microwave dielectric properties of Nd(Mg0.5-xBaxSn0.5)O3 ceramics.

397

-30

Y.C. Chen, R.J. Tsai, Mater. Chem. Phy. vol. 129, p.116-120, 2011.
Y.C. Chen, M.D. Chen, J. Phys. Chem. Solids vol. 72 p. 1447-1451, 2011.

1700

Temperature Coefficient ofResonant Frequency (ppm/OC)

24

Dielectric Constant3

Apparent Density (g/cm)

7

ISAF-P4D-46 ___________________________________________________________________________________________________________________

Analysis of guided wave propagation in(1−x)Pb(In1/2Nb1/2)(Mg2/3Nb1/3)O3–xPbTiO3 piezoelectric media
H. Wang1, T. Baron1, W. Daniau1, B. Dulmet1 S. Ballandras2
1

FEMTO-ST Institute, UMR 6174, Université Franche-Comté, CNRS, ENSMM, UTBM, 32 avenue del’observatoire, 25000 Besançon cedex, France
2
Frec|n|sys SAS, 18 rue Alain Savary, 25000 Besançon cedex, France
Email: haixia.wang@femto-st.fr

Currently the different piezoelectric materials with superior high electromechanical coupling coefﬁcient
have been found such as (1−x)Pb(Mg1/3Nb1/3)O3–xPbTiO3 (PMNT) crystal 399. It was also discoveredthat the coupling factor of shear mode can be larger if these crystals are polarized properly400, comparedwith the commonly used piezoceramics and crystals. It means that these crystals may trigger a
revolution in the performance of next generation electromechanical devices. Therefore, a thoroughtheoretical investigation on the guided wave propagation in these piezoelectrics is very useful both for a
fundamental understanding on wave phenomena and for potential applications.
Our theoretical studies focus on the validation of guided wave with pure horizontal shear mode inpiezoelectric orthorhombic media with mm2 symmetry, and how k2 of these modes change when auniform metal layer is deposited in the surface. The investigation elucidated the necessary condition for
the existence of pure shear Bleustein-Gulyaev wave in mm2 even with large coupling factor and also
general condition V<Vth required for all materials. The velocity function and dispersion relation havebeen deduced in materials with mm2 and also 4mm symmetry. With the measured parameters in the
PIMNT crystal we found that the existence of Bleustein-Gulyaev wave in both symmetries is validated
and this wave is totally decoupled from Rayleigh wave. The maximum coupling factor k2 about 50% ataround 37oYX with velocity Vm=1696m/s and Vf= 2273m/s can be obtained in crystal with mm2
symmetry. The corresponding measurements and applications will be further investigated under the
optimum choice of layered structure with metal and insulator film deposited on the top of substrate
without badly sacrificing k2 for the response, since one can expect that devices based on these guided
waves may be useful in the near future.

399

Service R F 1997 Science 275 1878

400

Zhang R, Jiang B, Jiang W H and Cao W W 2006 Appl. Phys. Lett. 89 242908

ISAF-P4D-47 ___________________________________________________________________________________________________________________

Measurement of Radiant Energy using Pyroelectric
Polymer/Ceramic Composite
Edinilton Morais Cavalcante1, Darcy Hiroe Fujii Kanda1, Washington Luiz de Barros Melo2, Gilberto deCampos Fuzari Jr.3, Walter Katsumi Sakamoto1
1

Departamento de Física e Química, Universidade Estadual Paulista – UNESP, Ilha Solteira, São Paulo,
Brazil.
2
Empresa Brasileira de Pesquisa Agropecuária – EMBRAPA, São Carlos, São Paulo, Brazil.
3
Instituto de Ciências Exatas e da Terra, Universidade Federal de Mato Grosso – UFMT, Barra doGarças, Mato Grosso, Brazil.
Email: sakamoto@dfq.feis.unesp.br

Monitoring non-ionizing radiant energy is increasingly demanded for many applications such as
automobile, biomedical and security system. Thermal type infrared (IR) sensors can operate at room
temperature and pyroelectric materials have high sensitivity and accuracy for that application. Working
as thermal transducer pyroelectric sensor converts the non-quantified thermal flux into the output
measurable quantity of electrical charge, voltage or current. In the present study the composite made ofpoly(vinylidene fluoride) – PVDF and lead zirconate titanate (PZT) partially recovered with polyaniline(PAni) conductor polymer has been used as sensor element. The pyroelectric coefficient p(T) was
obtained by measuring the pyroelectric reversible current, i.e., measuring the thermallystimulated depolarization current (TSDC) after removing all irreversible contribution to thecurrent such as injected charge during polarization of the sample. The scheme in Figure 1 showsthe experimental setup to analyze the sensing property of the pyroelectric material. In that
scheme, the sensor is irradiated by a high power light source (halogen lamp of 250 W) that is
chopped providing a modulated radiation. A device assembled in the laboratory is used to change
the light intensity sensor, an aluminum strip having openings with diameters ranging from 1 to 10
mm incremented by one millimeter. The sensor element is assembled between two electrodes while
its frontal surface is painted black ink to maximize the light absorption. The signal from thesensor is measured by a Lock-In amplifier model SR530 – Stanford Research Systems. Figure 2
shows the behavior of the output voltage for an input power at several frequencies for PZT-PAni/PVDF(30/70 vol%) composite. The signal amplitude follows the inverse power law (1/f) and the linearity canbe observed in the frequency range used.

output voltage (mV)PZT-PAni/PVDF 30/70 5MV/m, 15min

10

1

10

0

5x10

1

10

2

1,5x1022x102Frequency (Hz)Fig. 1 - Block diagram of thephotopyroelectric detection.

Fig. 2 – photopyroelectric response as
a function of frequency.

ISAF-P4D-48 ___________________________________________________________________________________________________________________

Tunability and Sensitivity Modification by Poling on PZT Film ofFrequency-Tunable Ultrasonic Microsensors
Kaoru Yamashita, Hikaru Tanaka, Atsushi Morimoto, Yang Yi, Minoru Noda
Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto, Japan
Email: yamashita.kaoru@kit.ac.jp
Frequency-tunable piezoelectric ultrasonic microsensors have been fabricated and tested in terms oftunability and sensitivity changes induced by poling. Figure 1 shows a schematic illustration of thesensor structure. Sol-gel derived lead-zirconate-titanate (PZT) thin film capacitors are formed on silicondioxide diaphragms. The top electrode of the capacitor is divided into the inner part for sensing and theouter part for resonant frequency tuning401. The tunable sensors are utilized to multiple-frequency
technique for high resolution and ghost suppressive ultrasonic measurement on a sparse phased array402.
The resonant frequency draws a butterfly curve1, as shown in Fig. 2 (a), reflecting ferroelectric
polarization hysteresis to the applied tuning voltage, similar to the cases of piezoelectric diaphragm
actuators403.
Although the poling onto the sol-gel PZT film is known to improve the piezoelectric property404, theinterference between the poling and the tuning on the tunable sensors was not clear. In this work, thesensor performance has been characterized upon poling voltage application on the sensing electrode.
The results are shown in Fig. 2, where the poling state is initial (before poling), poled at 8 V anddecreased poling voltage to 0 V as illustrated in the insets. The butterfly curve shifts to slightly higher
frequency by the 8 V-poling due to additional converse piezoelectric stress and maintains the shift after
the poling voltage is decreased to 0 V, as shown in Fig. 2 (a). The frequency shift slightly decreases thetunability but it is still enough for the dual-frequency measurement technique. Figure 2 (b) shows
improvement of sensitivity by the poling at 8 V and also it is maintained after the poling voltage isdecreased to 0 V. Although a tensile stress to the poled sol-gel PZT was reported to increase its
piezoelectric coefficient e31,f405, the sensitivity of the poled sensor raises much higher than that by thee31,f increase at a higher tuning voltage range, while that of the unpoled sensor shows a low sensitivity
with the reversed response to the tuning voltage due to less aligned polarizations toward possibly thereversed direction. As the result, we can utilize the tunability up to 200% by selecting tuning voltages as
1 V and 6 V for a dual-frequency technique, avoiding polarization reversal, and the improved sensitivity
by five times through poling on the sensing electrode at 0 V through 8 V.

Fig. 1: A schematic illustration of the sensor
structure and electrode configuration.
1

Fig. 2: Sensor performance at the initial, after poled at 8 V and thendecreased poling voltage to 0 V; (a) for the tunability and (b) for thesensitivity.

K. Yamashita, K. Tomiyama, K. Yoshikawa, M. Noda, M. Okuyama, Ferroelectrics, vol. 408, p. 48–54, 2010.
K. Yamashita, K. Tomiyama, K. Yoshikawa, M. Noda, Procedia Chem., vol. 1, p. 540–543, 2009.
P. Muralt, A. Kholkin, M. Kohli, T. Maeder, Sens. Actuat. A, vol. 53, p. 398–404, 1996.
404
K. Yamashita, M. Okuyama, IEEJ Trans. SM, vol. 124, p. 124–128, 2004.
405
M. A. Dubois, P. Muralt, Sens. Actuat. A, vol. 77, p. 106–112, 1999.
402
403

ISAF-P4D-49 ___________________________________________________________________________________________________________________

Switchable bandpass filters using acoustically coupled ferroelectric FBARs
Andrei Vorobiev and Spartak Gevorgian
Department of Microtechnology and Nanoscience, Chalmers University of Technology,
Gothenburg, Sweden
andrei.vorobiev@chalmers.se; spartak.gevorgian@chalmers.se
In multiband-multichannel microwave communications systems filters are one of the most criticalcomponents affecting the cost, performance and form factor of the handsets and systems. Tunable andswitchable filters are considered as a possible solution to the problem. Intrinsically switchable andtunable Film Bulk Acoustic Wave resonators (FBAR) based on ferroelectrics (utilize electric field
induced piezoelectric effect) appear to be one of the most promising technologies for these applications.
Recently attempts are made to improve the performance of these filters in terms of low losses and highout-of-band rejection406,407. While for the lower insertion losses FBARs with high Q-factors are
required, the out-of-band rejection and steepness of the skirts in ladder filters may be improved by using
inductors in series with the shunt resonators2 and by using acoustic coupling between the series
resonators1. The filter using acoustically coupled resonators having rectangular or polygon form often
suffer from spurious resoances1.
In this work voltage switchable bandpass filters based on acoustically coupled FBARs are considered.
To avoid generation of the spurious resonances FBARs having semicircular electrodes are used, Fig.1a.
The filter makes use of BiFeO3-BaTiO3 films. A 100 nm thick Pt film is used as the bottom electrodes.
The top electrode is made of 100 nm Al. Details of fabrication and measurements are reported in anarticle408. .
8V

a)

0V

b)

Fig.1 Microphotograph (a) and measured off (Vbias=0) and on (Vbias=8V) state S21. Diameter ofelectrodes is 60 m, slotwidth is 1.0 m.
Filters with different sizes and slotwidth between the semicircular electrodes are fabricated andmeasured. The Q-factor of the resonators is estimated to be about 80 at resonant frequency of 3,695 GHz
under DC bias voltage 8V applied to each of the resonators. As is seen in Fig.1b the filter is free of
spurious resonances with a clear 3dB pass band of 3%. The return losses are -13dB. However, thecoupling is still week and the losses in input/output strips are high which result in higher dumping in the
passband. The future plans include optimization of the designs/coupling strength.
This work is supported by Swedish Science Council Vetenskaprådetv via project VR-FBAR.
406

S. Sis, V. Lee and A. Mortazawi, “Intrinsically Switchable, BST-on-Silicon Composite FBARs”, IEEE IMS’2011, pp.1-4

407

S. Gevorgian, A. Tagantsev and A. Vorobiev, Tuneable Film Bulk Acoustic Wave Resonators, Springer 2013

408

A.Vorobiev etc. “Intrinsically tunable 0.67BiFeO3-0.33BaTiO3 thin film bulk acoustic wave resonators”, Appl. Phys.
Lett., vol. 101, p. 232903-5, 2012

ISAF-P4D-50 ___________________________________________________________________________________________________________________

Piezoelectric energy harvesting device using PZT nanorods withsingle crystal structure
Seok-Jin Yoon, Woo-Suk Jung, Chong-Yun Kang
Electronic Materials Research Center, Korea Institute of Science and Technology (KIST),
Hwarangno 14-gil 5, Seongbuk-gu, Seoul, Korea
Email: jws7216@gmail.com

Piezoelectric nanocomposite generator (NCG) is realized with PZT nanorods and Polydimethylsiloxane(PDMS) polymer. The PZT nanorods were fabricated by hydrothermal method, resulting in a single
crystal structure and the epitaxial growth of the nanorods. The PDMS was utilized for the flexibility of
the nanogenerator and mixture of Ag nanowires with PZT-PDMS composite for the enhancement of
power generation. A power generation principle of the PZT-PDMS NCG and the role of the Ag
nanowires were verified from the comparison of output performances from the generators. The NCC
generator produces a peak voltage of ~2.5 V and current of 200 nA. The piezoelectric nanocomposite
technique reported here successfully overcomes the size-related restrictions and enables simple, lowcost, and large-scale stabled generator. These results represent a critical step in the realization of selfpowering nanotechnology that harvests electricity such as wireless sensors, implantable devices,personal electronics, MEMS, and so on.

Fig. 133: Fabricated PZT-PDMS nanocomposite generator and its output performance.

ISAF-P4D-51 ___________________________________________________________________________________________________________________

Remanent polarization and electromechanical properties of LTCCPZT monomorphs
Sobocinski Maciej, Juuti Jari, Jantunen Heli
Microelectronics and Materials Physics Laboratories, University of Oulu, Finland
Email: maciej.sobocinski@ee.oulu.fi

Poling is a crucial stage in polycrystalline ceramic in order to exhibit piezoelectric properties. In the caseof Low Temperature Co-fired Ceramic embedded piezoelectric bulk structures, poling is necessary stepof manufacturing as elevated temperature of the process is far above the Curie temperature of common
PZT compositions. In previous works by the authors409410411, LTCC embedded structures were poledwith 1.6 kV/mm and higher fields were restricted by occurring electrical breakdown during the poling.
Although sufficient remanent polarization has been obtained, further improvement of poling should beemphasized. This paper focuses on optimization of the poling conditions for LTCC-PZT unimorph
structures. The problem of occurring electrical breakdown has been solved by applying additional
dielectric layer at the edges of the structure. Hysteresis measurements were done from 0.1 V/µm to 3
V/µm for three temperatures: 25 °C, 75 °C and 125 °C. Remanent polarization of 22 µC/cm2 was
obtained for the monomorph structure with 3.7 V/µm poling field at 125 °C. Subsequently LTCC-PZT
samples were poled in the optimal conditions and electrical and electro-mechanical properties wasmeasured and compared to previous results. Higher remanent polarization and planar coupling effectwas obtained.












ISAF-P4D-52 ___________________________________________________________________________________________________________________

Stress-modified phase transitions in polarized PMN-PIN-PT, KN
and KNL-NTS single crystals/textured ceramics: thermal
expansion and Raman scattering studies
Aneta Slodczyk1, Gwénael Gouadec1, Philippe Colomban1, Mai Pham Thi2
1

2

LADIR, umr7075 CNRS - UPMC, Paris, France
THALES Research & Technology-France, 91767 Palaiseau, France
Email: philippe.colomban@upmc.fr

Due to their high application potential various piezoelectric single crystals are widely investigated.
Since, their outstanding properties result from very complex physical and chemical behavior usuallylimited to the local structure/nanostructure, specific methods of analysis are necessary. Consequently,
we have performed the thermal expansion and Raman scattering studies of lead based PMN-PIN-PT
relaxorferroelectric
singlecrystalsandalead-freeKN
or
KNL-NTS(K0,38Na0,52Li0,04)(Nb0,86Ta0,10Sb0,04)O2,97 ferroelectric solid solution single crystal/textured ceramic. The
used techniques probe well the local nano-heterogeneity and allow detecting the structural phasetransitions as a function of temperature and applied stress. Since, the polarization plays a key role in the
behavior of complex, multi-domains (relaxor) ferroelectrics, the single crystals were preliminary poledalong the [001] and [101] crystallographic directions. A sequence of two 1st order structural phasetransitions is clearly seen in the case of KNN solid solution whereas more complex structuralmodifications: contraction/expansion (as a function crystallographic direction) are also detected at 70°C
(KN) and 121°C (PMN-PIN-PT), respectively. The dependence of phase transition character/force andtemperatures on applied stress/pressure is discussed. The phase transitions determined by dilatometry
are in good agreement with the results of Raman scattering recorded as a function oftemperature/pressure in a wide (Stokes and anti-Stokes) wavenumber range. For example, such analysis
revealed the presence of strong soft mode behavior in the case of KN single crystal.
PMN-PIN-PT

2 MPa 425°C
15 MPa

KN

L/L0

L/L0

0,000

-0,005150°C

15 MPa
5 MPa

0,003

0,005
220°C

Fig. 1. Thermal
expansion curves ofpolarized KN and
PMN-PIN-PT
single crystals
measured parallelto [001] undervarious stress (2/5
and 15MPa).

0,004

405°C

178°C

0,010

0,002
0,001

70°C
-0,010

121°C

0,000
100

200

300

400

Temperature / °C

500

50

100

150

200

Temperature / °C

Raman spectra recorded while rotating the sample around the microscope optical axis allowed
determining the Raman modes sensitive to the symmetry/polarization changes. Raman mapping wererecorded with (VV and VH) and without selection of the scattered light polarization before and after
various temperature/pressure cycles for samples in polarized and depolarized states.

ISAF-P4D-53 ___________________________________________________________________________________________________________________

Investigation of poling behavior under complex loading
conditions
Sophia Eßlinger1, Rostislav Svidler1, Peter Neumeister1, Andreas Schönecker1
1

Fraunhofer-IKTS, Dresden, Germany

Email: Sophia.Esslinger@ikts.fraunhofer.dePiezoceramic transducers are key components in smart structures, providing the desired active functions.
The integration of the active material during manufacturing often has thermal or mechanical impact on
the piezoelectric material, altering its properties. Thus, knowledge of the effects of these influences on
the piezoelectric ceramic is essential to optimize manufacturing and to predict material behavior.
The polarization of ceramics is a key step in activating the piezoelectric coupling. Former measurementsof switchable polarization of soft piezoelectric ceramics disclosed a characteristic dependency of theremanent polarization Pr on the applied electric field strength E and the temperature T1. The correlations
between remanent polarization and performance data for unclamped transducers are empirically known.
Polarization measurements under compressive2 and tensile loadings3 are reported for piezoelectric
ceramics, whereas measurements on compressive
loading orthogonal to the electric field and polarization
are only rarely reported in the literature4. The
considered manufacturing technologies of our research
imply orthogonal compressive load, motivating us tosampleextent measurements of polarization and related
functional data in this condition. For being able to dosystematic studies on various samples, a test set-up
allowing for orthogonal uniaxial, orthogonal biaxial andorthogonal isotropic loading is currently developed, see
Fig.1.
1

M. Nicolai, S. Uhlig, A. Schönecker, A. Michaelis, “Experimental
Investigation of Non-linear Behavior of PZT Piezoceramics at
Low Temperatures”, Advances in Science and Technology Vol. 56 Fig. 1: Exploded view of the sample
holder (cross section) allowing for(2008) pp 105-110.
2Zhou, D.: Experimental Investigation of Non-linear Constitutive
orthogonal isotropic loading
Behavior of PZT Piezoceramics. Dissertation. Universität
Karlsruhe, Karlsruhe, 2003.
3
Guillon, O.; Thiebaud, F.; Delobelle, P.; Perreux, D.: Tensile behavior of PZT in short and open-circuit conditions. In
Materials Letters 58 (6), 2004, pp. 986–990.
4
Kounga Njiwa, A. B.; Aulbach,E.; Granzow, T.; Rödel, J.: Influence of radial stress on the poling behaviour of leadzirconate titanate ceramics, Acta Materialia 55 (2007) 675–680.

ISAF-P4D-54 ___________________________________________________________________________________________________________________

Stability study of [011] ternary PIN-PMN-PT relaxor ferroelectric
single crystals under high electric field and compressive stress
Th.Pastureaud1, M. Dosiy1, F-X Launay1, R. Thannberger1, P. Finkel2, H. Robinson2, J. State2,
C.Murphy2, E. Leveugle3 and M. Pham-Ti3
1
Thales Underwater System, Acoustic & Mechanical Competence Centre, 525 route des dolines, BP
157, 06903 Sophia-Antipolis cedex, France
2
Naval Undersea Warfare Center - Devices, Sensors & Materials R&D, 1176 Howell Street, Newport,
RI 02841
3
Thales Research and Technology, Campus Polytechnique, 1 Avenue Auguste Fresnel, 91767 Palaiseau
Cedex, France
Email: thomas.pastureaud@fr.thalesgroup.com

Piezoelectric properties of [011] poled 32 mode 24PIN-48PMN-28PT single crystals have been studied
under temperature, large stress and electric field. Dielectric drift measurement shows good stability up
to field of 350 Vrms/mm, which appears consistent with polarization field loop measured at room
temperature. Room temperature elastic and piezoelectric responses, measured independently, display
strong and sharp discontinuity at approximately 17 MPa compressive stress that is associated with thestress induced phase transition. These results agree with previous data supporting the conclusion that in
ternaries this instability is likely related to the ferroelectric rhombohedral (R) – orthorhombic (O) phasetransition. In good agreement with existing model, we observe the destabilization of the (R) phase by
applying DC electric field along the poling direction. Stability stress-field-temperature diagrams
defining the linear regions for the crystal are constructed.

ISAF-P4D-55 ___________________________________________________________________________________________________________________PZT materials with compositions at the morphotropic phase boundary (MPB) between the tetragonal(P4mm) and rhombohedral (R3m) phase fields exhibit very high dielectric and piezoelectric properties
which are intensively used for technological applications (sensors and actuators, microelectromechanicalsystems, and high frequency devices) [1]. We recently reported an in situ description of the origin of theferroelectric properties as a function of the applied electric field E based on a synchrotron X-ray
diffraction study [2]. The monoclinic (pseudo-rhombohedral)/ tetragonal phase ratio was found toincrease with electric field which strongly supported the hypothesis of Noheda et al., who explained thestrong piezoelectric properties of PZT by the presence of a monoclinic phase [3] based on a polarization
rotation mechanism [4]. Additionally, polarization flipping of polar lead atoms could unambiguously becharacterized by a maximum in the disorder of lead (Biso(Pb)m) for the positive-negative value of thecoercive field (Ec) in the PS - E hysteresis cycle. Here, we present a structural description of themacroscopic piezo- and ferroelectric properties in the important technological material Lead Zirconate
Titanate (PZT) by in situ synchrotron X-ray and Neutron diffraction. In addition to a technically appliedmaterial, we investigated the poling behavior of different composition series in the vicinity of the MPB.
The structural changes were either induced by variations of the lead oxide content during sintering ordifferent titanium / zirconium ratios. Stroboscopic pump-probe measurements down to 250 μs time
resolution reveal differences in poling kinetics depending on composition. For the technically appliedmaterial they spectacularly comfort our interpretations and clearly show the time structure characterizing
the ferroelectric poling response.
[1] B. Jaffe, W. R. Cook, H. Jaffe, Piezoelectric Ceramics, Academic, London (1971).
[2] M. Hinterstein et al. Phys. Rev. Lett. 107, 077602 (2011).
[3] B. Noheda, D. E. Cox, G. Shirane, J. A. Gonzalo, L. E. Cross, and S.-E. Park, Appl. Phys. Lett. 74,
2059 (1999).
[4] R. Guo, L. E. Cross, S.-E. Park, B. Noheda, D. E. Cox, and G. Shirane, Phys. Rev. Lett. 84, 5423
(2000).

ISAF-P4D-56 ___________________________________________________________________________________________________________________

Study on Electric-field induced Strain and Dielectric Properties of
PMN-PT Ceramics
Wei Zhao1,2, Wei Ruan1, Lizhu Huang1,2, Jiangtao Zeng1, Liaoying Zheng, Huarong Zeng, Guorong Li1
1

Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China
2
University of Chinese Academy of Sciences, Beijing, China
E-mail: zjt@mail.sic.ac.cn

The (1-x)PMN-xPT (0.1≤x≤0.35) ceramics were prepared by columbite method. The correlation of theferroelectric/piezoelectric properties with domain structure was studied systemically. As the PT content
increases, the ferroelectric state of PMN-PT system transforms gradually from the relaxor ferroelectricstate to the normal ferroelectric state, accompanied with the change of electric-field induced strain,
ferroelectric and dielectric properties. Electric-field induced strain reaches the maximum value of 0.25%
at 32 kV/cm for the sample 70/30 due to its piezoelectric character. The P-E loop and dielectric propertyof (1-x)PMN-xPT clarify domain’s contribution to the large strain. The dielectric behavior is found tohave a thermal hysteresis due to the hysteresis of domains state changing between microdomain andmacrodomain.

ISAF-P4D-57 ___________________________________________________________________________________________________________________

Temperature-Dependent Strain Properties of Nb-doped
Bi1/2(Na0.84K0.16)1/2TiO3 –SrTiO3 Lead-Free Piezoelectrics
Rizwan Malik1, Thi Hinh Dinh1, Changhyo Hong1, Hyoung-Su Han1, Wook Jo2, Ali Hussain3 and JaeShin Lee1
1

School of Material Science and Engineering, University of Ulsan, Ulsan, Republic of Korea
2
Institute of Materials Science, Technische Universität Darmstadt, Darmstadt, Germany
3
School of Nano and Advanced Materials Engineering, Changwon National University, Gyeongnam,
Republic of Korea
Email: bestkorean01@hotmail.com
Recently, 0.82(Bi1/2Na1/2)TiO3-0.18(Bi1/2K1/2)TiO3 solid solution (BNKT) ceramics and their modified
ones have attracted great attention because of their large electric field-induced strains (EFIS). However,
BNKT retains a crucial problem of showing high strain values only near room temperature. Meanwhile,actuators for practical applications are required to maintain high strain over a wide temperature range
dependent on their operating environment and self-heating.
In this study, lead-free 0.96[Bi1/2(Na0.84K0.16)1/2TiO3]–0.04SrTiO3 (BNKT-ST) ceramics and Nb-doped
BNKT-ST (BNKNT-ST) were fabricated by the conventional solid-state method, and their dielectric andpiezoelectric properties were investigated as functions of Nb doping level and temperature. The
normalized strain (Smax/Emax) of BNKT-ST was 246 pm/V at room temperature, rapidly increased up to
110oC, and reached its highest value of 742 pm/V. In contrast, the BNKTN-ST showed quite different
Smax/Emax values compared with BNKT-ST. The Smax/Emax was started as 726 pm/V at room temperature.
After that, as rising temperature it decreased gradually and the value was still remaining 560 pm/V at
110oC.

Fig. 134: Comparison of temperature dependence of Smax/Emax between
undoped and Nb-doped BNKT-ST ceramics.

ISAF-P4D-58 ___________________________________________________________________________________________________________________

Comparative study of electrical properties of PbLaZrTiOx
capacitors with Al-doped ZnO and ITO top electrodes
Yoko Takada, Toru Tsuji, Naoki Okamoto, Takeyasu Saito, Kazuo Kondo, Takeshi Yoshimuraa,
Norifumi Fujimuraa, Koji Higuchib, Akira Kitajimab, and Akihiro OshimabaDept. of Chem. Eng., Osaka Prefecture University, Sakai, Osaka, JAPAN
Dept. of Phys. Electro., Osaka Prefecture University, Sakai, Osaka, JAPANb
Inst. of Sci. and Ind. Res., Osaka University, Ibaraki, Osaka, JAPAN
Email: ytakada@chemeng.osakafu-u.ac.jp

Ferroelectric Random Access Memory (FeRAM) has attracted much attention and it is believed to be next
generation non-volatile memory for its high operation (read/write) speed and low power consumption1). For
example, the application of FeRAM includes transportation IC tags, mobile cards, and so on. However,conventional noble metal electrodes for ferroelectric materials, Pt, Ir or IrO2, causes price and resource issues
for FeRAM device fabrication. In this study, we used conductive Al-doped ZnO (AZO)2) and Sn-doped
In2O3 (ITO)3) as an alternative for Pt top electrodes of PbLa(Zr,Ti)O3 (PLZT) capacitors and evaluated theferroelectric properties.
The substrates were highly (111)-oriented sputtered Pt as lower electrodes.
PLZT(Pb:La:Zr:Ti=113:3:30:70) films (500 nm) were prepared by the sol-gel method. The films were depositedon Pt substrate by spin coating, at 3000 rpm for 20 s. Then, the gel-films were dried at 200℃ for 2 min inorder to eliminate the solvent, and pyrolyzed at 300°C for 10 min, in air for organic components removal.
The films were prepared by repeating (3 times) the deposition and pyrolysis cycle. The prepared thickness
was 500 nm. The coated films were finally calcined in air at 750°C, 10 min, in air for achieving
crystallization. Pt top electrodes were deposited by sputtering. AZO and ITO top electrodes were depositedby Pulsed Laser Deposition (PLD). These deposition were performed with a metal through mask having 50
um ~ 500 um diameter. The composition of AZO and ITO targets were ZnO:Al2O3=98.5:1.5 wt.% andIn2O3:SnO2=95.0:5.0 wt.%, respectively.
Initial polarization values of PLZT
capacitors with Pt, AZO and ITO as top
electrodes were 24.1 C/cm2, 20.2 C/cm2
16.2 C/cm2, respectively. Fig. 1 shows thepolarization ratio of PLZT capacitors with Pt,
AZO and ITO electrodes after heating in
200°C, 1 Torr, 3% hydrogen atmosphere.
polarization ratio of PLZT capacitors with Pt
AZO and ITO electrodes after 45 minutes
were 0.23, 0.28, and 0.28, respectively. The
implementation of AZO was promising interms of hydrogen degradation.

and

The

Fig. 1 Changes in polarization ratio of PLZT capacitorswith Pt, AZO and ITO top electrodes at 15 V.

References
1) M.M. Zhang et al., Solid-State Electronics, Vol. 53, p. 473 (2009).
2) A. Suzuki et al., Thin Solid Films, Vol. 517, p. 1478 (2008).
3) A.V. Rao et al., Materials Letters, Vol. 29, p. 255 (1996).

ISAF-P4D-59 ___________________________________________________________________________________________________________________

Leakage Currents in Sol-Gel PZT Films
Alexander Sigov, Yury Podgorny, Konstantin Vorotilov, Alexey Vishnevskiy
Moscow State Technical University of Radioengineering, Electronics and Automation (MIREA),
Moscow, Russia
Email: rector@mirea.ru
Ferroelectrics are used in the capacitor structures of memory devices, therefore leakage currents andelectrical breakdown represent potential problems which should be solved to provide the required
operating characteristics. The study of the current–voltage (I–V) characteristics permits to obtain
information on charge transport mechanisms in PZT films and film-electrode interfaces.
Possible conduction mechanisms in ferroelectric films (dielectrics) are the Schottky and Poole–Frenkel
emissions, the Fowler–Nordheim tunneling, the ohmic, space–charge–limited, hopping conductivity, andconductivity via the grain boundaries412,413.
The objective of this research is to study the conduction mechanisms in PZT ferroelectric thin films
prepared by the sol–gel method on silicon substrates with platinum bottom electrode for different
voltage ramp speed and electric fields strengths. Long–term (tens of minutes) depolarization processes
in metal–ferroelectric–metal (MFM) structure are studied as well.
Main mechanisms of leakage currents in thin PZT ferroelectric films prepared by the sol–gel method are
discussed. Four specific regions are determined in I-V dependences. At very weak fields (10-20 kV/cm)
the current falls with the voltage increase as a result of depolarization. In the low field region (about 70100 kV/cm), the leakage current decreases with decreasing voltage ramp speed, and its components are
the ohmic and displacement currents. In the high field region (≥130 kV/cm) the leakage current
increases with decreasing step voltage ramp, in contrast to the previous case. Possible conductivity
mechanisms are the Pool-Frenkel emission and hopping conduction. In the transition region between
abovementioned ones (from 80–90 to ~130 kV/cm), an abrupt unstable current increase is observed
caused by breakdown of reverse bias Schottky barrier.
Depolarization current is given by a decreasing function which can be approximated by the sum of two
exponents with different relaxation times. As an example, depolarization currents for sol-gel PZT thinfilms prepared at different annealing temperatures are studied. It is shown that both absolute and relativevalues of depolarization currents are increased with the increase of annealing temperature caused byfilm-substrate interface distortion.

412

R. Waser, M. Klee, “Theory of conduction and breakdown in perovskite thin films”, Integr. Ferroelectrics, vol. 2, p. 23–
40, 1992.
413

M. Dawber, K.M. Rabe, J.F. Scott, “Physics of thin–film ferroelectric oxides”, Rev. Mod. Phys., vol. 77, p. 1083–1130,
2005.

ISAF-P4D-60 ___________________________________________________________________________________________________________________

Simultaneous piezoelectric and ferroelectriccharacterization of thin films for MEMS actuators
Andrea Mazzalai1, Davide Balma1, Nachiappan Chidambaram1, Paul Muralt1
1

Ceramics Laboratory, École Polytechnique Fédérale de Lausanne – EPFL,
Lausanne, Switzerland
Email: andrea.mazzalai@epfl.ch

Recent improvements of piezoelectric thin films, like lead zirconate titanate Pb(Zr x,Ti1-x)O3 (PZT), aredriven by high volume applications that will lead to an exponential increase of the piezo-MEMS market.
Many devices of interest like inkjet print-heads or autofocus lenses are actuators relying on thetransverse converse piezoelectric effect of ferroelectric thin films sandwiched between a parallel-plate
capacitor structure. For the purpose of film development, we need to measure the in-plane stress (T1)
and the ferroelectric polarization (P) loops. In this work, we have set up a cheap, versatile and easy to
use tool that is based on an optical probe, a charge amplifier, a XYZ manipulator stage, and suitable
cantilever samples that may have the full wafer thickness. The derivative of the obtained stress loop
gives directly the converse piezoelectric coefficient e31, f = ¶T1 / ¶E3 at a given voltage for an arbitrary
waveform.

Figure 135. Simultaneous measurement ofpolarization and stress loops at a sol-gel deposited
PZT thin film. The curves are averages of 500
continuous cycles made at a repetition rate of
110Hz.

Figure 136. Numerical derivative of the averaged
stress loop yields the effective converse
piezoelectric coefficient e31,f as a function of theelectric field.

Figure 1 shows the measurement obtained with a 1.18μm thick, sol-gel PZT thin film annealed after top
electrode deposition. The remnant effective piezoelectric coefficient e31,f was measured as 14.7 C/m2
with this set-up, and is identical to the direct e31,f measured with the set up for the direct effect (asexplained in refs 414,415). We shall present the calculation of the in-plane stress from the cantileverdeflection and report on a detailed study about the impact of the sample geometry and set-up parameterson accuracy and precision of the measurement.
414

Dubois et. al. Sensors and Actuator A 77 (1999), p. 106

415

Ledermann et. al. Sensors and Actuators A 105 (2003), p 162

ISAF-P4D-61 ___________________________________________________________________________________________________________________

Effect of Polarization on Mechanical Properties of PZT Ceramics
Yao Yu, Xusheng Wang, Xi Yao
Functional Materials Research Laboratory, Tongji University, 1239 Siping Road, Shanghai200092, PR
China
Email: yuyao9903@126.com
Abstract: The dynamic mechanical properties (storage modulus and internal friction) of PZT-5H and
PZT-8 ceramics with temperature were investigated before and after polarization at different vibrationload of 0.1, 0.5, 1, 5 and 10Hz by Dynamic Mechanical Analysis (DMA). The Curie temperature of
PZT-5H and PZT-8 ceramics tested by DMA are 438K and 548K. The relaxation peak emerges ininternal friction curves, and their position and intensity vary in different laws for PZT-5H and PZT-8.
The relaxation processes were studied according to Arrhenius law. The activation energies of
unpolarized and polarized PZT-5H ceramics are 1.29eV and 1.36eV, the activation energies of
unpolarized and polarized PZT-8 ceramics are 1.05eV and 1.08eV.

iF. Cordero, F. Trequattrini, F. Craciun, and C. Galassi, J Phys Condens Matter 23, 415901 (2011).
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