bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoacoustic Measurement of CdS by Transparent Transducer Method
Authors: Hata Tomonobu , Sato Yasusi , Nagai Yoshiaki , Hada Tosio
Published: March 2014

This paper is concerned with the theoretical and experimental study of photoacoustic (PA) spectroscopy using a transparent transducer. When the light beam is illuminated from the sample surface and a PA signal is detected by the back transducer, a peak and a valley are mixed in the PA spectra. When the light is illuminated through the transparent window, the heat at the surface is directly detected by the transducer and there is no geometrical limitation to detect PA signal. A PA spectra of a block sample and the different PA spectra for various sample treatments are demonstrated.
Automated Acousto-Optic Measurement System of Bulk Acoustic Waves Launched from an IDT
Authors: Hashimoto Ken-ya , Takeshita Takanori , Yamaguchi Masatsune , Kogo Hiroshi
Published: March 2014

The paper describes development of an automated acousto-optic measurement system for quantitative investigation of deep bulk acoustic waves (DBAWs) propagating in transparent materials. The system is automatically controlled by a micro-computer in which measured data are temporarily stored. The micro-computer is linked with a university host computer, so that the measured data can be numerically processed by taking account of effects of optical and acoustical anisotropies.
Detection of Near-Surface Flaws Using Linear FM Ultrasonic Wave
Authors: Jitsumori Akio , Inari Takahiko
Published: March 2014

A Method using linear FM ultrasonic wave to detect near-surface flaws and to measure distances from a surface to the flaw (flaw depth) in billets is presented. To test the ability of the detection and the measurement of this method, experiments were carried out using specimens with artificial flaws. The method was shown to be successful for artificial flaws with shapes such as slits and drilled holes formed at a 0.5 mm depth under the surface.
Analysis of Lamb Wave Propagation Characteristics in Piezoelectric Ceramic Plates
Authors: Mizutani Koichi , Toda Kohji
Published: March 2014

Numerical solutions for Lamb waves propagating in a piezoelectric ceramic plate with the poling axis normal to the free surface are described. The mechanical displacement, phase velocity and electro-mechanical coupling constant are given as a function of the product of the frequency and the substrate thickness. Numerical dispersion curves are found to be in good agreement with the measured results.
Optical Mode Conversion Device using MSSW for Microwave Signals
Authors: Bhandari Rakesh , Miyazaki Yasumitsu
Published: March 2014

An optical mode conversion device using magnetostatic surface waves (MSSW) for signals in the 1–20 GHz range is presented. The device features light propagation in a strip-loaded waveguide and is suitable for integrated optic applications. Theoretical results of the optical mode conversion induced by MSSW in the strip-loaded waveguide are given. Further, for the device fabrication, growth of single crystal yttrium iron garnet film by rf sputter and the study of its optical and MSSW propagation characteristics is reported.
MHz VCO Resonators with ZnO/ELINVAR Structures
Authors: Fujishima Satoru , Kasanami Toru , Nakamura Takeshi , Matsumoto Ikuo
Published: March 2014

New piezoelectric resonators made of ZnO/ELINVAR structures have been developed for 3.58 MHz TV oscillators by utilizing expanding vibrations.
In addition to superior features such as a miniature structure, low production cost and achievement of high productivity, the resonators possess a frequency pulling range several times as wide as a conventional 3.58 MHz TV resonator.
Trimmer-less, adjustment-free TV chroma circuits have been realized by the incorporation of the new resonators.
Investigation of an Equivalent Circuit for a Surface-Acoustic-Wave Double Electrode
Authors: Kojima Toshihiro , Shibayama Kimio
Published: March 2014

An equivalent circuit for a surface-acoustic-wave (SAW) double electrode is proposed, and from this circuit the three-port admittance parameter for the N-pair electrode is derived in closed-form. The validity of this circuit is discussed from the radiation and reflection characteristics. A detailed comparison of the experimental results with calculated results on LiNbO3 are shown.
New Miniaturized SAW Device in Low Frequency Range for SAW Video DOC System in Home VTR
Authors: Yamada Jun , Miura Kuniaki , Fujita Yuuji , Shiomi Makoto
Published: March 2014

A new dropout compensation method called the SAW video DOC system has been developed, corresponding to the stream of high density magnetic recording. The purpose is to improve the signal-to-noise ratio and the characteristic of dropout compensation for the palyback signal in home video tape recorders. A wide band SAW device in low frequency range of the key device in the system is miniaturized and practically can-packaged by newly developed techniques: the reduction of finger pairs, new ultraviolet curable polymeric resin and suppression of undesired wave response. In consequence, almost complete dropout compensatin and improvement of the 2.5 dB signal-to-noise ratio can be achieved in a playback video signal.
Studies on Ultrasonic Welding of Ring Shape Weldment with Two Vibration Systems
Authors: Tsujino Jiromaru , Ueoka Tetsugi , Yanagihara Toshiaki , Takahashi Minoru , Goto Nobuhiko , Masuda Yoshiaki
Published: March 2014

Ultrasonic welding of a ring shape weldment with two vibration systems is proposed and studied. The vibration directions of the upper and lower welding tips are crossed at a right angle. The upper and lower vibration systems are driven by independent controllers and 2 kW and 5 kW power amplifiers. Specimens used were 18 mm diameter rings with a flange and circular plates of anticorrosion aluminum alloy. Using the welding system with two vibration systems, these specimens were successfully welded with about an 18 mm diameter and 0.5 mm to 1 mm wide ring shape weldment.
Acoustic Microscopy of Ceramics Indentation Fracture
Authors: Yamanaka Kazushi
Published: March 2014

Subsurface cracsk in ceramics introduce by Vicker indentation were examined by acoustic microscopy. The average length and initiation probability of subsurface lateral cracks were measured from acoustic images and found to depend more significantly on the material used than those of surface breaking radial cracks. The ratio of fracture toughness K
C for lateral fractures to fracture toughness K
IC for radial fracture also varied depending on the materials used. These results revealed the difference in basic mechanisms of lateral and radial fractures in ceramics.
Improvement of the Resolution in Ultrasonic Imaging with Real-Synthetic Hybrid Aperture
Authors: Ikegami Masiki , Yamamoto Tsuyoshi , Aoki Yoshinao
Published: March 2014

The spatial resolution of conventional real aperture imaging is generally poor in comparison with that of imaging by the synthetic aperture technique, since the resolution is determined by the beam profile of transducers. In a case where the beam profile is not sharp, there is a possibility of improving the resolution by the synthetic aperture technique. Using data of the point transfer function measured in the experiment system, we have improved the spatial resolution. The simulations, experimental results and theoretical analysis are presented.
Investigation of Linearity of Photoacoustic Characteristics on Semiconductors Measured by Michelson Interferometry
Authors: Suemune Ikuo , Yamamoto Hiroaki , Yukutake Kazutoshi , Yamanishi Masamichi
Published: March 2014

Noncontact Photoacoustic measurements with Michelson interferometry was performed on several semiconductor samples. While the input power dependence of the vibration amplitudes was linear for InP and Si samples, it was found to be sublinear on a GaAs sample. The main factor for the sublinearity is discussed.
Observation of Surface Roughness by PAS using Transparent Transducer and Photothermal Deflection Sepectroscopy (PDS)
Authors: Hata Tomonobu , Hatsuda Tsuguyasu , Kawakami Makoto , Sato Yasushi
Published: March 2014

This paper is concerned with the experimental study of photoacoustic spectroscopy (PAS) using a transparent transducer and photothermal deflection spectroscopy (PDS).
The amplitude and phase of PA and PD signals are observed for differen surface roughness (etched, polished, and roughed) of the example semiconducting CdS. There are no substantial differences between PAS and PDS. Additional signal increase caused by the damaged surface layers is observed at wavelength longer than the absorption edge. The phase signals reflect information of the depth and arc less affected by the noise.
Secondary Photoacoustic Spectra of CdS: Cu by Gas-microphone Method
Authors: Wada Hideo , Yoshioka Hideyuki , Morimoto Jun , Miyakawa Toru
Published: March 2014

A new technique for PAS was proposed where the secondary steady light (λ2) modified the primary signal at wavelength (λ1). This technique was applied to the CdS: Cu system. Quenching and enhancement of PAS by the secondary light was observed depending on the absence or introduction of Cu impurities. The importance of the nonradiative decay process from a Cu related level to the native acceptor level was thus clarified.
Dispersion of Guided Longitudinal Sounds Propagated in a Rod with Longitudinal Piezoelectric Coupling
Authors: Ikeda Takuro , Inawashiro Sakari
Published: March 2014

The dispersion of guided acoustic waves in a piezoelectric rod with longitudinal-effect coupling was investigated. A lengthwise depolarizing field associated with the longitudinal sound leaks out of the rod in the long-wavelength range. A dynamical depolarization is discussed in comparison with the preceding approximation.
Photoacoustic Microscopic (PAM) Images of Some GaAs Wafers
Authors: Kasai Masanobu , Sawada Tsuguo , Gohshi Yohichi
Published: March 2014

Non-destructive inspections of some GaAs semiconductor devices were carried using a home-made photoacoustic microscope (PAM). PAM images of a Zn-doped region and dislocations of GaAs wafers were particularly discussed in this paper.
Mechanical Loss and Depolarizing Field in a Piezoelectric Medium
Authors: Ikeda Takuro
Published: March 2014

The mechanical loss in a piezoelectric medium has been discussed in relation to a depolarizing-field effect from the macroscopic point of view. Here are birefly described the phases of complex constants, the mechanical loss associated with a sound, the mechanical and electrical conditions in resonators and the dispersion in conductive media. The description is quite formal and does not intend to review microscopic pictures for internal frictions. Applications of the present method are shown by some examples.
Molecular Relaxation Study by Ultrasonic Spectroscopy
Authors: Ozawa Harue , Choi Pak-Kon , Takagi Kenshiro
Published: March 2014

The ultrasonic velocity and absorption were measured over the frequency range from 3 MHz to 5 GHz at 20° and 30°C in liquid cis and trans-dichloroethylene. Two relaxation regions were found in the velocity-dispersion spectrum of trans-dichloroethylene, one centered at 450 MHz and the other around 20 GHz, and were analyzed in terms of vibrational-translational relaxation effect. All the fundamental vibrational modes of this molecule are categorized into two groups with different relaxation times of ∼10 ps and 430 ps. The relaxation was found also in cis-dichloroethylene.
Radiation of Ultrasonic Impulse by Pseudo-Inverse Filtering in DFT Domain
Authors: Endoh Nobuyuki , Takase Atsuhiko , Nishiyama Shinji , Kawakami Yoshiroh
Published: March 2014

A radiation method is described which uses a pseudo-inverse filtering in DFT domain. A short ultrasonic pulse.such as a one cycle sinusoidal wave can be radiated using an ordinary PZT transducer. Experiments are carried out in both the transmission system and the pulse echo system. A clear direct pulse of 2 MHz without ringing is received by this method. Also obtained are one cycle sinusoidal echo pulses of a plate. The frequency dependent attenuation is compensated in the media. The experimental results confirm the validity of this method, making it seem applicable to ultrasonic diagnosis.
Frequency Spectrum of CdS Acoustic Domains for Acoustic Domain Injection Technique
Authors: Tokunaga Yoshiaki , Shimotani Toshiaki , Aiba Susumu , Ishiguro Masakazu
Published: March 2014

The purpose of this paper is to study the frequency spectrum of the CdS acoustic domain generator to measure the physical parameters of II-VI or III-V compound semiconductors. It is concluded that the low frequency fluxes below 1 GHz are caused by the piezoelectric shock in the high resistivity region due to insufficient ohmic contact near the cathode electrode.
Ultrasonic Transducer Composed of Two Piezoelectric Layers with Variable Weighting
Authors: Yamamizu Shuichiro , Chubachi Noriyoshi
Published: March 2014

Two different piezoelectric layers with alternate vibrating polarity are stacked to compose wideband ultrasonic transducers. With this construction, the amplitude and the phase of applied voltage for individual piezoelectric layers can be adjusted so that we can provide variable weighting for the transducers to obtain a wideband vibrating mode.
In this paper, the construction of the transducer is proposed and its theoretical analysis is described. Experimental results performed at a frequency around 4 MHz are further demonstrated with a comparison of the theory.
Ultrasonic Pulse Transmission/Echo Technique for Sound Velocity Measurements in High Temperature and High Pressure Liquid Metals
Authors: Suzuki Kenjiro , Fujiwaka Setuya , Inutake Masaaki
Published: March 2014

We report the details of an ultrasonic pulse transmission/echo technique which has been newly developed for sound velocity measurements in liquid metals up to temperatures around 1600°C and pressures around 2000 bars. The results of sound velocity measurements in the metal-nonmetal transition region of Hg near its critical point (T
cr=1480°C, P
cr=1600 bar) are also reported.
Frequency and Time Sources-Past, Present, and Future
Authors: Ballato Arthur
Published: March 2014

Landmarks in the history of frequency control and timekeeping are briefly described. Technologies involved in the latest classical and quantum mechanical standards are then considered, with a discussion of present capabilities. The paper concludes with projections of future areas of work.
Accuracy of Gated RF Pulse Measurement
Authors: Hashimoto Ken-ya , Yamaguchi Masatsune , Kogo Hiroshi
Published: March 2014

It is theoretically shown for the gated RF pulse measurement method how obtainable frequency resolution, dynamic range and amplitude accuracy are affected by gating and sampling pulse widths. Emphasis is laid on the situation where, to separate various closely spaced responses, either gating or sampling pulse width needs to be shorter than the impulse response length of the device concerned. The result has shown that so long as the device geometry permits the separation of a specied response, the sampling pulse width rather than the gating pulse width should be shortened.
Influence of Nonlinear Acoustic Effect on Spectral Estimation of Echo
Authors: Ueda Mitsuhiro , Mizuno Isao
Published: March 2014

An echo scattered by a plane,reflector is often used as a reference signal in ultrasonic signal processing techniques. Recently we have realized that the spectrum of the echo scattered by the plane shows frequency dependent variations as the reflectivity of the plane is changed. This phenomenon comes from the nonlinear acoustical effect of the medium since the intensity of the echo is solely dependent on the reflectivity of the plane. Consequently it can be removed easily by transmitting a sufficiently weak ultrasonic pulse. In the case of weakly scattering objects, however, we must transmit a
rather strong ultrasonic pulse. A new technique is proposed in this paper in which the echo signal, which can be used as the regerence signal even at strong ultrasonic radiation, is synthesized using echoes scattered by a thin column and a thin plate. Some experimental results which show the usefulness of the technique are also presented.
Coupled Ferroelectric-Ferroelastic Materials Including Tetravalent Elements
Authors: Thoret Jean , Launay Suzanne , Simon Annie , Ravez Jean
Published: March 2014

Lead has been substituted for cerium, thorium or uranium in Pb2.5 Nb5O15 and Pb2KNb5O15. Six phases with formula Pb2.5-2x
M
x
Nb5O15 and Pb2(1-x)M
x
KNb5O15 (M=Ce, Th, U) and tungsten bronze structure have been obtained. A cationic nonstoichiometry in the A and B sites appears for x>0. These phases have coupled ferroelastic-ferroelectric properties. The spontaneous strain and the Curie temperature decrease as lead is replaced by cerium, thorium or uranium.
A New Lead Perovskite Y5S Dielectric for Multilayer Ceramic Capacitor
Authors: Yamashita Youhachi , Furukawa Osamu , Harata Mitsuo , Takahashi Takashi , Inagaki Katsumi
Published: March 2014

A new ceramic dielectric, based on a lead zinc niobate for multilayer ceramic capacitor (MLC) has been developed according to Y5S specifications in EIA standard. The dielectric material, fired at 1,000–1,050°C, exhibits relative permittivity of 6,500, dissipation factor of 0.7%, RC products (resistance times capacitance) of 30,000 MΩµF at 25°C and 10,000 MΩµF at 85°C, respectively. An MLC, employing the dielectric material with 80Ag/20Pd internal electrode, has a small capacitance change of -20% at 2 kV/mm and 30 kV/mm breakdown voltage. Capacitance temperature change is -19% from -30 to +85°C. The new dielectric is a promising material for use as a replacement for conventional BaTiO3 based dielectric material for MLC.
Biological Systems as Pyroelectric Detectors and Transducers
Authors: Athenstaedt Herbert
Published: March 2014

Nerve tissue and sensory receptors can act as PE detectors and transducers. Test object for the nerve tissue measurements was the Nervus opticus (N.o.), cow, for sensory receptors the ear of the locust Locusta migratoria. The N.o. has PE properties and reacts to rapid changes of temperature and pressure with voltage responses analogous to those of nonbiological PE materials. The same is true for the mechanoreceptor (insect ear) which was investigated. Artificial models of sensory receptors (sensitive component: a PE material) are presented; their PE and PZE voltage responses are similar to those of real receptors in living animals.
Far Infrared Reflection Spectra of Ba(ZnTa)O3–BaZrO3 Dielectric Resonator Material
Authors: Wakino Kikuo , Sagala Djuniadi A. , Tamura Hiroshi
Published: March 2014

Ba(Zn1/3Ta2/3)O3–BaZrO3 dielectric ceramic material has a extremely low dielectric loss at microwave frequencies. In order to investigate the lattice vibrations of the system Ba(Zn, Ta)O3–BaZrO3, far infrared reflection spectra were measured from 50 to 4000 cm-1 at room and low temperature using a Fourier transform infrared spectrometer. These data have been analyzed by the classical dispersion theory. The damping constant of these materials are discussed. The dielectric characteristics at microwave frequency calculated from the dispersion parameters are in preferable agreement with the measured values.
Polarization-Optical Domain Study of the Ferromagnetic/Ferroelectric/Ferroelastic Phase of Co3B7O13I
Authors: Clin M. , Rivera J. P. , Schmid H.
Published: March 2014

Measurements of the spontaneous birefringence between 200 K to 10 K are reported. The symmetry of the ferromagnetic phases below 38 K is determined and consistent with Shubnikov point group m'm2'. A possible mechanism associated with the 28 K magnetic transition is proposed.
Magnetoelectric and Magneto-Optical Measurements on Nickel-Bromine Boracite Ni3B7O13Br
Authors: Rivera J.-P. , Schaefer F.-J. , Kleemann W. , Schmid H.
Published: March 2014

Various anomalies of Faraday rotation, magnetoelectric coefficient α23 (T), α32 (T), coercive field and birefringence of three principal cuts as well as new direct observations of magnetic domains of NiBr boracite single crystals complete the knowledge of phase transition in the following way:

(4̄3m1')-398 K-(mm21')-29 K-(m' m2')-21 K-(1)
Bibliography of Ferroelectrics on a Computer System
Authors: Toyoda Koichi , Shiozaki Yoichi
Published: March 2014

Compilation of the data-base on a computer system has being continued, which includes entirely the bibliography on the ferroelectrics and their related compounds and phenomena well known as TOYODA BIBLIOGRAPHY. This is a brief report on the present situation about the data-base. Also introduction of a searching program is made. Changes of manners expressing phenomena and substances related with several topics are observed. A few examples are reviewed.
Study of Soft Modes in Ferroelectrics by Hyper-Raman Scattering
Authors: Vogt H.
Published: March 2014

Hyper-Raman scattering is shown to be a useful spectroscopic method for studying odd-parity phonons in centrosymmetric crystals. We review recent results obtained for oxygen perovskites in their cubic paraelectric phase. Attention is focused on the soft modes which are Raman forbidden and difficult to observe by far-infrared reflection spectroscopy. We also include hyper-Raman spectra of alkali halides to illustrate principal features of hyper-Raman scattering.
Application of Pyroelectricity of LiTaO3 for Infrared Detectors
Authors: Yokoo Toshiaki , Shibata Kenichi , Kuwano Yukinori
Published: March 2014

We developed a new structure (PEC structure) pyroelectric IR detector using LiTaO3 single crystal. The detector with this structure has good performance, high reliability and is suited to mass-production. In addition, we fabricated a new IR detector structure containing both the chopper and the pyroelectric element in the same package (M-type detector). The structure and the characteristics of these detectors are described.
Incommensurate Phases of Quartz
Authors: Doling G.
Published: March 2014

The properties of the incommensurate (inc) phase of quartz are briefly recalled and the new studies performed during the last year are presented. When a symmetry breaking uniaxial compressive stress is applied along Y axis, another inc phase appears, with a single modulation wave along Y axis. New inelastic neutron scattering experiments indicate that the origin of the inc phases of quartz come probably from a gradient interaction between the optical soft mode and acoustic modes. Finally simultaneous measurements of birefringence and of γ-ray diffraction have shown the existence of irreversible effects (thermal hysteresis, pinning, memory effects, oscillatory behavior).
Ferroelectric Composites
Authors: Newnham R. E.
Published: March 2014

Some of the underlying ideas governing composite ferroelectrics and their applications are reviewed: sum and product properties, combination properties and the figure of merit, three-dimensional connectivity patterns leading to field and stress rearrangement, boundary conditions in composites, the symmetry of composite materials and its influence on physical properties, the importance of periodicity and scale in ferroelectric composites, the effect of ferroelectric phase transitions on inter facial phenomena, thermistor effects arising from coupled phase transformations, polyohromatic percolation and the poling of composites through the use of coupled flux paths, electrostriction and other non-linear phenomena, and the important role that porosity and inner surfaces play in many composites.
Analysis of Landau Potentials for Six-Dimensional Order Parameters and Realization of Non-Maximal Isotropy Subgroups
Authors: Kim Jai Sam , Hatch Dorian M. , Stokes Harold T.
Published: March 2014

We have classified continuous phase transitions in physical systems whose order parameter transforms as a six-dimensional representation of a space group. The Landau potential is minimized using Kim's geometrical method and using a table of isotropy subgroups obtained by Stokes and Hatch. The procedure is illustrated in four examples. The complete lists of stable phases for these examples are presented along with the corresponding regions in coupling constant space for each stable phase. Many interesting counter-examples to the maximality conjectures are found.
Lattice Defects and Critical Exponents for Structural Phase Transitions
Authors: Mayer I. O. , Sokolov A. I.
Published: March 2014

The critical exponents for structural phase transitions in defect crystals with a scalar order parameter are evaluated. In accordance with the Harris criterion the critical behavior of these systems should be strongly influenced by lattice defects. We find the critical exponent γ and the Fisher exponent η by the 3D-renormalization group method combined with a resummation technique applied to the three-loop field theoretical expansions. The values obtained differ from those of the pure Ising model: γ=1.325, η=0.022 and β=0.302.
Chaotic Response of a Permanent Dipole
Authors: Inoue Masayoshi , Kawaguchi Takahito , Fujisaka Hirokazu
Published: March 2014

A dynamical behavior of a rotatable permanent dipole with a polar axis driven by a periodic electric field is investigated theoretically. In a weak field, the dipole approaches one of stable equilibrium points, namely there is no response. With increasing the field the equilibrium points become unstable and limit cycles appear. In a strong field, the dipole moves chaotically and the chaos induces a diffusive motion in the angle space. Diffusive and intermittent aspects of the chaotic motion is analyzed with the aid of a new characteristic exponent.
Ferroelectric Phase Transitions in PZT with Octahedral Tilts
Authors: Halemanet T. R. , Haun M. J. , Cross L. E. , Newnham R. E.
Published: March 2014

The lead zirconate-titanate solid solution exhibits ferroelectric phase transitions involving tilts in its oxygen octahedral chains. A theory based on the Landau-Ginsburg-Devonshire formalism has been developed and numerical calculations have been made for the Pb Zr0.9 Ti0.1 O3 system. This approach involves expansion of the Gibbs free energy as a power series with polarization and tilt angle as order parameters. The results support the view that transitions are of first order in this system.
Ferroelectric Behavior and Phase Transition at 785 K in Pb5W3O9F10
Authors: Ravez J. , Abrahams S. C. , Marsh P. , Arquis S. , Chaminade J. P.
Published: March 2014

The new oxyfluoride Pb5W3O9F10 is found to crystallize in the tetragonal system with space group 14 and a=14.583, c=7.365 Å. The crystal structure is closely related to that of SrAlF5, previously shown to exhibit ferroelectric behavior. Generation of second harmonics in an atomic arrangement that readily allows reversal of the spontaneous polarization, a calculated Curie temperature of about 800 K, the experimental detection of a reversible phase transition at 785 K, a rapid rise in dielectric permittivity that reaches a maximum at the Curie temperature with a corresponding minimum in loss tangent, provide a set of sufficient and necessary conditions for ferroelectricity in Pb5W3O9F10.
The Effect of the Hydrostatic Pressure on the Antiferroelectric Transition of Pb(Mg1/2W1/2)O3
Authors: Yasuda Naohiko , Fujimoto Sanji , Yoshimura Tsunenori
Published: March 2014

The dielectric properties of Pb(Mg1/2W1/2)O3 were measured at various pressures up to 8 kbar. With increasing pressure p, the antiferroelectric transition temperature T
n decreases with dT
n/dp=-3.8±0.2°C/kbar, the extrapolated Curie-Weiss temperature T
0 increases with dT
0/dp=1.4±0.2°C/kbar, and the maximum value of the permittivity ε, ε
max, is almost constant below 4 kbar and then increases. This increase in ε
max with p is associated with the decrease in the difference Δ
T(=T
n-T
0) with p. The Δ
T extrapolates to zero at p
t≈18 kbar where the change from the antiferroelectric transition to the ferroelectric one is expected. The dielectric properties are interpreted in terms of a phenomenological theory.
Study of Phase Transition in Doped LiNbO3 Crystal by Optical Method
Authors: Jiaping Chen , Lamei Wang
Published: March 2014

Three kinds of LiNbO3 crystal, congruent composition, Mg2+ doped, and Mg2+ doped in Li1+ rich crystal, respectivily, have been grown by czochralsky method.
The phase transition of these crystals was studied with optical method in the 20–200°C range. The results of optical observation are in accord with the results of scanning curve for Δ
n. The transition temperatures for three samples are 70–90°C and 110–120°C; 75–95°C and 125°C; 95° and 145°C, respectively. Thus it can be seen that the transition temperature of LiNbO3 crystal increases with the increase of doping content of either Mg2+ or Li1+.
Isotope Effect in BaTiO3 Phase Transition
Authors: Hidaka Takehiko , Oka Kunihiko
Published: March 2014

The isotope effect of Ti on the ferroelectric curie temperature has studied when the (48Ti) in BaTiO3 is replaced with the light isotope (46Ti). Curie temperature of Ba46TiO3 is found to be 131–133°C whereas that of Ba48TiO3 is 121–122°C. the result is surprising because the Curie temperature of light-isotope-rich sample is usually lower than that of heavyisotope rich one in contrast to our result in BaTiO3.
High-Resolution X-Ray Diffraction Study of Structural Phase Transition in SrTiO3
Authors: Okazaki Atsushi , Soejima Yuji , Ohama Nobuhiko , Müller K. Alex
Published: March 2014

Recent experiments on the 105 K transition in SrTiO3 by means of the high-angle double-crystal X-ray diffractometry (HADOX) are presented and discussed. The temperature dependence of the Bragg peak-width shows two anomalies: a peak in the temperature range T
c±2 K and a gradual increase over a range of about 10 K below T
c. The former is due to critically enhanced fluctuation and is connected with the precursor behaviour of the lattice constant. The latter is attributed to a change in mosaicity and is consistent with an anomaly in the intensity vs. temperature relation. By combining HADOX with the use of white X-rays and an energy sensitive detector, all the results mentioned above are found being common in the region with the depth from the specimen surface 1 to 57 µm, and regarded as representing bulk behaviours.
Soft-Mode Contribution to the Refractive Index of SrTiO3 and KTaO3
Authors: Kleemann W. , Schäfer F. J.
Published: March 2014

The non-linear temperature dependence of the refractive index n(T) of SrTiO3 and KTaO3 between 300 and 800 K is attributed to the temperature dependence of the ferroelectric soft-mode frequency. n(T) of KTaO3 is satisfactorily described in the range 4 K <T<800 K by a Debye function superimposed by a soft-mode Sellmaier term. In SrTiO3 additional contributions due to the antiferrodistortive phase transition are found around T
c=105 K. They are analyzed within the Ornstein-Zernike approximation.
Quantum Ferroelectricity in (Cd, Pb)2(Nb, Ta)2O7
Authors: Clark C. F. , Lawless W. N. , Bhalla A. S.
Published: March 2014

Quantum ferroelectricity has been induced for the first time in a pyrochlore structure. Starting with the known ferroelectric Cd2Nb2O7, (T
c∼185 K), the transition temperature can be lowered to 0 K by a combination of Pb substitutions on the A-site and Ta substitutions on the B-site. The dielectric constants of the resulting materials have several of the typical characteristics of known quantum ferroelectrics which are all perovskites. There are, however, differences in the dielectric behavior compared to the perovskites and to renormalization-group theory results.
High Speed Optical TIR Switches Using PLZT Thin-Film Waveguides on Sapphire
Authors: Higashino Hidetaka , Kawaguchi Takao , Adachi Hideaki , Makino Toshihiko , Yamazaki Osamu
Published: March 2014

We propose a new structure of the PLZT thin film optical TIR (Total Internal Reflection) switches with strip loaded type waveguides. Using these switches, we have achieved 2 GHz intensity modulation of LD light (0.83 µm) and 1 km optical fiber transmission. Both lumped constant electrode and traveling wave electrode were examined up to 26.5 GHz. From the calculation of velocity mismatch between the modulating wave and the light wave, it is estimated that the modulation bandwidth of these switches will be more than 100 GHz.
Optical Effect of Fe3+ in BaTiO3 Single Crystals and Holographic Applications
Authors: Ormancey G. , Jullien P. , Benomar W. Ousi , Semanou Y. , Lompré P. , Beaucamps Y. , Godefroy G.
Published: March 2014

Various iron doped BaTiO3 single crystals were grown by the pulling method, absorption dielectric permittivity, conductivity, photo-conductivity, crystallographic parameters, refractive index, birefringence... were measured. Then, electrooptical coefficients, holographic efficiency and optical sensibility were studied. A large increase (about 1000) of the holographic efficiency and the optical sensibility were shown for a crystal with 0.075% at Fe; for the same concentration the electrooptical coefficient is multiplied by 7.5 and the space charge field by about 100, the tetragonality (c/a–1) of the unit cell is maximum. Optimisation of all the typical parameters is necessary to get these large effects in BaTiO3: Fe crystals.
Epidermis of Animals and Plants as a Pyroelectric Detector and Transducer
Authors: Athenstaedt Herbert
Published: March 2014

The epidermis, the outermost cell layer of animals and plants totally covering the organism, reacts on its whole surface with voltage responses of pyroelectric (PE) nature to rapid changes of distinct physical influences of the environment (e.g. temperature, pressure). The voltage/time-course of the PE responses depends on dX/dt (X, external influences, e.g. temperature). The PE responses of animal and plant epidermis are corresponding and analogous to the PE responses of the cell wall of the unicellular organism, green alga Valonia utricularis. The epidermis of living animals and plants thus functions as PE detector and transducer. Analogous properties are supposed to exist in the cell walls of other unicellular organisms, too.
Anisotropic Resistivity under Uniaxial Pressure in PTC Ceramics
Authors: Igarashi H. , Michiue M. , Okazaki K.
Published: March 2014

Two kinds of PTC ceramics with the same Curie point and with different temperature dependence of resistivity were prepared. Pressure dependence of resistivity in the parallel and perpendicular directions to uniaxial compression was measured. Anisotropy in piezoresistance was found, and significant hysteresis in the pressure-resistance curve which was not seen under hydrostatic pressure was observed. Change of piezoresistance was closely related to temperature dependence of resistivity, however, it is not able to interpretate by the stress-induced shift of the Curie point. Temperature dependence of piezoresistance was relatively monotonous even if near the Curie point.
Infrared Phonon Spectra of BaPb1-xBixO3
Authors: Uchida Shin-ichi , Tajima Setsuko , Masaki Atsushi , Takagi Hidenori , Sugai Shunji , Kitazawa Koichi , Tanaka Shoji
Published: March 2014

Infrared reflectivity spectra of BaPb1-x
Bi
x
O3 in the semiconducting phase (x≧0.4) are investigated. Four optical phonon bands are observed in the spectrum of BaBiO3. The oscillator strength of one phonon mode is found to decrease with increase of Pb composition. This is interpreted as a strong evidence for the charge disproportionation state which makes the neighboring Bi sites inequivalent in BaBiO3. It is suggested that such state is also responsible for the semiconductivity of the alloys.
Nearly Degenerated Metastable States around Phase Transitions in RbLiSO4
Authors: Konishi Hiroyuki , Noda Yukio , Yamada Yasusada
Published: March 2014

RbLiSO4 has many complicated phases with long period modulations along the c-axis. We have investigated the X-ray scattering spectra along the c
*-direction in the vicinity of the phase boundary of Phases IV, V and VI, and the time development of spectra in the IV-VI phase transition process. The X-ray scattering spectra in equilibrium state strongly depends on the crystal treatments or its history of the external conditions. Spectra observed transiently in the phase transition process between Phase IV and Phase VI shows the similar characteristics to that of the spectra observed with the equilibrium measurement after the crystal was treated with special way. These results suggest that RbLiSO4 has many metastable states which are almost degenerate to the true stable state energetically.
Electric Field Dependence of Thermal Properties in TGS Doped with L-Alanine
Authors: Cerro J. del , Ramos S.
Published: March 2014

The specific heat of TGS doped with L-alanine has been measured at several applied electric fields. The data are compared with those which we have previously obtained in pure TGS. From the values of specific heat jump and transition width, the equivalence between both bias E
b and external fields is deduced. When a reverse field lower than E
b is applied, the specific heat of LTGS is not modified.
The Lack of a Stable Fixed Point as a Sufficient Condition for Phase Transitions to be First-Order: The n=6 Test.
Authors: Meimarakis E. , Tolédano P.
Published: March 2014

The full set of Landau expansions associated to six-component order-parameters are given for continuous, structural and magnetic transitions between strictly periodic structures. The renormalization-group recursion relations are solved for the corresponding effective Hamiltonians. Only two Hamiltonians are shown to possess a stable fixed point. The conjecture claiming that the absence of a stable fixed point for a given system, necessarily corresponds to the induction of a first-order transition by fluctuations, is tested at the light of the available experimental data.
Ferroelectric Properties of N(CH3)4HSO4·H2O
Authors: Suzuki Haruhiko , Shimizu Fuminao , Yamaguchi Toshihisa , Sawada Shozo
Published: March 2014

The ferroelectricity in the crystal obtained by the evaporation of aqueous solution of N(CH3)4HSO4 has already been reported by us. Recently, by the thermo-gravity analysis, it was found that most of the crystals are the hydrated crystal N(CH3)4HSO4·H2O containing one molecule of water of crystallization and that some crystals contain only about 0.3 molecule. The latter crystals are considered to be mixture of the hydrated crystal and the completely anhydrous one N(CH3)4HSO4, which has not been obtained yet. The hydrated crystal undergoes phase transitions at -104°C and around 40°C, and the completely anhydrous crystal can be said to show transitions around -70, -42, 42 and 129°C. The former shows the ferroelectricity in the temperature range from -104°C to about 40°C and the latter seems to show also the ferroelectricity in nearly the same temperature range.
New Piezoelectric Materials for Ultrasonic Transducers
Authors: Takeuchi Hiroshi , Jyomura Shigeru , Nakaya Chitose
Published: March 2014

Two types of piezoelectric ceramics with large electromechanical anisotropies (planar coupling factor k
p is much less than thickness dilatational coupling factor k
t) have been developed for use as high-frequency ultrasonic transducer materials: modified lead titanate ceramics (Pb, Sm)(Ti, Mn)O3 and ferroelectric PbZrO3 ceramics modified by adding small amounts of Pb(Mn1/3Nb2/3)O3 and PbTiO3. These new ceramics have a large k
t and k
t/k
p. PZT/polymer piezoelectric composite sheets have also been developed for use in medical transducers. These composite sheets were fabricated using a “dicing and filling” technique. The resulting composites are highly flexible and show both a large k
t and a low acoustic impedance.
Order-Disorder Phenomena in K2 Ba(NO2)4
Authors: Unruh H.-G. , Brückner H. J.
Published: March 2014

Dielectric measurements at radio- and microwave-frequencies reveal relaxations of the permittivities κa and κc, which are attributed to reorientational motions of crystallographically inequivalent nitrite-groups. Characteristic frequencies of the dynamics and activation energies of the flipping NO2-groups are determined. Implications for the phase transition at about 200 K are discussed.
Critical Behaviour in the Dielectric Constant and the Ultrasonic Velocity in CsH3(SeO3)2
Authors: Komukae Masaru , Hirayama Yusei , Waki Kenichiro , Makita Yasuharu
Published: March 2014

The dielectric constant (ε) and the ultrasonic velocity (V) of antiferroelectric CsH3(SeO3)2 were measured at 100 kHz and 10 MHz respectively near the phase transition point (T
N).
It was found that the temperature where the anomalous peak of ε is observed is higher than T
N by 2.5°C. The critical index for the anomalous part of the velocity Δ
V observed above T
N is analyzed by the power law and is found to be ζ=0.44, while ε does not follow the power law near T
N, but it follows the Curie-Weiss law far from T
N.
Phase Transitions and Dielectric Properties of Some Monoclinic A2XY4 Crystals; Rb2ZnI4, Tl2ZnI4, and Cs2HgI4
Authors: Gesi Kazuo
Published: March 2014

Single crystals of monoclinic Rb2ZnI4, Tl2ZnI4, and Cs2HgI4 were prepared, and dielectric properties were measured. In Rb2ZnI4, two phase transitions were found at 62.4 K and 7.5 K. The dielectric constant along the b-direction shows a λ-type maximum at 62.4 K. The crystal of Tl2ZnI4 is ferroelectric along the b-direction below the Curie temperature of 209 K. The spontaneous polarization at 180 K is about 1.2×10-2 C m-2. In Cs2HgI4, the dielectric constant along the b-direction increases with decreasing temperature down to liquid helium temperature. Pyroelectricity was not observed both for Rb2ZnI4 and for Cs2HgI4.
Properties and Applications of Screen Printed Piezoelectric Films
Authors: Fu Shen-Li , Chung J. K. , Cheng S. Y.
Published: March 2014

Thick piezoelectric films are fabricated by screen printing and firing the pastes prepared with either the calcined or the sintered composition of Pb0.9875[(Zr0.52Ti0.48)0.975Nb0.025]O3. Lithium carbonate and equal amount of Bi2O3 are added as liquid phases to promote densification.
The spontaneous polarization, P
s, of the fabricated piezoelectric films ranges from 6 to 10 µC/cm2, the remanent polarization, P
r, is from 3 to 8 µC/cm2, and the coercive force lies between 1.8 to 4KV/mm.
Bimorph structure is formed by fabricating the piezoelectric film on a piezoelectric ceramic (PZT) sheet. The film and the PZT sheet are oppositely poled for buzzer application. By fabricating the piezoelectric film on stainless steel sheet directly, a new piezoelectric transducer is formed, with better performance and durability to temperature higher than 100°C.
Measurement of Piezoelectric Coefficients of ZnO Thin Film with Photoacoustic Technique
Authors: Guang Li , Qing-Rui Yin , Wei-Gen Luo , Zhi-Wen Yin
Published: March 2014

Piezoelectric coefficients e
33, e
31 of sputtered ZnO thin films are measured by photoacoustic technique. The obtained values for e
33 and e
31 are 0.81 C/m2 and -0.43 C/m2 respectively. The theoretical consideration and experimental procedures which were used to evaluate the related coefficients of ZnO thin films are presented as well.
Effective Dielectric Constant of BaTiO3-PVDF Systems
Authors: Takeuchi Manabu , Miyamoto Yoshiyuki , Nagasaka Hideo
Published: March 2014

Effective dielectric constant of heterogeneous layers, in which BaTiO3 particles are dispersed in PVDF matrix, has been studied experimentally. Two kinds of samples, fused and cast BaTiO3-PVDF layers, were prepared for dielectric measurements.
When the values of effective dielectric constant for the BaTiO3-PVDF layers were plotted against the volume fraction of BaTiO3, it was found that the experimental values were inside of the Hashin-Shtrikman bounds and fitted to the van Beek theory for both the fused and cast samples. However, the values of the shape factor D in the theory were different with each other for the fused and the cast samples, suggesting a difference in the phase distribution between the two samples.
Scaling Relations in Domain Growth: Non-diffusive 1st Order Transformations.
Authors: Axe J. D.
Published: March 2014

We review some elementary concepts and recent progress in the understanding of first order phase transformation kinetics in systems with nonconserved order parameters. Special emphasis is given to scaling relations for domain growth in both nucleation and growth and in later coarsening stages.
Digital Displacement Transducer Using Antiferroelectrics
Authors: Uchino Kenji
Published: March 2014

Anomalous strain changes are associated with the electric field induced phase transition from an antiferroelectric phase to a ferroelectric one. PZT family ceramics Pb0.99Nb0.02[(Zr0.6Sn0.4)1-y
,Ti
y
l0.98O3 are investigated here, revealing digitalized strains or a shape memory effect. These phenomena are explainable in terms of a dielectric phase diagram. Applications are proposed for generating swing motion with a constant amplitude or mechanical clamping at the position with a narrow space.
Dielectric and Pyroelectric Properties of PbTiO3 Thin Film
Authors: Iijima K. , Kawashima S. , Ueda I.
Published: March 2014

The c-axis oriented and epitaxial PbTiO3 thin films have been prepared by rf-magnetron sputtering for the high sensitive pyroelectric infrared sensor. It was found that pyroelectric currents were detected on these films even without poling treatment. The polarity of the currents were the same in all specimens. One of these films had ε
r of 110 and y of 2.5×10-8 C/cm2·K. Temperature dependence of ε
r of the film with and without substrate were measured. Whereas the film with substrate had the broad peak of ε
r at 550°C, the film without substrate showed the sharp and large peak of ε
r at about 600°C. A substrate free thin film infrared sensor was fabricated. The vlotage responsivity and relative detectivity are 1300 V/W and 2.5×108 cm√Hz/W with bandwidth of 1 Hz at chopping freqency of 10 Hz, respectively.
Multilayer Piezoelectric Ceramic Bimorph Actuator
Authors: Fuda Yoshiaki , Murata Minoru , Matsuo Yashuyuki
Published: March 2014

Electromechanical properties have been studied for piezoelectric ceramic bimorph actuator without adhesive process, in which many internal electrodes were layered. The presently developed actuator with a size of 40 mm×12 mm×0.8 mm, shows 500µm free displacement or 60 gf clamping force by applying voltage V
1=40, V
2=-10 DCV. Increasing in layer number of internal electrodes of the actuator, leads to decrease the displacements and to increase the generative
force. The hysteresis of the actuator was not only reduced to about one third of that of the conventional type, but also both of the creep and shift phenomena were sufficently reduced.
Anisotropy in Anomalies of Hypersound Velocity and Attenuation in Ferroelectric TSCC
Authors: Hikita T. , Wang J. T. , Schnackenberg P. T. , Schmidt V. H.
Published: March 2014

From Brillouin shift and linewidth of longitudinal phonons propagating along the [100] and [001] directions of TSCC, the polarization relaxation time was calculated to be τ=3.1×10-12/(T
c-T) sec below the transition temperature T
c. The anomalies in the longitudinal phonons of the [010] propagation were carefully examined using an annealed crystal of excellent quality. No essential difference was observed between the velocities of a normal and high quality crystals. The relaxation time was deduced as a function of temperature from the observed anomalies in the velocity and linewidth. Spectra are observed for nearly forward scattering from the q\varparallel[010] phonons.
The Lattice Statics and Dynamics of Ferroelectric PbHPO4
Authors: Lockwood D. J. , Ohno N. , Nelmes R. J. , Arend H.
Published: March 2014

Neutron and x-ray diffraction studies of ferroelectric PbHPO4 (T
c≃310 K) have shown that the proton ordering has the same temperature dependence as the spontaneous polarization, P
s, while the heavy-atom structure varies by a relatively small amount and remains noncentrosymmetric above T
c. A Raman study of PbHPO4 has revealed a soft mode whose frequency has a temperature dependence that does not follow P
s. Several of the hard modes lose intensity continually with increasing temperature and are still discernible at 320 K. A direct comparison with the structural data shows that this behaviour is derived from the heavy-atom displacements, and the acentricity of the crystal structure for T>T
c is confirmed. The results suggest the transition involves simply an ordering of the protons, probably accompanied by some anomaly in the phosphate ion motions.