bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Electromagnetic Properties of Ca2MTeO6 (M = Mn, Co, Mg)
Authors: Shan Yue Jin , Kanai Yoko , Tezuka Keitaro , Imoto Hideo
Published: March 2009

Ordered perovskite-type oxides, Ca2MTeO6 (M = Mn, Co, Mg), were synthesized by a
solid-state reaction method. All of samples belonged to space group P21/n and were insulators at
room temperature. However, their electronic conductivities tended large gradually with a rise of
temperature. Ca2MnTeO6 and Ca2CoTeO6 showed anti-ferromagnetism, and their Neel temperatures
were 10 K and 7 K, respectively. The effective magnetic moment of manganese ion was 5.8 μB while
its valence was bivalence in Ca2MnTeO6.
Synthesis of Cr-Doped Sphene Ceramic Pigments by Spray Drying
Authors: Stoyanova T. , Matteucci F. , Costa Anna L. , Dondi M. , Carda F.J.
Published: March 2009

Ceramic pigments with Cr-doped sphene structure (CaSn1-xCrxSiO5, CaTi1-xCrxSiO5)
were synthesized by both spray drying an aqueous solution of precursor salts plus further calcining
the resulting powders and conventional ceramic method. The thermal evolution of products was
studied by X-Ray Powder Diffraction (XRPD). The powder morphology and chemical composition
were analyzed by SEM-EDX. The color efficiency of pigments was evaluated by colorimetric
analysis (CIELab system). Results showed that the spray drying process decreased the maximum
firing temperature and increased the color efficiency of Cr-doped sphene pigments therefore
enhancing a higher reactivity of powders compared with the solid state process.
SiC Powder for Casting from Aqueous Suspension
Authors: Stobierski Ludosław , Lis Jerzy , Gubernat Agnieszka
Published: March 2009

The activation of silicon carbide by boron and carbon is required to obtain dense monophase
sintered body from SiC powder. The presence of carbon renders casting from aqueous
suspension impossible. The SiC powders with boron and extra carbon were prepared by combustion
method (SHS), where carbon was bound to SiC particles in a stable way. The experiments showed
that this powder could be used for processing by casting of aqueous suspension. Finally nearly
dense polycrystals were obtained by pressureless sintering.
Bismuth Zinc Niobate (Bi1.5ZnNb1.5O7) Nanopowder Derived from High Energy Mechanical Activation
Authors: Zanetti S.M. , Pereira M.G.S. , Nono Maria do Carmo de Andrade
Published: March 2009

Bismuth zinc niobate belongs to the pyrochlore-based microwave dielectrics, with high ε
and low dielectric losses. This research reports the results obtained on the bismuth zinc niobate
pyrochlore (Bi1.5ZnNb1.5O7 - α-BZN) synthesis by a mechanochemically assisted method. The
mechanochemical activation allows reducing the particle size of the initial products, leading to an
increase in the specific surface, improving in most cases its reactivity. The effects of changing the
milling parameters (ball size, speed, and length of the mechanical treatment) are discussed. The
obtained powders were characterized by X-ray diffraction, thermal analysis, optical spectroscopy
and scanning electron microscopy. The activated powder was annealed at temperatures ranging
from 500 to 800oC. A well crystallized cubic pyrochlore phase can be obtained at 600 oC, which
represents a significant decrease in temperature, if compared with the conventional ceramic
synthesis method. The mechanically activated powders exhibit a particle size of around 160 nm,
which increases with further thermal treatment.
Dispersion Properties of Polymer Encapsulated TiO2 Nano-Powders in Low Dielectric Solvents
Authors: Kim J.H. , Lee Nam Hee , Oh Hyo Jin , Yoon Cho Rong , Kim Wheung Whoe , Song Jae Sung , Jeon C.J. , Kim Sun Jae
Published: March 2009

An electrophoretic solution using TiO2 nano particles is the most promising candidate in
electronic paper industry because it offers various advantages such as ink-on-paper appearance, good
contrast ratio, wide viewing angle, image stability in the off-state and extremely low power
consumption. To prepare an electrophoretic solution of TiO2 nano particles with low apparent gravity
for electronic paper, TiO2 powders were mixed with polyethylene powders using high energy
planetary-mill in cyclohexane with low dielectric constant and transparency. The zeta-potential value
of raw TiO2 particles in cyclohexane was measured about -80mV but that of polyethylene-coated
TiO2 particles by milling was measured over -110mV, with showing good dispersibility by surfactant
attached to them. Thus it was possible to control surface charge on the TiO2 particle by using
optimum amount of surfactant after polyethylene coating on them for enhancement of dispersion
stability.
The Use of Capability Indices in Process Evaluation of Ceramic Materials
Authors: Papargyri S. , Tsipas D.N. , Botis A. , Papargyris A.
Published: March 2009

In order to manufacture products of acceptable quality within predetermined specification
limits, an evaluation of the manufacturing process through the use of capability indices is necessary.
Capability indices are used in order to evaluate a process and to monitor the product characteristics
and the results of quality improvement cycles. The three point bending strength
of kaolin ceramic specimens produced by two different production processes (slip casting and
hydroplastic extrusion) were investigated. It was found that under statistical control and normal
distribution of strength values, the process capability indices Cp, Cpk, regardless of any
disadvantages and the fact that they have limitations, can be combined with other techniques in the
field of statistical process control and become valuable tools in process evaluation of ceramic
products.
Monolithic and Cellular Sintered Glass-Ceramics from Wastes
Authors: Bernardo Enrico , Scarinci Giovanni , Hreglich S.
Published: March 2009

Several kinds of wastes have been converted into glasses, successively powdered and
sintered with simultaneous crystallisation. The employed “sinter-crystallisation” process was useful
to obtain glass-ceramics with particular crystal phases (sometimes un-accessible from traditional
nucleation/crystal growth treatments, like feldspar crystals). Conventional pressing of fine glass
powders led to monoliths, after sintering, with remarkable mechanical properties (for example
bending strength exceeding 100 MPa), useful for tile applications; replication processes, by
employing sacrificial polymeric materials, after the same thermal treatment employed for the
monoliths, led to open-celled glass-ceramic foams, useful for filtering applications. The enhanced
specific surface due to porosity was found to have a positive effect on crystallisation.
Bio-Inspired Processing of Ceramic Materials
Authors: Bill Joachim
Published: March 2009

Ceramic processing without firing, sintering and expensive equipment represents a
growing research field within materials science. With respect to the search of new synthesis
pathways living nature provides paradigms for procedures that occur at ambient conditions and by
apparently simple means. In this connection, biomineralization yields highly complex
organic/inorganic structures, e. g. within nacre or bones. In general, the formation of these
biominerals involves organic molecules that act as templates during the mineralization of inorganic
phases.
Bio-inspired ceramic synthesis aims to imitate such principles by technical means. Accordingly,
these routes consider the template-induced formation and the structural design of ceramics from
solutions of suitable metal salts. This paper describes such routes by means of the preparation of
ceramics like titania, vanadia, and zinc oxide. The influence of (bio)organic molecules (e. g.
polyelectrolytes, self-assembled monolayers, amino acids, peptides and proteins) on the micro- and
nanostructure formation and on the evolution of the morphology of these solids will be discussed.
Furthermore, mechanical as well as functional properties of the obtained architectures are treated.
Soft Solution Synthesis and Characterization of Zinc Oxide Films with Nano-Rods and Nano-Screws Superstructures
Authors: Yin Shu , Li Rui Xing , Sato Tsugio
Published: March 2009

Novel superstructures of zinc oxide thin film with nano-rods and nano-screws were
prepared via soft solution route without any polymer additives. The thin film of ZnO could be
produced directly on the substrates. The yield of nano-rod and/or nano-screw was almost 100%.
Small amount of nano-disk superstructure was also obtained. The superstructures of the film changed
depending on the kind of treatment organic solvent such as methanol, butanol, i-propanol, hexane, etc.
Monodispersed or symbiotic/multipod ZnO nanorods with hexagonal cross section or screw
microstructure were successfully prepared.
Free Form Fabrication of 3D-Ceramic Parts with InkJet-Printing
Authors: Kaufmann Ulrike , Harrysson Urban , Johander Per , Bauer Werner
Published: March 2009

A rapid manufacturing method for fabrication of 3D ceramic parts will be presented. The structural information is printed by ink jet in powder layers of 80 µm thickness. Different granulated powders can be used, such as zirconia and alumina if they show good flow ability. After printing the structures a heating process takes place. After these the parts can be picked out from the powder bed. The manufactured parts can be impregnated with epoxy. Another option is the infiltration with ceramic slurries and glass with sintering to higher density. The sintering process has been studied and the shrinkage and material properties evaluated. The interrelationship between the raw material qualities, infiltration media and the sinter parameters as well as the material-specific properties such as density and stability will be presented. The manufacturing method is used for fabrication of moulds and cores for casting processes. Otherwise the process can be used for fast fabrication of models and prototypes. The possibilities to use these methods for implant manufacturing will be shown. A cost analysis has been performed comparing direct manufacturing of small batches of components to mould injection processes.
Nanoceramics-Biomolecular Conjugates for Gene and Drug Delivery
Authors: Choy Jin-Ho , Oh Jae Min , Choi Soo Jin
Published: March 2009

We were quite successful in demonstrating that two-dimensional inorganic compounds
like anionic and cationic clays can be used as gene or drug delivery carriers, those which are
completely different from conventional ones such as viral-based, naked, and cationic liposomes,
those which are limited in certain cases of applications due to their toxicity, immunogenecity, poor
integration, and etc. Since LDHs with positive layer charge have an anion exchange capacity,
functional biomolecules with a negative charge can be intercalated into hydroxide layers of LDH by a
simple ion-exchange reaction to form a bio-LDH nanohybrid. On the contrary, clays can uptake
biofuctional molecules or drugs with positive charge in the interlayer space by cation exchange
reaction. The possible roles of inorganic lattice as the gene and drug delivery carrier will be shown by
demonstrating the cellular uptake experiments of FITC-LDH, with laser scanning confocal
fluorescence microscopy as well as of radioactive isotope-labeled ATP-LDH hybrid. As the typical
examples for gene and drug delivery systems, As-myc-LDH, MTX-LDH, and Itraconazol-clay
nanohybrids will be demonstrated in detail.
Modelling of the Generation of Residual Stresses of Thermal Origin in Ceramic Materials
Authors: Cantavella V. , Mezquita A. , Moreno Arnaldo , Silva G. , Barberá J.
Published: March 2009

During the cooling of ceramic materials stresses arise that cause flows of material. These
flows lead to residual stresses in the materials at the kiln exit. Laboratory tests were carried out
using a composition based on white-firing clays, which was fired according to cycles with different
cooling rates. Residual stresses were measured using the layer removal method. The internal
temperature profile during industrial cooling and the stress generation process were simulated. The
results of the simulation fit with great accuracy the experimentally measured residual stress values.
Microwave Processing of Ceramics
Authors: Lloyd Isabel K. , Carmel Yuval , Wilson Jr. Otto C. , Xu Geng Fu
Published: March 2009

Microwave (MW) processing is advantageous for processing ceramics with tailored
microstructures. Its combination of volumetric heating, a wide range of controlled heating
rates, atmosphere control and the ability to reach very high temperatures allows processing
of 'difficult' materials like high thermal conductivity AlN and AlN composites and
microstructure control in more readily sintered ceramics such as ZnO. MW sintering
promotes development of thermal conductivity in AlN (225 W/mK) and its composites (up
to 150W/mK inAlN-TiB2 and up to 129 W/mK in AlN-SiC when solid solution is avoided).
In ZnO, heating rate controls sintered grain size. Increasing the heating rate from 5°C/min.
to 4900°C decreases grain size from ~10 μm (comparable to conventional sintering of the
same powder) to nearly the starting particle size (~ 1μm). Microstructural uniformity
increases with sintering rate since ultra-rapid MW sintering minimizes the development of
thermal gradients due to heat loss.
High-Pressure Synthesis of High-Purity and High-Performance Diamond and cBN Ceramics
Authors: Sumiya Hitoshi
Published: March 2009

High-purity, single-phase polycrystalline diamond and cBN have been successfully
synthesized by direct conversion sintering from graphite and hBN, respectively, under static high
pressure and high temperature. The high-purity polycrystalline diamond synthesized directly from
graphite at ≧15 GPa and 2300-2500 °C has a mixed texture of a homogeneous fine structure (grain
size : 10-30 nm, formed in a diffusion process) and a lamellar structure (formed in a martensitic
process). The polycrystalline diamond has very high hardness equivalent to or even higher than that
of diamond crystal. The high-purity polycrystalline cBN synthesized from high-purity hBN at 7.7
GPa and 2300 °C consists of homogeneous fine-grained particles (<0.5 μm, formed in a diffusion
process). The hardness of the fine-grained high-purity polycrystalline cBN is obviously higher than
that of single-crystal cBN. The fine microstructure features without any secondary phases and
extremely high hardness of the nano-polycrystalline diamond and the fine-grained polycrystalline
cBN are promising for applications in next-generation high-precision and high-efficiency cutting
tools.
Simulation of the Thermoelastic Properties of Sintered Ceramics
Authors: Iuga Maria , Raether Friedrich
Published: March 2009

Many ceramic materials are composed of various phases, which can differ in their
individual thermal, elastic or electrical properties by orders of magnitude. The microstructural
arrangement of the phases controls important material properties of the composite. To simulate
these macroscopic material properties from the material properties of the constituting phases, a 3-D
FEM model is used. The key for an adequate description of real materials is the accurate threedimensional
modeling of their microstructure. Basic morphological parameters of many ceramics
are reflected by a modified Voronoi model, e.g.: the volume fractions, grain size ratios and
contiguity of the phases. By automatically generating thousands of test structures and comparing
them to quantitative data derived from image analysis of scanning electron micrographs, structures
are selected which closely fit to the microstructure of experimental samples. The model
considerations are illustrated on two types of bi-continuous ceramic materials, a porous alumina
(Al2O3) and a dense zirconia toughened alumina (ZTA) ceramic. Using different volume fractions
of the phases, Voronoi type microstructures and truncated sphere models are exemplified. For these
two ceramic systems, elastic moduli and thermal conductivity are calculated and compared to
experimental data of samples of the respective microstructure.
Hot Explosive Consolidation of WC-AlNi Composites
Authors: Japaridze Levan , Peikrishvili Akaki B. , Kecskes Laszlo J. , Chagelishvili Elguja , Klotz Bradley R. , Pritchett Justin E. , Godibadze Bagrat
Published: March 2009

WC + Ni-clad Al, Ni(Al), powder mixtures were formed into cylindrical rods or tubes using a hot
explosive consolidation (HEC) process. During HEC, the Ni(Al) precursor, in the WC + Ni(Al)
mixture, was found to react to form a WC-AlNi composite structure. The composite consisted of WC
particles dispersed in a matrix of Al-Ni intermetallic phases. The consolidation temperature was
varied from room temperature to 800°C; the shock loading intensity was as high as 10 GPa.
The investigation showed that the combination of high temperatures and explosive
compression was beneficial to the consolidation of the WC-AlNi composites, resulting in
high densities, good integrity, and the formation of transient layer between the sample and the
steel container’s wall. The structure and property of the samples obtained, and the formation
of the transient layer depended on the shock loading conditions and the consolidation
temperature. Features of the consolidated WC-AlNi samples as a function of the loading
conditions (experimental set-up, loading intensity, and preheating temperature) are discussed.
Conventional and SPS Sintering of a Nanocrystalline Alumina: A Comparative Study
Authors: Palmero Paola , Locci Antonio Mario , Tulliani Jean Marc , Orrù Roberto , Cao Giacomo , Montanaro Laura
Published: March 2009

In this paper, five powdered samples, containing different amounts of nanosized α-alumina,
were obtained by controlled thermal pre-treatments of a transition alumina, and then densified by
both free-sintering in air at 1500°C for 3 h and by Spark Plasma Sintering in the temperature range
1150°C - 1400°C with different soaking times at the maximum temperature. A comparative study of
the influence of the phase composition in the starting alumina powders on both sintering behavior
and microstructural features of the densified bodies is presented, showing a relevant influence of
powder thermal pre-treatment on the SPS process, in a strict analogy to natural sintering.
Synthesis and Thermolelectric Properties of Bi2Te3-GeTe Pseudo Binary System
Authors: Kohri Hitoshi , Shiota Ichiro , Kato Masahiko , Ohsugi Isao J. , Goto Takashi
Published: March 2009

Bi2Te3 is the best compound for thermoelectric materials around the room temperature. If
the temperature range is shifted to higher side, it is useful to obtain electrical energy from waste heat
source which is abundant at the temperature around 500 K. In this experiment, Bi2Te3-GeTe pseudo
binary compounds were investigated to shift the temperature range. The lattice thermal conductivity
was remarkably decreased at 50 or 75 mol%GeTe by synergy effect of solid solution and grain
boundaries. The peak temperature of figure of merit Z for Bi2Te3-GeTe pseudo binary compounds
was higher than Bi2Te3.
Carbon-Coated TiO2 - Hybridization between Photoactivity and Adsorptivity
Authors: Toyoda Masahiro , Tryba Beata , Koujin Fumi , Tsumura Tomoki , Inagaki Michio
Published: March 2009

Carbon-coated TiO2 photocatalysts were prepared by a simple heat treatment of the powder mixtures
of anatase-type TiO2 with PVA at a temperature of 700 and 900 oC in a N2 atomosphere. Diffuse optical
reflectance spectra for carbon-coated TiO2 showed the absorption edge for anatase structure clearly, overlapping
with absorption due to coated carbon over whole range of wavelegth. These carbon-coated TiO2 photocatalysts
had relatively high apparent BET surface area, from 50 to 170 m2/g, which suggested the formation of porous
carbon layers, and showed relatively high adsorption of various pollutants, methylene blue (MB), reactive black
(RB-5), phenol (Ph) and iminoctadine triacetate (IT), in water. Photocatalytic activity of carbon-coated TiO2 thus
prepared was evaluated through the determination of the rate constant for the decomposition of different
pollutants in water. Rate constant values were strongly depend on the pollutants, but their dependence on the
crystallinity of TiO2 phase. The relations between adsorptivity and rate constant for four pollutants looked
similar with each other, and the pollutants adsorbed in the larger amount was decomposed with the higher rate.
Adsorptivity of carbon-coated TiO2 photocatlysts was determined and discussed on the relations to BET surface
area, amount of carbon coated and also rate constant k for the decomposition of MB, RB5, Ph and IT.
Adsorptivity of carbon-coated catalysts depends strongly on the adsorbate (pollutant) but also on the surface
nature of carbon layer on TiO2 particles. The relations between adsorptivity and rate constant k for four
pollutants looked similar, suggesting that the pollutant adsorbed in the larger amount being decomposed with the
higher rate.
Diffusion Rates of51Cr,54Mn and 59Fe in MnCr2O4 and FeCr2O4 Spinels
Authors: Gilewicz-Wolter Jolanta , Żurek Zbigniew , Dudala J , Lis Jerzy , Homa Martah , Wolter Marcin
Published: March 2009

As the result of oxidation of Cr-Mn steels in SO2 the three layer scale is formed. The
intermediate layer of this scale is composed mainly of MnCr2O4 spinel whereas FeCr2O4 spinel is
present in small amount. MnO dominates in the outer layer. The inner, very thin scale layer
contains oxides/sulfides mixture. The aim of this study was to examine self-diffusion processes in
both spinels by multitracer method of diffusion measurements to know which of the transport
processes during oxidation is the smallest one and deciding on the corrosion rate. In diffusion
experiments the radioisotopes 54Mn, 51Cr and 59Fe were used. The serial sectioning method was
applied to simultaneous evaluation of diffusion rates of chromium, manganese and iron in both
spinels at 1073 K and 1173 K under the pressure of 105 Pa in SO2 containing 10 Pa O2. These
spinels were obtained by modified sol-gel method from nitrates. Structures of the spinels were
examined by X-ray spectrometry. It was found, that the diffusion rates of metals are higher in
MnCr2O4 spinel. Moreover the dominant mechanism of manganese transport (the highest one) in
studied samples is the volume diffusion while chromium and iron are transported mainly through
the high diffusivity paths.
Water Diffusion in Silicate Glasses and Melts
Authors: Behrens Harald
Published: March 2009

Knowledge on diffusion of water in glasses and melts is important for glass sciences as
well as for Earth sciences. The ranges of water contents differ widely in both research domains.
Industrial glass contain typically less than 0.1 wt% H2O whereas natural glasses may even contain
up to 10 wt% H2O. Dissolved water strongly modifies physical and chemical properties of the melts
and, hence, water diffusion studies at low water contents often cannot be transferred to high water
contents and vice versa. Pressure effect on water diffusion, on the other hand, is small so that high
pressure data can be applied also at ambient pressure without significant error. At low water
contents the assumption of constant water diffusivity is often justified whereas at high water
contents the H2O diffusivity increases strongly (often linearly or exponentially) with water content.
Combining experimental data over a wide range of water contents allows getting deeper
understanding of the mechanisms of water diffusion and of the effect of dissolved water on melt
structure. In this paper an overview is given on experimental investigations on water diffusivity in
aluminosilicate and silicate systems. Effects of base compositions and water content on water
diffusivities are discussed. New experimental results for water diffusion in soda lime silica glass,
float glass and borosilicate glass are presented.
Ionic Conductivity of Hydrous Silicate Glasses
Authors: Fanara Sara , Behrens Harald , Kappes Regina
Published: March 2009

Hydrous silicate glasses with different compositions (LiAlSi4O10, CaMgSi2O6, CaMgSi2O6 -
CaAl2Si2O8 and (Ca,Ba,Sr)O – SiO2) containing up to 3 wt% H2O were synthesized in platinum
capsules at high temperature and pressures from 100 to 500 MPa in an internally heated gas pressure
vessel. The water content of the glasses was analyzed by Karl-Fischer titration. Using infrared
microspectroscopy the homogeneity of water distribution in the samples was checked and
concentrations of OH- groups and H2O molecules were estimated. Frequency-dependent ionic
conductivity of the glasses was investigated using impedance spectroscopy. It is shown that the proton
conductivity is usually orders of magnitude lower than the partial conductivity of alkalis in silicate
glasses. Proton conductivity in hydrous barium silicate glass was found to be more than one order of
magnitude higher than in an aluminosilicate glass, supporting that the concentration of non-bridging
oxygen is crucial for proton conduction in glasses.
Diffusivity, Solubility and Speciation of Sulphur in Silicate Melts
Authors: Stelling J. , Behrens Harald , Deubener Joachim , Mangold Stefan , Goettlicher Joerg
Published: March 2009

Diffusion and solubility of sulphur have important effects on the degassing of silicate
melts. Both properties are closely related to the structural incorporation of sulphur in the melt.
Depending on the oxygen fugacity, sulphur can be present as sulphide (S2-), sulphite (S4+) or
sulphate (S6+). Sulphates play an important role in the industrial production of glasses especially in
the fining process. The decomposition products of sulphate amass in bubbles which ascend and
homogenize the melt. Structural incorporation of sulphur in glasses is studied by XANES (X-ray
Absorption Near Edge Spectroscopy). Diffusion of sulphur is investigated in simple silicate systems
using the diffusion couple technique. First diffusion profiles were measured in sodium trisilicate
glasses by electron microprobe. The results indicate that sulphur diffusivity in high temperature
melts is close to the Eyring diffusivity calculated from viscosity data.
Effect of Co Doping on the Superconducting Properties of Overdoped (Lu0.8Ca0.2)Ba2Cu3Oz
Authors: Lee Ho Keun
Published: March 2009

The effect of Co-doping and thermal treatments on the superconducting properties of the
heavily overdoped (Lu0.8Ca0.2)Ba2Cu3Oz has been investigated by X-ray diffraction, resistivity and
thermoelectric power measurements. A comparative analysis of the resistivity and thermoelectric
power of the (Lu0.8Ca0.2)Ba2(Cu3-xCox)Oz and the heat-treated Co-free (Lu0.8Ca0.2)Ba2Cu3Oz reveals
that, in the overdoped region, the hole carriers reduced by the Co doping and by the oxygen depletion
play a very similar role in the superconducting properties. As a result, a nearly common inverted
parabolic correlation is observed between Tc and the planar carrier concentration determined from the
room-temperature thermoelectric power measurements.
Scaling of Resistivities in MgB2
Authors: Vašek Petr
Published: March 2009

Longitudinal and transverse voltages have been measured on thin films of MgB2 with different width of superconducting transition range. The study has been performed in zero and nonzero external magnetic fields. The non-zero transverse voltage has been observed in close vicinity of the critical temperature in zero external magnetic field while far enough from Tc this voltage has been zero. In magnetic field it merges into transverse voltage which is an even function with respect to the direction of the field. Usual Hall voltage starts to appear with increasing magnetic field. At the highest field the even voltage disappears and only the Hall voltage is measurable i.e. the transverse even voltage is suppressed with increasing magnetic field and increasing transport current as well. New scaling between transverse and longitudinal resistivities has been observed in the form ρxy~dρxx/dT . This correlation is valid not only in the zero magnetic field but also in nonzero magnetic field where transverse even voltage can be detected. Several models trying to explain observed results are discussed. The most promising seems to be guided motion of the vortices.
Progress of YBCO Coated Conductor in JAPN and Recent Advance of PLD and IBAD Method
Authors: Yamada Yutaka , Izumi Teruo , Shiohara Yuh
Published: March 2009

In the present 5-year national project since 2003, the development of YBCO coated conductors
(CC) has advanced rapidly. The high performance processing group of SRL-ISTEC and Fujikura Ltd.
has been working on the long tape of the PLD-YBCO superconductor on the IBAD-Gd2Zr2O7
buffered substrate tape. Very recently the SRL group achieved the highest value on the product of Ic x
L in the world, 51,940 Am (212 m x 245 A). Fujikura Ltd. also realized the longest buffered substrate
tape of 500m long IBAD tape and obtained a 200 m long coated conductor with Ic value of 88 A. In
the low cost processing group using MOD, CVD and so on, the high Ic value of 525 A was obtained
by SRL using the TFA-MOD method on the IBAD substrate. The 45m long TFA-MOD tape was also
obtained with the Ic value of 155 A by Showa Electric Wire and Cable Company. Similarly 100- 200
m class long tapes were also obtained by the MOCVD (Chubu Power Electric Company) and
PLD-HoBCO processes (Sumitomo Electric Industry Ltd.). Both groups above are further developing
for the final goal of 500 m long tapes with the Ic of 300 A/cm-w at the production rate of 5 m/h.
Furthermore, the feasibility study for the application has started due to the above success of long tape
production. Several kinds of preliminary experiments using long coated conductors are now in
progress for the power applications such as (1) Power Cable, (2) Transformer, (3) Motor and so on.
Fabrication and Evaluation of Ag-Bi2223 Composite Tapes with Interfilamentary Resistive Barriers
Authors: Inada Ryoji , Iwata Yoshitaka , Nakamura Yuichi , Oota Akio , Zhang Ping Xiang
Published: March 2009

We fabricated Ag-sheathed Bi2223 composite tapes with interfilamentary resistive
barriers by using powder-in-tube (PIT) method and evaluated their AC loss characteristics at 77 K.
The mixture of Ca2CuO3 and 30 wt% Bi2212 are used as the barrier material for tape fabrication. The
barrier layers were coated on all surfaces of the hexagonal monocore wires. Then, several pieces of
the coated wires were stacked and inserted into an Ag tube, and the composites were deformed into
tape shape. By introducing the barrier layers between the filaments, the Jc values at 77 K and
self-field are degraded about 15%. The loss measurements under AC parallel transverse magnetic
field were systematically performed, as a function of field amplitude and frequency. The loss
properties in the barrier tape were compared with those in the tape without barriers. The results
indicated that introducing Ca2CuO3 barriers is effective to suppress the electromagnetic coupling
among the filaments and also to reduce the magnetization losses under parallel transverse field. We
also present the fabrication of the barrier tapes on the order of several meters, together with the
uniformity of superconducting properties along a length direction.
Progress of RSFQ High Performance Packet Switch
Authors: Yorozu Shinichi , Hashimoto Yoshihito , Kameda Yoshio , Miyazaki Toshiyuki
Published: March 2009

Internet traffic loads are increasing. Sustaining packet switching throughput of a core node
will be difficult. A major reason for this is power consumption and packaging volume. As long as we
use only current semiconductor technology, the switching capacity will be limited. Rapid single flux
quantum (RSFQ) superconducting technology can overcome such difficulties because of high-speed
operation and low-power consumption characteristics. A superconducting wiring also enables
high-speed inter-chip communication. We report on progress on packet switch circuit
implementation and cryo-cooled packaging for a RSFQ packet switch system. In addition, we discuss
a possible packet switch architecture over 100 Tbps that uses RSFQ technology.
Development of a Superconducting Transformer for Rolling Stock
Authors: Fujimoto Hiroyuki , Hata Hiroshi , Kamijo Hiroki , Nagashima Ken , Ikeda Kazuya , Iwakuma Masataka , Funaki Kazuo , Yamada Hisao , Sanuki Yasutaka , Tomioka Akira , Uwamori Ken Etsu , Yoshida Shigeru
Published: March 2009

Having undertaken studies into a lightweight and highly efficient superconducting transformer for rolling stock, we developed a prototype with a primary winding, four secondary windings and a tertiary winding using Bi-2223 high temperature superconducting wire. Its primary voltage is 25kV, which is widely adopted as the catenary voltage on the world's high-speed lines. We adopted liquid nitrogen cooling, the weight being 1.71t excluding the refrigerator. The maximum output available to maintain superconductivity is 3.5MVA. We also introduce railways in Japan.
Prospects of Application of Superconductivity in Underground Transmission Lines and Levitating Trains
Authors: Glowacki Bartek A.
Published: March 2009

In this article it has been emphasized that superconductivity is only the enabling
technology for Super-MAGLEV and the superconducting transmission lines, because all the cost is
in cryogenic engineering, electrotechnology and general engineering infrastructure. So if in the long
term the hydrogen economy can be combined with superconducting cables and ultra fast trains
running in the same vacuum tunnel network, it will be the forerunner to a transportation and energy
transfer revolution called SuperTransGrid. In such a system, hydrogen fuel could be provided for
energy storage and transfer, very effectively cooling high power superconducting cables, but would
also feed low-pollution Cryoplanes and fuel-cell powered cars transporting passengers at speeds
~2000 miles/hour.
High Pressure High Temperature (HPHT) Synthesis and Physical Characterization of Magneto-Superconducting RuSr2Tb1.5Ce0.5Cu2O10 Ceramic Compound
Authors: Ubaldini Alberto , Awana V.P.S. , Balamurugan S. , Takayama-Muromachi E.
Published: March 2009

The ruthenocuprates family is a very interesting class of materials, because of the
coexistence of superconductivity and magnetic ordering. Ruthenocuprates include
RuSr2RECu2O8 and RuSr2(RE,Ce)2Cu2O10- (RE = rare earth elements or Y). It is possible to
synthesize samples of these phases with Gd, Eu or Sm with normal synthesis conditions. For
the others high-pressure high-temperature (HPHT) synthesis is required. We had successfully
synthesized the RuSr2Tb1.5Ce0.5Cu2O10 by HPHT technique, starting from RuO2, SrO2, Tb4O7,
CeO2, CuO and Cu. Around 300 mg of the mixture was allowed to react in a flat-belt-typehigh-
pressure apparatus at 6GPa and 1200 °C – 1550 °C. The optimised temperature of
synthesis was found to be in the range between 1350 °C – 1450 °C. The as-synthesized
compound crystallized with a structure belonging to the space group I4/mmm. DC magnetic
susceptibility versus temperature plot for RuSr2Tb1.5Ce0.5Cu2O10 in an applied field of 10 Oe
demonstrated magnetic transition at 150 K but the superconducting transition was not clearly
observed. To our knowledge this is the first successful synthesis of the Tb based Ru-1222
phase.
Growth of Bi-Pb-Sr-Ca-Cu-O Films by Organic Chemical Spray Pyrolysis Deposition
Authors: Díaz-Valdés Elvia , Castillo-Apodaca Ernesto , Mejía-García C. , Contreras-Puente G.S.
Published: March 2009

Bi-Pb-Sr-Ca-Cu-O films were deposited at 270-420°C by organic chemical spray
pyrolysis deposition with triphenyl bismuth (TPB), Pb(tmhd)2, Sr(tmhd)2, Ca(tmhd)2 and Cu(tmhd)2
(tmhd: 2,2,6,6-tetramethyl-3,5-heptanedione). A factorial experimental design was applied in order
to study the interaction between composition, deposition temperature, annealing time and annealing
temperature and the effect in the formation of crystalline phases. Results of their structural and
chemical characterization are presented.
Normally Closed Microgrippers Based on Diamond Like Carbon Structures
Authors: Luo J.K. , Fu Y.Q. , Flewitt A.J. , Spearing S.M. , Fleck N.A. , Milne W.I.
Published: March 2009

Highly compressively stressed diamond-like carbon and polymer films were used to
fabricate normally closed microgrippers with diameters as small as 30~40μm. The microgrippers
consisted of a DLC layer of 30-50nm, a thin Al layer of 40nm as a heater and an SU8 layer of
250~500nm, and were fabricated by a self-aligned two-mask process. Electrical tests and nonelectrical
tests on a Peltier device confirmed the devices have an operation temperature of ~100°C
for an opening angle of 90°, much lower than the ~400°C needed for previously fabricated
Ni/DLC microgrippers. This value is consistent with finite element modelling and analytical
calculation. The power needed to open the microgripper was only ~10 mW, less than half of those
used for the previous Ni/DLC microgrippers. It has been successfully demonstrated that the
microgrippers can be used to capture and confine micro-objects using microbeads for the tests.
Carbon Materials in Biochemistry and Biophysics
Authors: Kohn Erhard , Manfredotti Claudio
Published: March 2009

Bio-chips need active surfaces for sensing, actuation, synthesis and analysis. Thus,
they should be realized with materials, widely suppressing corrosion and hydrolysis in combination
with conducting, semiconducting and insulating properties, biocompatibility and chemical inertness.
An ideal candidate is diamond. Two forms are considered: single crystal and nanocrystalline
diamond, the later also containing non-diamond phases and graphic grain boundaries. Their surface
properties and functionalization are discussed together with their electrode, ISFET and cell
attachment and related neuron activity characteristics. Furthermore an outlook is given for system
approaches.
Electrocatalytic Behaviour of Diamond Electrode for Organic Compound
Authors: Li Rong Bin , Zhao Bin Yuan
Published: March 2009

The electrochemical behavior of a boron-doped diamond film electrode prepared by chemical
vapor deposition was studied. The surface microstructure of the electrode was studied by means of
scanning electron microscopy. The electrochemical behavior of the electrode was investigated by
cyclic voltammetry and AC Impedance. The diamond films exhibited a “cauliflower-like”
morphology and contained microcrystallites. The results showed the electrode having a very wide
potential window and very low background current. The potential windows in acidic, neutral or
alkaline medium were respectively 4.4[V], 4.0[V] and 3.0[V]. The background current was as low
as -8×10-6～5×10-7[A]. In the electrolyte including Ferri/Ferrocyanide, the electrode surface kept
good activity, and the electrochemical reaction occurring on the surface was a diffusion-controlled
reaction, with good quasi- reversibility. Compared with Pt and graphite electrodes, diamond
electrodes can oxidize compounds like phenol effectively, and the process of oxidization was very
simple and complete.
Purification of Multi-Walled Carbon Nanotubes Grown by Thermal CVD on Fe-Based Catalyst
Authors: Dikonimos Makris Th. , Giorgi L. , Giorgi R. , Lisi Nicola , Salernitano Elena , Contini Vittoria
Published: March 2009

Aiming at the purpose of using carbon nanotubes as secondary phase in composite
materials, removal of metal catalyst, catalyst support and amorphous carbon is crucial to make the
most of the required properties.
A purification method was developed to remove the metal catalyst from multi-walled nanotubes
grown by thermal CVD. A nanosized Fe-based catalyst, prepared by coprecipitation of iron and
aluminum ions, followed by solid state reaction, was used to catalyze the growth. Carbon nanotubes
were subjected to acid purification and a comparison between nitric acid and a mixture of nitric and
hydrochloric acid for the removal of Fe and Fe oxides is provided.
Morphological and spectroscopic analyses of the materials were performed, both before and after
the purification processes.
XRDT and TEM Study of Defects and Polytypism in Natural Moissanite and Synthetic SiC Crystals
Authors: Tempesta G. , Agrosì G. , Capitani G.C. , Scandale Eugenio
Published: March 2009

Structural defects and degree of order of natural and synthetic moissanite have been investigated by
XRD Topography and TEM. XRDT analyses of synthetic 6H-SiC wafers allowed to study extended
defects and to identify and localize coalescence of polytypes. The observed linear defects are microchannels
and dislocations. Axial screw dislocations, either parallel or slightly inclined to the c-axis,
suggest that the growth mechanism for the bulk crystals was mainly by spiral growth. Moreover, the
study of line orientations of the dislocations allow to reconstruct the growth sector evolution of the
sample. Therefore, the convex shape of the growing surface is attained by the development of
growth sectors (10l) neighbouring growth sector (001).
The coalescence of a thin lamella of a different polytype has been also localized and investigated.
The contrast analysis and the diffraction pattern of the lamella are consistent with a 15R-SiC
crystal. Such coalescence indicates local variations of growth conditions.
TEM images and selected area electron diffractions (SAEDs) strongly differentiate natural from
synthetic samples. SAED patterns with [010] incidence of natural crystals are consistent with the
6H polytype and do not show streaks along the [001] stacking direction. Synthetic samples are
comparatively much more disordered. Conventional images show high density of (001) faults, not
observed in natural samples. Consistently, SAED patterns of the [100] zone are streaked along c*.
High resolution (HR) imaging shows that synthetic samples mainly consist of (001) stacking
sequence described as (32)3. Locally mixed stacking sequence described by notation 23(3233)5,
probably referred to a long period polytype, are present.
Surface Conductivity of Diamond: A Novel Doping Mechanism
Authors: Ristein Jürgen , Strobel Paul , Ley Lothar
Published: March 2009

One of the most amazing features of diamond is the p-type surface conductivity which
occurs when intrinsic material is hydrogen terminated and brought into contact with appropriately
chosen adsorbates. Experiments during the last decade have revealed the different roles of the
surface acceptors and of the covalent carbon-hydrogen surface bonds: providing unoccupied
electronic states, and lowering the energy barrier for electron transfer from the diamond,
respectively. The simplest and historically first method to supply surface acceptors, i.e. exposing
hydrogenated diamond to air, provides, unfortunately, the most complex electronic system acting as
surface acceptors, namely solvated ions within atmospheric wetting layers. In that case electron
transfer is accompanied by a red-ox reaction that finally induces the hole accumulation.
A much simpler case of transfer doping has been demonstrated for C60F48 as molecular surface
accpeptors. In this case, the doping yield as a function of surface coverage can be modelled
quantitatively by the transfer doping mechanism. Also, pure C60 can be adopted for transfer doping,
but the formation of the van-der-Waals solid is required in this case to circumvent the electron
correlation energy for charge transfer to a single fullere cage. The C60 layers can be stabilized by
oxygen-mediated polymerisation without loosing their doping efficiency.
Strong Biomimetic Hydroxyapatite Scaffolds
Authors: Deville Sylvain , Saiz Eduardo , Nalla Ravi K. , Tomsia Antoni P.
Published: March 2009

Despite extensive efforts in the development of fabrication methods to prepare porous
ceramic scaffolds for osseous tissue regeneration, all porous materials have a fundamental
limitation- the inherent lack of strength associated with porosity. Shells (nacre), tooth and bone are
frequently used as examples for how nature achieves strong and tough materials made out of weak
components. So, the unresolved engineering dilemma is how to create a scaffold that is both porous
and strong. The objective of this study was to mimic the architecture of natural materials in order to
create a new generation of strong hydroxyapatite-based porous scaffolds. The porous inorganic
scaffolds were fabricated by the controlled freezing of water-based hydroxyapatite (HA) slurries.
The scaffolds obtained by this process have a lamellar architecture that exhibits similarities with the
meso- and micro- structure of the inorganic component of nacre. Compressive strengths of 20 MPa
were measured for lamellar scaffolds with densities of 32%, significantly better than for the HA
with random porosity. In addition, the lamellar materials exhibit gradual fracture unlike
conventional porous HA scaffolds. These biomimetic scaffolds could be the basis for a new
generation of porous and composite biomaterials.
Immobilization of Chitosan on the Plasma-Activated Poly-L-Lactic Acid Film Surface Using Evaporated Acrylic Acid as the Intermediate
Authors: Huang Chih Ling , Lin Ying Yi , Liao Jiunn Der
Published: March 2009

Nerve bridging is to suture a biomaterial-made conduit and to overpass the damaged
nerve end to end with microsurgery. Poly L-lactide (PLLA) is an excellent biomaterial that has
biocompatible, biodegradable and good mechanical properties; it is thus potential to be engineered as
nerve conduits and manufactured as scaffolds for nerve tissue replacement. On the other hand,
chitosan provides cell affinity and considerably promotes nerves regeneration. This study is to apply
plasma processing for PLLA film modification, graft the plasma-modified film with vaporized
acrylic acid (AAc) monomers and then immobilize chitosan by amide bonding on the pAAc-grafted
surface. This work using plasma-activation and subsequent evaporation of AAc greatly avoids PLLA
thermal cracking and remaining the PLLA film in good mechanical properties. Surface morphologies
are evaluated by Nano Focus. Electron Spectroscopy for Chemical Analysis (ESCA) and Attenuated
Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR) are respectively employed
for determining elements’ functionalities and chemical structures. Moreover, biological
functionalities of the chitosan-immobilized PLLA films are thereafter assessed by antibacterial test
and in vitro fibroblastic cell growth assay. The result exhibits that chitosan is immobilized on the
modified PLLA films, which is plasma-activated subsequent to the evaporation of AAc. The process
does not induce thermal cracking. In vitro fibroblastic cell growth assay on the
chitosan-immobilized PLLA films has demonstrated that fibroblast cells on the surface become
circular in shape. It decreases cell growth rate and the development of scar tissues, which may
thereafter promote the effect of nerve repairing.
Drug Release from Hydroxyapatite Implants with Different Microstructure and Phase Composition
Authors: Zima Aneta , Mycek B. , Ślósarczyk Anna , Szymura-Oleksiak J. , Paszkiewicz Zofia
Published: March 2009

The goal of our studies has been to determine under in vitro conditions the amount and rate of
pentoxifylline release from the samples of modified hydroxyapatite [HAp-Ca10(PO4)6(OH)2]
implants in the form of microporous blocks (heterogeneous system) as well as from hydroxyapatitegypsum
pellets (homogeneous system). For the preparation of microporous hydroxapatite ceramics
additives of calcium metaphosphate Ca(PO3)2 (5 and 10 wt. %) or hydrated magnesium
orthophosphate Mg3(PO4)2·8H2O (10 wt. %) were used as modifiers. In the case of drug release
from heterogeneous carriers, cylinders filled with 50 mg of PTX were used. In the homogeneous
system the pellets made of HAp and CaSO4·1/2H2O powders with homogeneously incorporated of
50 mg PTX were applied.
It has been shown that the process of drug release from multifunctional ceramic implants depends to
a significant degree on the microstructure of the materials, and the type of carrier system
(heterogeneous or homogeneous).