bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Preparation of Nano-Sized TiO2 and ZrO2 Particles by Nanocasting with Nanoporous SiO2 and Selective Dissolution
Authors: Lee Jun , Sugi Yoshihiro , Jeong Nam Jo , Seo Gon , Cho Sung June
Published: March 2009

High surface area and uniform nano-sized TiO2 and ZrO2 were prepared readily by the
infiltration of metal alkoxides into the nanoporous SiO2, SBA-15 and the following selective
dissolution of SiO2. The obtained particles of TiO2 and ZrO2, 8.1 nm were nanocrystalline of which
the structure were anatase and tetragonal, respectively. The surface area and pore volume of the
nanocrystalline metal oxides can be increased to above 200 m2g-1 and 0.30 cm3g-1, respectively.
Sol-Gel Synthesis of GdAlO3 Buffer Layers on SrTiO3 (100) Substrates
Authors: Bang Jae Cheol , Kim Jin Hyeok , Lange Frederick F.
Published: March 2009

To identify the possibility of using GdAlO3 (GAO) as a buffer layer for YBa2Cu3O7-δ
(YBCO) coated superconductor wire, we report the result of GAO deposition on SrTiO3 (STO) single
crystal substrates by sol-gel processing. Precursor solution was prepared by dissolving stoichiometric
quantities of gadolinium hexahydrate and aluminum isoproxide in a mixed binary solvent (2-4
pentanedione:methyl alcohol=1:1). The solutions were spin-coated on STO (100) single crystal
substrates and heated at 500~1100 for 2 h in wet Ar-5% H2 atmosphere. A FESEM observation
of the surface morphology of the GAO has shown that it has a very smooth surface with a faceted
morphology indicating epitaxy. It was shown in x-ray diffraction characterization that epitaxial GAO
films with epitaxial orientation relationship of (001)[112]GAO||(100)[110]STO have been grown on
STO (100) substrates.
Effect of Colloidal Silica Contents in the Organic-Inorganic Hybrid Coatings on the Physical Properties of the Film on the Metal Surface
Authors: Kim Do Hyun , Lim Hyung Mi , Kim Sang Mok , Kim Byoung Man , Kim Dae Sung , Lee Seung Ho
Published: March 2009

The coatings composed of colloidal silica, methyltrimethoxy silane (MTMS), water, and
acid catalysts have been prepared with variation of colloidal silica contents from 0 to 20 %. All the
coatings were prepared and coated on the aluminum plate under the same condition except the
contents of colloidal silica, and the compensating contents of MTMS and water with fixed molar ratio
of MTMS and water to be 3. The physical properties were compared in terms of hardness, adhesion
strength, corrosion, wear resistance, and thermo gravimetry analysis, etc. The pencil hardness was
drastically increased with the addition of 5% colloidal silica particles and was further increased
slightly by increase of additional silica. The corrosion resistance of the coating film against alkali
solution was improved by increasing colloidal silica content, however, the acid resistance was less
affected by the content of colloidal silica.
Roles of Additives on Crystal Growth Rate of Precipitated Calcium Carbonate
Authors: Ahn Ji Whan , Park Woon Kyoung , You Kwang Suk , Cho Hee Chan , Ko Sang Jin , Han Choon
Published: March 2009

The characteristics of nucleation and the crystal growth of aragonite-precipitated calcium
carbonate in Ca(OH)2 – MgCl2 – CO2 system by a carbonation process is investigated. MgCl2, in
this study, was added in order to increase the formation yield of aragonite precipitated calcium
carbonate. Optimum conditions of the concentration of the reactants, the temperature and the
amount of additives were studied. The formation yield of calcite gradually decreased, and the
formation yield of aragonite increased with the addition of MgCl2. A higher formation yield of
above 98% for aragonite is obtained by the adding of the Mg2+ ion in a 0.2M Ca(OH)2 – 0.6M
MgCl2 – CO2 system at 80. The nucleation rate increased as the temperature decreased and as the
CO2 gas flow rate increased. The particle size and aspect ratio increased at a high temperature, a
low flow rate of gas, and a high concentration of Ca(OH)2 slurry. Small-sized aragonite was
obtained at a low temperature. The increase in crystal size with the decrease in the CO2 gas flow
rate can be explained by the decrease in the nucleation rate, in addition to the increase in the crystal
growth rate resulting from the decrease in the dissolution rate to CO3
2- ion.
Hydrothermal Synthesis of Nanosized Titania Photocatalysts Using Novel Water-Soluble Titanium Complexes
Authors: Kobayashi Makoto , Tomita Koji , Petrykin Valery , Yin Shu , Sato Tsugio , Yoshimura Masahiro , Kakihana Masato
Published: March 2009

Highly crystalline titania nano-particles were synthesized by hydrothermal method using
novel stable water-soluble titanium complexes. It was confirmed that single phase anatase, rutile and
brookite, which can be rarely synthesized as a single phase, can be obtained by varying the ligand in
the complex and pH of the aqueous solution. TEM observations and BET specific surface area
measurements had shown that these samples consisted of nanosized particles of 5~200 nm and had
high specific surface areas of 25~150 m2/g. According to UV-visible diffuse reflectance spectra,
these titania samples absorbed light in the visible region (λ > 400 nm). Photocatalytic activities in NO
oxidation reaction exhibited by synthesized titania powders under the irradiation by UV- visible light
were higher than the activity of the commercial TiO2 photocatalyst P25 (Degussa). Especially, under
illumination by only visible light of above 510 nm wavelength, photocatalytic activity of the obtained
specimens exceeded that of P25 more than four times. We also clearly demonstrated that single phase
brookite had high photocatalytic activity for NO oxidation.
Thermal Behavior of Carbon Nanotubes in Alumina Matrix Nanocomposites
Authors: Oh Sung Tag , Yoo Seung Hwa , Jang Jae Kyo , Song Chul Kyu , Choa Yong Ho , Kang Sung Goon
Published: March 2009

Thermal behavior and microstructural characterization of the CNTs/Al2O3 nanocomposites
with different relative densities were studied by TGA and SEM. The onset temperature for weight loss
corresponded to a decomposition of CNTs in TGA increased with an increase of relative density. The
activation energy for CNTs decomposition obtained by the Kissinger method increased with
increasing relative density. The difference in thermal behavior was explained by the porosity effect on
the oxidation and decomposition of CNTs.
ZnO Nanowalls and Nanocolumns Grown by Metalorganic Chemical Vapor Deposition
Authors: Kim Sang Woo , Fujita Shizuo , Yi Min Su , Kim Han Ki , Yang Bee Lyong , Yoon Dae Ho
Published: March 2009

ZnO nanowalls and nanocolumns were synthesized on Si3N4 (50 nm)/Si (001) substrates at
low growth temperature (350 and 400 oC) by metalorganic chemical vapor deposition (MOCVD) with
no metal catalysts. ZnO nanowalls with extremely small wall thicknesses below 10 nm and
nanocolumns with diameters over 100 nm were formed on the Si3N4/Si substrates relying on
MOCVD-growth temperature. It was found that ZnO nanowalls have a strong c-axis preferred
orientation with a hexagonal structure, while ZnO nanocolumns have a weak c-axis preferred
orientation with broken stacking orders in synchrotron x-ray scattering experiments. In addition,
strong free-exciton emission from the ZnO nanowalls was clearly observed in photoluminescence
measurements. On the other hand, we could not observe any emission bands from the ZnO
nanocolumn samples.
Electronic Structure and Defect States of Transition Metal Doped Rutile TiO2
Authors: Kim Yoon Suk , Lee Sung Ho , Lee Kyung Sub , Chung Yong Chae
Published: March 2009

The electronic structure and defect states of 6.25% transition metal (TM = Fe and Co)
doped rutile titanium dioxide were investigated by ab initio ultrasoft pseudopotential plane wave
method based on density functional theory. When a Fe or Co atom was substituted for a Ti site of TiO2
lattice, additional unoccupied 3d-states of TM appeared as defect states in band-gap and occupied
3d-states represented metallic behavior (half-filled states).It was found that two occupied defect states
and one half-filled defect state were the 3d-states of TM from the calculation of band decomposed
charge density. The higher unoccupied states were hybridized with unoccupied oxygen 2p-states and
located at the middle of band-gap.
Highly Sinterable Lithium Titanate Powders Fabricated by an Organic-Inorganic Solution Route
Authors: Lee Myung Hyun , Jung Choong Hwan , Lee Sang Jin
Published: March 2009

Highly sinterable lithium titanate (Li2TiO3) powder was fabricated by an organic-inorganic
solution route. Liquid-type ethylene glycol (EG) was used as an organic carrier for the metal cations.
Titanium isopropoxide and lithium nitrate were dissolved in the liquid-type ethylene glycol without
any precipitation. The dried precursor gel showed crystalline form at 300 °C and carbon-free Li2TiO3
was observed above 400 °C. The primary particle size of the carbon-free Li2TiO3 was about 100 nm,
and the structure of the crystallized powder was porous and agglomerated. The porous powder was
ball-milled and easily ground to fine particles. The powder compact was densified to 93% theoretical
density (TD) at relatively low sintering temperature of 1100 °C for 2 h. The densifed Li2TiO3 showed
a small grain size of 1.2 μm. As well, the grain size was notably increased at 1200 °C and above. After
the over grain growth, further densification was no more observed.
Characteristics of Thermal Performance in High Power LED Package with Heat Pipe
Authors: Hwang Woong Joon , Yeo Hwa Jun , Shin Moo Whan
Published: March 2009

This paper discusses about thermal performance of high power light emitted diode
(HPLED) implemented with sintered metal wick type heat pipe(SWHP). The HPLED(2.5 W)
samples were surface mounted device(SMD) package used in our experiments. The experiments were
made for SWHP with diameters of 6.0 mm. The length of the SWHP is 150 mm. The working fluid in
the heat pipes is pure water. The electrical-thermal transient technique was employed for the junction
temperature measurement. It was found that the SWHP leads to decreased of thermal resistance by 35
% compared with a simple copper bar in oil bath (forced cooling condition). Employment of copper
cap as a LED attachment was more advantageous over the phosphor bronze. After the increase of
input power, the thermal resistance of HPLED package has decreased with the increase of effective
thermal conductivity of SWHP.
Crystallographic and Magnetic Properties of Sm2Fe17N3 Films Grown by RF Magnetron Sputtering
Authors: Kim Eng Chan
Published: March 2009

Sm2Fe17Nx film magnets were prepared using a Sm2Fe17 target in a N2 gas atmosphere
using a RF magnetron sputtering technique. The effect of nitrogenation treatment such as N2 gas
pressure during sputtering, film heating temperature, N2 gas rate, and the effect of film thickness on
the microstructure and magnetic properties of Sm2Fe17Nx films were studied. Optimized magnetic
properties with film thickness 270Å, N2 gas rate 10 % and heating temperature 530°C could be
obtained. In-plane anisotropy, which was the basic goal in this study, was achieved by controlling the
nitrogenation parameters.
Factors Influencing the Sensitivity of the CDMPI Sensor
Authors: Kollu Pratap , Yoon Seok Soo , Kim Chong Oh , Kim Cheol Gi
Published: March 2009

A highly sensitive magnetic sensor using the GMI (Giant Magneto Impedance) effect has been developed. The sensor performance is studied and estimated. The sensor circuitry consists of a Square wave generator (driving source), a sensing element in a form of composite wire of a 20μm copper core electrodeposited with a thin layer of soft magnetic material (Ni80Fe20), two amplifier stages for improving the gain from the sensor element, switching mechanism, scaler circuit, an ac power source driving the permeability of the magnetic coating layer of the sensing element into a dynamic state, and a signal pickup LC circuit formed by a pickup coil and an capacitor .The results showed that for high sensitivity and resolution (10-7 T), the frequency and magnitude of the ac driving current through the sensing element each has an optimum value, the resonance frequency of the signal pickup LC circuit should be equal to or twice as the driving frequency on the sensing element, and the anisotropy of the magnetic coating layer of the sensing wire element should be longitudinal.
Functionalization of Magnetite Nanoparticles for Protein Immobilization
Authors: Kim Min Jung , An Guk Hwan , Choa Yong Ho
Published: March 2009

The surface of magnetite nanoparticles which have been prepared by coprecipitation
method was modified by carboxylic acid group of poly(3-thiophenacetic acid (3TA)). Then the egg
white lysozyme was immobilized on the carboxylic acid group of the modification of the magnetite
nanoparticles. Lysozyme immobilizing efficiency increased with increasing concentration of 3TA.
And the functionalized magnetite particles had higher enzymatic capacity than non-functionalized
magnetite nanoparticles.
Edge Shape Effect on Switching Behavior in a Small Ferromagnetic Pattern
Authors: Kwon Jae Hyun , Koo Hyun Cheol , Yi Hyun Jung , Han Suk Hee
Published: March 2009

Switching behavior and domain structure greatly depends on the edge shape of mesoscopic
patterns. In our simulation, permalloy patterns with elliptical and tapered edge need 80% and 50%
more switching field, respectively, than a rectangle for the same overall aspect ratio of four. In the
switching dynamics, vortex nucleation and its initial location play a great role in deciding switching
field. Elliptical and tapered patterns show high magnetic remanence, which is advantageous for
non-volatile device application. It is also demonstrated that small control of tapered edge makes it
possible to change the switching behavior without the variation of overall aspect ratio.
Novel Low-Temperature Synthesis and Characterization of Lithium Cobalt Dioxide for Lithium Rechargeable Batteries
Authors: Moon Seong In , Kong Ming Zhe , Periasamy Pasikkasu , Kim Hyun Soo
Published: March 2009

Lithium cobalt oxide is synthesized by a novel solution combustion procedure. In
this synthesis, a solution mixture of lithium nitrate, cobalt nitrate and glycine fuel is heated to
500, 600 and 700 °C for 3 hours to obtain an ordered crystalline-layered compound. Physical
properties of the synthesized cathode materials were evaluated using a XRD, SEM and particle
size analyzer. The charge-discharge cycling characteristics of the synthesized lithium cobalt
oxide heated at 700 °C exhibited better performance than other materials.
Characteristics of Indium Zinc Oxide Thin Films Deposited by Radio Frequency Reactive Magnetron Sputtering for Solar Cells Application
Authors: Cho Han Na , Lee Jang Woo , Min Su Ryun , Chung Chee Won
Published: March 2009

Indium zinc oxide (IZO) thin films were deposited on a glass substrate by radio frequency
(rf) reactive magnetron sputtering method. As the rf power increased, the deposition rate and
resistivity increased while the optical transmittance decreased owing to the increase of grain size.
With increasing gas pressure, the resistivity increased and the transmittance decreased. Atomic force
microscopy and scanning electron microscopy were employed to observe the film surface. The IZO
films displayed a resistivity of 3.8 × 10-4 Ω cm and a transmittance of about 90% in visible region.
Temperature Dependence of Internal Stress and Crystal Growth of Dilute Cu Alloy Films
Authors: Koike Yousuke , Inase Toshio , Takayama Shinji
Published: March 2009

Annealing behavior of dilute Cu-X alloys (adding element X = transition metal and
rare-earth metal with less than 3 at %) was investigated in terms of resistivity, internal stress, grain
growth and hillock formation. The resistivity increases with addition of impurities regardless of
kinds of adding elements. Generally, resistivity starts to decrease on annealing above 200 °C.
Among present Cu dilute alloys, Sn addition shows the lowest resistivity 2.5 μΩcm on annealing at
400 °C. However, compared with a pure Cu film, salient grain growth of present dilute alloys does
not takes place even at temperatures above 300 °C , where the grain size is nearly the same as that
of as-deposited films. In-situ surface observation using an atomic force microscope (AFM )
revealed that hillocks did not grow on cooling stage (under tension), but started to form on heating
stage (under compression). The scanning electron microscopy (SEM) observation of hillocks thus
formed in present dilute alloy films shows that the external appearance of these defects was quite
different from those observed in Al and Al alloy films. They most likely grow with a preferential
crystal plane, not irregular growth like Al and Al alloy films. The internal stresses in most of the
present as-deposited dilute Cu alloy films were nearly zero or compression of –25 to –100MPa, and
upon annealing, they started to increase in tensile manner due to thermal stresses induced by the
mismatch of the thermal expansion between substrates and deposited films. A large stress relaxation
started to occur above 250°C, associating with a large number of hillock formation.
Interface Development in Joining Yttria Stabilized Zirconia to Stainless Steel by In Situ Alloying with Ni/Ti Filler Metals
Authors: Indacochea J.E. , Beres J. , Polar A.
Published: March 2009

There is need for efficient energy conversion systems based on domestic fossil or biofuels.
Solid Oxide Fuel Cells (SOFC's) are attractive in this case, however sealing is a critical
issue in SOFC development. The purpose of this investigation is to find a procedure to seal
yttria stabilized zirconia (YSZ) electrolyte to the stainless steel electrical interconnect or gas
manifold. The seal is usually exposed to high temperatures in the range of 500 to 1000°C.
Brazing by in-situ alloying of nickel and titanium foils was performed to braze zirconia to 444-
stainless steel. Different combinations of nickel/titanium foils were used; brazing was done in
vacuum at 6 x 10-6 torr at 960°C, 1010, and 1030°C for different brazing times. The braze and
interfacial microstructures were characterized by optical microscopy, scanning electron
microscopy (SEM), and energy dispersive spectroscopy (EDS). This paper assesses the
effect of process parameters on the development and stability of the braze metal and the
interactions of the filler metal with the two substrates.
Oxidation Behavior of Mo-Si-B In Situ Composites
Authors: Yamauchi Akira , Yoshimi Kyosuke , Murakami Yoshihiro , Kurokawa Kazuya , Hanada Shuji
Published: March 2009

Isothermal oxidation behavior of Al added Mo-Si-B in-situ composites was investigated under Ar-20%O2 and air atmosphere over the temperature range of 1073–1673 K. The Al added Mo-Si-B composites ((Mo-8.7mol%Si-17.4mol%B)-1mol%Al) were prepared by arc-melting, and homogenized at 2073 K for 24 h in an Ar-flow atmosphere. The ternary Mo-Si-B in-situ composite exhibited a rapid mass loss at the initial oxidation stage and then the passive oxidation after the substrates were sealed with borosilicate glass in the temperature range of 1173–1473 K, whereas it exhibited a rapid mass gain around 1073 K. On the other hand, the Al addition significantly improved the oxidation resistance of Mo-Si-B in-situ composites at temperatures from 1073–1573 K. These excellent oxidation resistances are considered to be due to the rapid formation of a continuous, dense scale of Al-Si-O complex oxides.
Numerical Simulation of the Stress Field of Thick 7B04 Aluminum Alloy Board during Continuous Manufacture Procedure
Authors: Fang Hong Yuan , Fan Cheng Iei
Published: March 2009

Numerical simulation method is employed in the article to analyze the stress field of
thick 7B04 aluminum alloy board during manufacturing procedure of solution treatment,
calendaring and stretching. The simulation results show that the surface of the board endures
compressive stress while the core segment endures tensile stress, and the distribution of the stress is
very inhomogeneous. The calendaring procedure helps to decrease the stress and redistribute the
stress uniformly, but it also leads to stress concentration at the two ends of the board, which
engenders bad influence on the subsequent processing. The board deforms plastically when being
stretched, thus the stress decreases greatly and is redistributed uniformly.
Room Temperature Micro-Bonding of Fine Wires to Foils
Authors: Takahashi Yasuo , Maeda Masakatsu , Doki Takehisa , Matsusaka Souta
Published: March 2009

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Study on Improvement of Oxide Layer and Properties of Plasma Sprayed Alumina in Thermal Barrier Coatings
Authors: Kobayashi Akira , Shanmugavelayutham G. , Yano S.
Published: March 2009

Thermal barrier coatings (TBC) have been used to improve the efficiency of turbine
engine by providing the capability to sustain significant temperature gradient across the coating.
TBC failure occurs easily at the interface between the metallic bondcoat and topcoat. Alumina was
proposed as a potential candidate as an interlayer to improve the oxidation resistance of thermal
barrier coating due to its low oxygen diffusivity against the harsh environment. The mechanical
properties, thermal behaviour and high temperature oxidation resistance of the coatings formed by
gas tunnel type plasma spraying were investigated in this study. The results showed that this system
exhibits the improvement of mechanical properties of the coating and oxidation resistance. This
interlayer is preferred in order to minimize the detrimental effect of phase transformation of γ-
Al2O3 to α-Al2O3.
Effects of a Small Amount of Ta on Diffusion Behavior of Carbon in Molybdenum
Authors: Hiraoka Yutaka , Inoue Takeshi
Published: March 2009

Fractography was used in order to investigate the effects of Ta addition on the
diffusion behavior of carbon in molybdenum. Mo-1.5mass%Ta alloy was carburized by the
solid-state carburization process at a temperature between 1073 and 1473 K. Fracture surface of
the specimen was observed before and after the carburization process and carbon diffusion distance
was estimated from the change in fracture mode as a function of distance from the specimen surface.
Results are as follows. (1) Ta addition slightly decreased the carbon diffusion distance. (2) Ta
addition had almost no effect on the activation energy for diffusion. (3) These results suggest
preferential combination between carbon atoms and Ta atoms is only minor.
Effects of Thermal Treatment on the Structure of Eu:YAG Nanopowder
Authors: Saladino Maria Luisa , Caponetti Eugenio , Enzo Stefano
Published: March 2009

Eu:YAG nanopowder precursors were obtained by co-precipitation of aluminium, yttrium and europium nitrates solution with ammonia. The hydroxides precursors were calcined at different temperatures from 900 to 1200°C as a function of holding time (1, 2 and 6 hours). The presence of Eu3+ ions in the matrix was confirmed by Energy Dispersive X-rays analysis. X-Ray Diffraction investigation by the Rietveld method shows that the sample treated at 900°C for 1 hour is essentially the garnet phase with the minor presence of hexagonal and monoclinic metastable phases. The Eu3+ ions are incorporated into the garnet phase, as is suggested by the lattice parameter value being larger than that in literature data (homogeneous strain). For the sample treated at 900°C for 1 hour, electron microscopy observations showed agglomerates of spherical particles of mean size about 50 nm. At higher temperature treatments and for longer holding times the minority hexagonal and monoclinic phases totally disappeared. However, the lattice parameters of the cubic garnet phase gradually decreased with temperature, suggesting an expulsion of Eu3+ ions from the solid solution. Simultaneous with this, it was noted that the lattice strain reached a maximum value, but to later decrease, due to the vacancies created by the Eu species initially migrating to the surface of the coherent domains of diffraction. The lattice strain definitely decreased upon more drastic thermal treatments. Meanwhile, FEG-SEM and TEM observations on the same samples confirmed the growth of the garnet particles as a function of the thermal treatment.
The Influence of ZrO2 Containing 10% Eu 3+ on the Polyurethane Hard Domain Structure in Nanocomposites with Luminescence Properties
Authors: Ryszkowska Joanna , Zawadzak Ewelina , Zapart Piotr , Łojkowski Witold , Opalińska A. , Kurzydlowski Krzysztof Jan
Published: March 2009

This paper presents the results of studies on ZrO2 containing 10% Eu3+ as a nanofiller in polyurethane nanocomposites with luminescent properties. The nanocomposites, which are potential materials for electro-optical-electronic applications, were prepared by in-situ polymerization. Emission spectra, thermodegradation, thermal analysis and mechanical properties of polyurethane ZrO2/10% Eu3+ were investigated and the structure examined using HRSEM. The aim was to investigate the influence of the distribution of nanofillers in the composite and the structure of hard domains of polyurethanes on the relevant properties for opto-electronic applications.
Magneto-Chemical Properties of Some New Ni and Co Rare-Earth Metal Tungstates
Authors: Worsztynowicz Adam , Kaczmarek Slawomir M. , Tomaszewicz Elzbieta
Published: March 2009

New d-electron and rare-earth metal tungstates (CoRE2W2O10; CoRE4W3O16;
Co2RE2W3O14 and NiRE2W2O10) were studied by the IR and EPR spectroscopy methods. The IR
absorption bands with their maxima can be assigned to the symmetric and asymmetric stretching
modes of W-O bonds in the joint of WO6 octahedra and also to the oxygen double WOOW bridge
bonds. The wide, unstructured EPR powder spectra of these compounds and their temperature
evolution have been analyzed and interpreted.
High Throughput Screening of the Sensing Properties of Doped SmFeO3
Authors: Siemons Maike , Simon Ulrich
Published: March 2009

p-type semiconducting perovskites Sm1-xAxFe1-yByO3 (A=La, Sr, x=0, 10, 20 at%, B=Cr, Co, Mn, y=0, 10, 20 at%) were synthesised via the polyol method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to confirm the structure and morphology of the materials. Thick films of the materials prepared together with surface doped SmFeO3 (with Au, Ce, Ir, Pd, Pt, Rh, Ru) samples were electrically characterised using high throughput impedance spectroscopy (HT-IS). The gas sensing behaviour was tested at temperatures ranging from 200 to 500°C. For La and Cr doping a model describing a correlation between the (M-O) binding energy and the sensing properties was verified.
Growth and Properties of Ytterbium Doped KY(WO4)2 Nanocomposites
Authors: Borowiec M.T. , Deptuła A. , Łojkowski Witold , Gierlotka Stanislaw , Dyakonov V.P. , Łada Wiesława , Olczak T. , Wawszczak D. , Aleshkevych P. , Domuchowski W. , Zayarnyuk T. , Barański M. , Czech M. , Szymczak H.
Published: March 2009

Nanocomposites (nanocrystals) of KY(WO4)2 and KY(WO4)2+1% mol Yb were synthesized using a Complex Sol-Gel Process (CSGP). A chemical treatment with concentrated nitric acid and hydrogen peroxide was used to reduce the decarbonisation temperature. The expected monoclinic phase C2/c of the KYW of the nanocomposite powder was confirmed using XDR. From the X-ray diffraction measurements, the unit cell parameters and the size of nanoparticles was determined. Electron spin resonance studies in the X band were carried out on KYW and KYW:Yb nanocrystals. The sintered samples were made with using the high pressure technique at temperatures up to 600oC. In addition chemical analysis, X-ray diffraction measurements and ESR investigations were carried out on the sintered samples.
The Effects of Oxidized and Oxide-Free Boron on the Mg-B-H Nanohydrides Transformation in the Nearly Nanosized Powders
Authors: Varin R.A. , Chiu Ch. , Wronski Zbigniew S. , Calka Andrzej
Published: March 2009

In this work oxidized and oxide-free amorphous boron (a-B) powder and elemental Mg
were used in an attempt to directly synthesize the Mg(BH4)2 complex hydride by controlled reactive
mechanical alloying (CRMA) under hydrogen in a magneto-mill up to 200h. The particle size was
refined to the 100-200nm range. Nanocrystalline MgH2 (~6nm crystallite size) was formed within
the particles when an oxidized a-B is used. In contrast, a mixture of MgB2 and an amorphous
hydride MgHx was formed when an oxide-free a-B was used. Differential scanning calorimetry
(DSC) test up to 500°C produced a single endothermic heat event at 357.7°C due to hydrogen
desorption. In addition, desorption conducted in a Sieverts-type apparatus revealed ~1.4wt.% of
hydrogen release. The X-ray diffraction pattern after DSC test of the 200h milled sample made with
oxide-free boron showed the presence of MgB2.
Particle Size Distribution of ZrO2:Pr3+ – Influences of pH, High Power Ultrasound, Surfactant and Dopant Quantity
Authors: Möller Stephanie , Fidelus Janusz D. , Łojkowski Witold
Published: March 2009

The aim of the work was to examine the influence of pH, high power ultrasound,
surfactant and dopant quantity on the particle size distribution of ZrO2:Pr3+, with praseodymium
content varying between 0.05 and 10 %. The nanopowders were obtained via a hydrothermal
microwave driven process. To establish if the dopant was located on the surface of the zirconia
nanoparticles, the particle size distribution, as a function of pH, was measured to obtain an estimate
of the isoelectric point of the samples. All results indicated that the dopant was concentrated on the
surface: the measurements of the particle size distribution show that the pH corresponding to
maximum average particle size changes towards higher values when the Pr content increases.
Measurements of the particle size distribution dependency on the application of high power
ultrasound and the addition of the sodium dodecyl sulphate surfactant show that, under certain
conditions, there is a better stabilisation of the nanopowders in a dispersion and undesirable
agglomeration is hindered.
Analysis of Oxygen Segregation at Metal-Oxide Interfaces Using a New Lattice Monte Carlo Method
Authors: Belova Irina V. , Murch Graeme E. , Muthubandara Nilindu , Öchsner Andreas
Published: March 2009

The presence of atomic oxygen at internal metal-ceramic oxide interfaces significantly affects the physical properties of the interfaces which in turn affects the bulk properties of the material. We address this problem for the case of a constant source of oxygen at the surface and periodic arrangements of ceramic oxide (MgO) inclusions embedded in a metal (Ag) matrix. We simulate the time-dependence of the oxygen concentration into the material using a newly developed lattice Monte Carlo method that takes into account a constant source of diffusant.
Crytalline Precipitates in Silver Ion Conducting Materials
Authors: Wiśniewski Z. , Górski Ludwik , Nowiński J.L. , Wiśniewski R.
Published: March 2009

Structure and pressure induced volume change of silver ion superionic conductors were
investigated. Research concentrated on three groups of materials: xAgI-(1-x)(Ag2O-B2O3),
xAgI-(1-x)(Ag2O-P2O5) and xAgI-(1-x)(Ag2O-MoO3). Strong correlation between structure
and compressibility was found.
Devitrification and Nano-Crystalline/Amorphous Composite Formation in Ni64Cu9Fe8P19 Glassy Alloy at Elevated Temperatures
Authors: Ziewiec Krzysztof , Lelątko Józef , Pączkowski Paweł , Bryła Krzysztof
Published: March 2009

The Ni64Cu9Fe8P19 alloy was prepared using 99.95 wt % Ni, 99.95 wt % Cu, 99.95 wt %
Fe and Ni-P master alloy. The melt spun ribbon in as-cast state was characterized using of
transmission electron microscope (TEM) and X-ray diffraction (XRD). The amorphous alloy was
subjected to DTA and resistivity measurement in order to determine the thermal stability at elevated
temperatures. The melt spun ribbon had a negative TCR=-2.23·10-6K-1 that is stable up to the
Tg-dep=511K. At higher temperature Tg-int=560K the relative resistance starts to decrease and
between 573K and 591K the rate of the decrease reaches TRC=-480.096 K-1. After the heating
cycle to 633K, during cooling the alloy has a positive TRC=6.03·105 K-1. DTA curve presents the
three exothermal stages with the onsets and peak values at I: Tx1=564K and T1=611K, II: Tx2=655K
and T2=662K, III: Tx3=697K and T3=715K, respectively. The melting stage can be characterized by
endothermic peak with Tm=1149K and Tl=1174K. On the base of the measurements the amorphous
alloy was heated to the temperatures where subsequent transformations occurred. TEM study
delivered information about formation of the M3P type tetragonal phosphide (a=9.040Å, c=4.462Å)
nanocrystals within the amorphous matrix after the first stage of crystallization.
Structural Studies of Metallic Powders Fe-Al-X (X= Fe, Ni, Cu, Cr) Type Obtained by the Self-Decomposition Method and Electro-Magneto-Mechanical Grinding
Authors: Hanc Artur , Frąckowiak J.E. , Binczyk F. , Dercz Grzegorz , Pająk Lucjan , Tomczyk A.
Published: March 2009

The Fe-Al-X and Fe-Al-Ni-X (X = Fe,Ni,Cu,Cr) metallic powders obtained by the selfdecomposition
method and next intensive grinding in an electro-magneto-mechanical mill
were examined by X-ray powder diffraction (XRD). Morphology of powders was determined
by scanning electron microscopy (SEM) whereas energy dispersive spectroscopy (EDS) was
applied to identify the composition of phases. The FeAlX and FeAlNiX phases both of B2
type structure were found besides small amounts of Al(OH)3 and rest of metallic additions.
Nanoindentation of GaAs (001) Surface. A Molecular Dynamics Study
Authors: Chrobak Dariusz , Chrobak Artur , Nowak Roman
Published: March 2009

The present paper reports molecular dynamics study of the elastic deformation of zinc- blende GaAs crystal by spherical diamond indenter acting on the (001) plane. The atomic displacements under field of elastic deformation result in generation of characteristic atomic structure with arms located along <110> directions. The phase transformation from zinc-blende to rock-salt GaAs structure was recognized in thin volume under indenter.
Polycrystalline Compounds Cd1-xNixCr2Se4 Obtained by Ceramic Technology
Authors: Jendrzejewska Izabela , Goryczka Tomasz , Kaczmarek Karolina , Maciążek Ewa
Published: March 2009

The polycrystalline compounds of the general formula Cd1-xNixCr2Se4 have been prepared
by the ceramic method in closed silica tubes using CdSe, NiSe and Cr2Se3. The phase composition
and structural data have been determined by X-ray diffraction. The observed symmetry is cubic,
space group Fd 3m . Apart from spinel phases, other phases were observed: CdSe, NiSe2 and
Cr5.6Se8. Depending on amount of nickel, nickel ions can occupy tetrahedral and octahedral sites.
SAXS Study of Selected Cationic Surfactant Influence on the DSPC-Based Model Phospholipid System
Authors: Kozak Maciej , Domka Ludwik , Jurga Stefan
Published: March 2009

The phase behaviour of lipid bilayer systems prepared with 1,2-distearoyl-sn-glycero-3- phosphocholine (DSPC) with dodecyldimethyl(benzyloxymethyl)ammonium chloride (BzMDDAC) (at concentrations 0.1, 1 and 5%) has been studied by small angle X-ray scattering and differential scanning calorimetry. The SAXS and DSC results of the hydrated 10% DSPC revealed one typical phase transition corresponding to melting of the hydrocarbon chains at 55 °C. In the system of 10% DSPC - 0.1 % BzMDDAC the main transition was somewhat shifted towards lower temperatures, while at 1% concentration of BzMDDAC in the mixture, the lamellar phase disappeared, as evidenced by SAXS and DSC. The increase in BzMDDAC concentration to 5% in the mixture with 10% DSPC resulted in formation of a new lamellar phase.
The Structure Studies on Si-N Thin Layers
Authors: Karolus Małgorzata , Łągiewka Eugeniusz
Published: March 2009

In structure studies performed using the Grazing Incident X-ray Diffraction Geometry
(GIXD) for different incident angles it was indicated that the Si-N layers are non-homogenous and
their structure depends on the penetration depth. The layers close to substrate (α = 2, 1°) show the
presence of the Si3N4, SiO2, SiO2, SiC phases and an amorphous Si-N phase as well. The layers near
the surface (α = 0.5; 0.25; 0.15°) are poorer in Si-N phases. There are only observed the presence of
the Si3N4 and SiO2 phases. The obtained results confirm the non-homogenity of layers.
The Reflectometry Studies on SiC and SiN Thin Layers
Authors: Karolus Małgorzata , Bierska-Piech Bożena , Łągiewka Eugeniusz
Published: March 2009

The X-ray reflectivity measurements were used for the analyses of the SiC and SiN thin
layers. Density, roughness and the thickness were determined for searching materials. The
calculations and simulations were carried out using the WinGixa software. The obtained results
show that the studied layers are non-homogenous and there are consist of “sub-layers” rich in Si-C,
Si-N, SI-O phases. Moreover, the presence of the main amorphous phase was observed in all
searching samples.
Application of Energy Dispersive X-Ray Diffraction for the Efficient Investigation of Internal Stresses in Thin Films
Authors: Zschenderlein Uwe , Kämpfe B. , Schultrich Bernd , Fritsche Gudrun
Published: March 2009

Internal stresses are very important for the performance of protective hard coatings. Tensile stresses
favour the formation and propagation of cracks, inducing fracture and corrosion. Medium
compressive stresses hinder fatigue. But high compressive stresses, typically for hard coatings
produced by PVD (physical vapour deposition) processes, support delamination in order to relax the
stored elastic energy. However notwithstanding its relevance, the internal stresses are only seldom
used for the optimisation and quality control of hard coatings in industry. This unsatisfying situation
is caused by the deficit in efficient measuring methods. The results of thin sheets, where the stresses
can be simply measured by their curvature, are not necessarily representative for the coating of
thicker parts. The conventional XRD (X-ray Diffraction), based on angle-dispersive evaluation
needs expensive devices and is rather time consuming. The energy-dispersive technique opens new
possibilities. It is based on polychromatic radiation. The interference of the lattice plane reflections
corresponding to the Bragg-equation is investigated by the diffraction intensity of the different
wavelength (or photon energies), not by varying the Bragg-angle as in conventional XRD. Hence,
the whole diffraction pattern can be obtained in one shoot without the use of any goniometer. This
allows the construction of small and compact measuring devices and the reduction of measuring
time to a few minutes. The capability of the ED-XRD (Energy Dispersive X-ray Diffraction) is
demonstrated for titanium nitride and chromium nitride films deposited by cathodic vacuum arc
with varying parameters. Comparisons were made with the much more time-consuming AD-XRD
(Angle Dispersive X-ray Diffraction) for residual stress analysis. The results of both methods are in
good agreement.
The Deformation Mechanisms of TWIP Steels (Fe-Mn-C) Viewed by X-Ray Diffraction
Authors: Collet J.L. , Bley Françoise , Deschamps Alexis , de Monestrol H. , Berar Jean François , Scott Colin
Published: March 2009

Fully austenitic steels of the Fe-Mn-C system can show extensive deformation twinning (TWIP effect). The deformed microstructure of such steels has been analysed using X-ray diffraction at the European Synchrotron Radiation Facility (ESRF). The experimental diffractograms, recorded using a 2D CCD camera, are analysed in terms of Bragg peak profiles (broadening and asymmetry) and position (shift from the reference [undeformed state] position) leading to an estimation of dislocation and stacking faults densities.
High-Pressure Energy Dispersive X-Ray Diffraction Investigation of Lithium-Manganese Spinel
Authors: Piszora Paweł
Published: March 2009

The formation of the tetragonal high-pressure structure, attributed to the Jahn-Teller distortion, was proved. The c/a axial ratio shows an increasing trend towards a stronger tetragonal distortion at high pressure. Rietveld refinement after the pressure relaxation demonstrates the presence of tetragonal artefacts of the high-pressure structure only for the LiMn2O4 sample compressed in hexagonal boron nitride (h-BN), whereas the sample compressed in silicone reveals the pure cubic phase. Confrontation with the result of the first angle-dispersive diamond-anvil-cell experiment is presented.
Applications of High-Resolution Powder X-Ray Diffraction
Authors: Fitch Andrew N.
Published: March 2009

The highly-collimated, intense X-rays produced by a synchrotron radiation source can be harnessed to build high-resolution powder diffraction instruments with a wide variety of applications. The general advantages of using synchrotron radiation for powder diffraction are discussed and illustrated with reference to the structural characterisation of crystalline materials, atomic PDF analysis, in-situ and high-throughput studies where the structure is evolving between successive scans, and the measurement of residual strain in engineering components.
Crystallization of CoSi2-Si Eutectic Composites
Authors: Gurdziel Wojciech , Wokulski Zygmunt , Szostek Krzysztof , Krawczyk Jacek , Stępniewski Paweł
Published: March 2009

The subject of the study is the composite material of CoSi2-Si eutectic composition. The influence
of crystallization speed on microstructure was examined. The ingots were obtained using Bridgman
method. Three different pulling down speeds of crucibles with melted charges were applied. The
prepared samples were subjected to metallographic, X-ray, TEM techniques and mechanical
examinations in order to characterize the properties of the studied composite material. It was shown
that the favourable crucible pulling down speed to obtain CoSi2-Si fibrous eutectic microstructure
was 3mm/h.
Co-Germanide Schottky Contacts on Ge
Authors: Lajaunie Luc , David Marie-Laure , Opsomer K. , Simoen Eddy , Claeys Cor , Barbot Jean François
Published: March 2009

In this study, Co germanide Schottky barrier diodes on n-Ge (100) substrate were
fabricated by sputtering metal Co on Ge, followed by annealing in vacuum at 700°C. The influence
of annealing time was investigated on both the electrical properties of Co germanide Schottky
barrier diodes and on the phase formation on n-Ge (100) substrate. With increasing annealing times
growing or transformation of germanide entities occurs leading to reduction of the trap
concentration and therefore the leakage current.
Internal Dissolution of Buried Oxide in SOI Wafers
Authors: Kononchuk Oleg , Boedt Francois , Allibert Frederic
Published: March 2009

High temperature anneal of SOI wafers in oxygen-free atmosphere results in internal
buried oxide dissolution and top Si layer etching. Dissolution rate is determined by interstitial
oxygen diffusion through the top Si layer and evaporation from the top Si surface in the form of
SiO. It has been observed that kinetics of the process follows linear-parabolic law. Simple
thermodynamic model is proposed, which explains observed dependences on temperature and top Si
layer thickness.
SiGe Heterostructures-on-Insulator Produced by Ge+-Ion Implantation and Subsequent Hydrogen Transfer
Authors: Tyschenko Ida E. , Cherkov A.G. , Voelskow M. , Popov V.P.
Published: March 2009

The properties of germanium implanted into the SiO2 layers in the vicinity of the bonding
interface of silicon-on-insulator (SOI) structures are studied. It is shown that no germanium
nanocrystals are formed in the buried SiO2 layer of the SOI structure as a result of annealing at the
temperature of 1100° C. The implanted Ge atoms segregate at the Si/SiO2 bonding interface. In this
case, Ge atoms are found at sites that are coherent with the lattice of the top silicon layer. It is found
that the slope of the drain–gate characteristics of the back metal-oxide-semiconductor (MOS)
transistors, prepared in the Ge+ ion implanted structures, increases. This effect is attributed to the
grown hole mobility due to the contribution of an intermediate germanium layer formed at the Si/SiO2
interface.
Impact of NiSi2 Precipitates Electronic Structure on the Minority Carrier Lifetime in n-and p-Type Silicon
Authors: Trushin M.V. , Vyvenko O.F. , Seibt Michael
Published: March 2009

Minority carrier diffusion lengths were measured for the set of n- and p-type silicon
samples with NiSi2 precipitates of different electronic structure. We found that the type of
precipitate electronic states in the upper part of band gap had no influence on the recombination
activity of NiSi2 precipitates. Minority carrier diffusion length L was found to be related to the
precipitate density N and L ~ 2 × N -1/3 for n-type Si samples and L ~ 1 × N -1/3 for p-Si samples.
Hydrogenation of the p-type Si sample with nanoscale nickel silicide precipitates resulted in an
increase of the L value up to a factor of 3, while in n-Si L remained practicaly the same. The only
hole emission in the samples of both conductivity types was detected in MCTS measurements and
the cross section for the hole capture with the electronic states of the precipitaes was estimated to be
as large as 10-11 cm-2.
SEM Investigation of Surface Defects Arising at the Formation of a Buried Nitrogen-Containing Layer in Silicon
Authors: Frantskevich A.V. , Saad Anis M. , Fedotov A.K. , Rau E.I. , Mazanik A.V. , Frantskevich N.V.
Published: March 2009

The main goal of this work is to demonstrate the correlation between the density and type
of surface defects arising during the formation of a buried nitrogen-containing layer in Si wafers,
and the number of buried defects formed by different dose hydrogen preimplantation.
Standard commercial 12 ⋅cm boron-doped and 4.5 ⋅cm phosphorous-doped Cz Si wafers
were subjected to hydrogen ion implantation at room temperature with the energy 100 keV and
doses 1⋅1015 - 4⋅1016 at/cm2. Then nitrogen was introduced into silicon from a DC plasma source at
a temperature of 300 oС. Finally, all samples were subjected to 2 h vacuum annealing at 900 oС.
The experiments have shown that the density and type of the surface defects depend
significantly on the dose of hydrogen implantation, parameters of N+-plasma treatment, and
conductivity type of silicon. Optimization of the above-mentioned parameters makes it possible to
create the substrates containing a buried dielectric SixNy layer and having a practically defect-free
surface.