bluuebunny/crossref_metadata_2025 huggingface dataset:
Harmonic Generation and Mixing with the W–Ni Point Contact Diode in the Far-Infrared
Authors: Kurosawa Tomizo , Sakurai Toshio , Morinaga Atsuo
Published: November 2005

The S/N ratio of the beat note obtained from frequency mixing between a 469-µm CH3OH laser and a 71-GHz klystron was measured as a function of the incident power of the CH3OH laser and the klystron on a W–Ni point contact diode. A beat note with a S/N ratio of 35 dB was obtained during frequency mixing for simultaneous oscillations of the 469- and 251-µm lines.
Interstitial Air Pressure Dependence of Effective Thermal Conductivity and Diffusivity of Rajasthan Desert Sand Using Transient Hot-Strip Method
Authors: Saxena N. S. , Chohan M. A. , Gustafsson S. E.
Published: November 2005

The transient hot strip (T H S) method used for the simultaneous measurement of effective thermal conductivity and diffusivity of loose granular two-phase materials at normal pressure and room temperature is now used for the measurement of effective thermal conductivity and diffusivity of Rajasthan Desert sand at different interstitial air pressure and room temperature. Experimental values of effective thermal conductivities and diffusivities at different interstitial air pressures have been compared with the estimated values using empirical models for the variation of thermal conductivity and diffusivity with interstitial air pressures. Estimated values are in good agreement with the experimental results in the interstitial air pressure range from 1 mm to 760 mm of mercury, whereas in the low pressure range (0.1 mm to 1 mm Hg) deviations from the experimental results have been observed.
Characteristics of Optical Switching and Memory Effects Utilizing Deformation of Helicoidal Structure of Ferroelectric Liquid Crystals with Large Spontaneous Polarization
Authors: Kishio Shin-ichi , Ozaki Masanori , Yoshino Katsumi , Sakurai Takao , Mikami Naoko , Higuchi Ryo-ichi
Published: November 2005

The anomalous voltage-transmission hysteresis of ferroelectric liquid crystals associated with the unwinding and winding of a helicoidal structure was studied in detail. Utilizing this phenomenon in newly developed ferroelectric liquid crystals with an extremely large spontaneous polarization, it is indicated that a bistable switching and memory element with a reasonable working voltage and response time can be realized.
Electron Relaxation Properties and Transient Spectroscopy of Hydrogenated Amorphous Silicon
Authors: Han R. Q. , Tua P. F. , Ruvalds J. , Ngai K. L.
Published: November 2005

The isothermal-capacitance-transient-spectroscopy (ICTS) and the deep-level-transient-spectroscopy (DLTS) data of a-Si:H are analyzed using a model based on the electronic relaxation theory of Ngai and coworkers. The electron capture and emission processes are taken into account in a selfconsistent manner, and are described by relaxation functions with the same fractional exponent, i.e., φ(t)αexp
[-(t/τ*)1-λ], where λ=0.2 and τ* is energy dependent in both processes. This approach (i) explains the anomalous energy and temperature dependence of the effective relaxation rate obtained by the ICTS method and (ii) yields an explanation for the energy difference of the D- states between ICTS and DLTS measurements.
Estimation of Radiation Damage and Pattern Resolution in Ion Direct Writing Using Scattering of Low Energetic Ions
Authors: Hosaka Sumio , Ishitani Tohru , Tamura Hifumi
Published: November 2005

An estimation of the radiation damage and pattern resolution in ion direct writing is presented by a Monte Carlo simulation of the slowing down and scattering of low-energy ions and recoiled atoms in an amorphous target. The simulation program is characterized by employing the power of a logarithm approximation as a screening function, the distance between collisions and a modified step length based on a binary collision model. Calculated results are in terms of radiation damage depth and fine pattern resolution using sputtering and radiation damage as a semiconductor fabrication technique. Consequently, available informations can be obtained as ion lithography using sputtering and radiation damage that has a much finer pattern resolution (less than a few 10s Å) than electron beam lithography using a latent resust image.
Plastic Deformation of Ionic Crystals: Statistical Analysis of Yield Stress Measurements
Authors: S. J. Soullard , A. A. Mendoza , M. E. Orozco , A. J. Montemayor
Published: November 2005

Statistical methods of data analysis were used to study yield stress measurements of ionic crystals. First, the effect of specimen geometry on the reproductibility of yield stress measurements were studied in order to determine the optimum dimensions and shape of the specimen so as to obtain the most reproductibile measurements. Secondly, the causes of inconsistencies between values of n (the exponent of the power law which expresses the variation of the yield stress gainst impurity concentration) were investigated. A set of values of n obtained with various regression methods and various superposition laws to calculate the impurity-induced-hardening were analyzed by using the variance analysis method. Results of the analysis show that the choice of a superposition law influences the determination of n. The choice of a superposition law together with the lack of a characterization of the aggregation state of impurities are thought to be the main causes of discrepancies between the values of n published over the last ten years.
Investigation of Switching Characteristics of Vinylidene Fluoride/Trifluoroethylene Copolymers in Relation to Their Structures
Authors: Tajitsu Yoshiro , Ogura Hiroshi , Chiba Akio , Furukawa Takeo
Published: November 2005

Ferroelectric switching characteristics of VDF/TrFE copolymers have been investigated over the entire range of composition for the samples subjected to drawing and/or annealing. Switching phenomena were most remarkably observed in the copolymers containing 50–80 mol% VDF. The as-cast copolymer exhibits no switching behavior because of high a depolarization field associated with low crystallinity. Draw-induced orientation of the chain axis parallel to the film surface causes an increase in the amount of reversed polarization. Annealing at a temperature between the Curie point and the melting point results in a significant increase in the degree of crystallinity and the amount of reversed polarization. Extrapolating to 100% crystallinity allows an estimation of spontaneous polarization, which is 120–135 mC/m2 for the 73/27 mol% copolymer. This value suggests a small Lorentz factor in crystals of VDF/TrFE copolymers.
Fluorescence from Pearls to Distinguish Mother Oysters Used in Pearl Culture
Authors: Miyoshi Tadaki , Matsuda Yasunori , Komatsu Hiroshi
Published: November 2005

The fluorescence spectra of pearls and shells of Pteria penguin (mabe), Pinctada fucata (Japan's Akoya oyster) and Pinctada maxima (yellow lip oyster) have been measured in order to distinguish species of the mother oyster which produce that pearl. A distinction is possible for these pearls using differences in the fluorescence spectra. The spectral difference has been attributable to colouring matter or screloprotain in pearls and shells.
A Method for the Energy Analysis of Electrons in the Presence of Trapped Electrons
Authors: Honzawa Tadao
Published: November 2005

A method for the energy analysis of electrons in the presence of trapped electrons has been developed. This was actually applied to measurements of electron distribution functions, including both free and trapped electrons in shock experiments. Finally, it was found from comparing the characteristic curves that this method has a great advantage over the probe technique for the purpose described above.
CO2 Laser Detection Using a Warm Carrier Device Fabricated by Evaporated Ge Films
Authors: Inoue Narumi , Yasuoka Yoshizumi
Published: November 2005

Polycrystalline germanium films with a thickness of 600 nm were deposited on glass substrates by vacuum evaporation and used for the first time as antenna-coupled point-contact warm carrier devices.
Devices fabricated by using a Ge film deposited at a substrate temperature of 640°C were successfully used to detect a CO2 laser.
Compensation Effect in Electrical Conduction Process and Molecular Geometry
Authors: Mitra Bani , Misra T. N.
Published: November 2005

Compensation effect in the electrical conduction process has been observed in 15-15' cis β-carotene crystal. The results suggest that molecular geometry play an important role in the way compensation effect is manifested. Various conduction parameters have been calculated.
Liquid Phase Epitaxial Growth of lnGaAsP on GaAs1-yPy Substrates (y=0.31 and 0.39)
Authors: Fujimoto Akira , Shimura Mikihiko , Watanabe Hideaki , Takeuchi Masashi
Published: November 2005

Lattice matched InGaAsP mixed crystals with various energy bandgaps were grown by liquid phase epitaxy (LPE) on GaAs1-y
P
y
substrates (y=0.31 and 0.39). The growth layers had smooth and shiny surfaces with undulated morphology reflecting the cross-hatching pattern of GaAsP substrates. The influences of offset angle and crystal composition of the InGaAsP growth layer on the surface morphology of the InGaAsP growth layer were investigated. The offset angle was not the main cause of the undulated morphology in our experiments. Photoluminescence spectra and X-ray rocking curves of the growth layers were measured in order to determine their energy bandgaps and lattice constants. The doping characteristics of zinc and tellurium were also investigated. The growth conditions and properties of the InGaAsP layers on GaAsP substrates are described in detail.
Thermally Stimulated Current Due to Dipolar Depolarization under a Temperature Gradient
Authors: Kato Keizo , Iwamoto Mitsumasa , Hino Taro
Published: November 2005

A thermally stimulated current measurement using a temperature gradient (TG–TSC measurement) has been applied to the study of dipolar depolarization in polymers. TG–TSC in the initial rise region has been theoretically analyzed and the effect of a temperature gradient has been clarified. The theoretical relation between TSC and TG–TSC is considered and a formula for TG–TSC is presented. We conclude that the experimental results on a cross-linked polyethylene (XLPE) film can be explained using the above relation and that the characteristics obtained from the above theoretical analysis can be used for ascertaining the presence of a constant temperature gradient in a film.
Sputter Type HF Ion Source for Ion Beam Deposition Apparatus
Authors: Yamashita Mutsuo
Published: November 2005

A sputter-type HF(high-frequency) ion source was developed. The L-coupled high-frequency discharge phenomenon was combined with DC diode sputtering to enhance the plasma density. A high-density plasma of 3×1012 ions/cm3 was effectively generated at an HF power of 300W, since the plasma could almost be confined in the limited space of a target, an HF coil and an ion extraction aperture electrode. Then, most of the solid source materials were effectively vaporized by high-rate sputtering (400 Å/s for Cu target) in the ionization region and were simultaneously highly ionized. The excess energy and the energy spread ΔE of the extracted ion beam were 13.5 eV and 7.8 eV, respectively. The maximum ion current of the mass separated Cu+ current was 530 µA without deceleration, under the conditions of an Ar sputter gas pressure of 1×10-1 Torr (1.33×101 Pa), HF power of 300W, and an extraction voltage of 10 kV, respectively.
Direct Measurement of the Switching Waveform in a DC–SQUID
Authors: Fujimaki Akira , Nakajima Koji , Sawada Yasuji
Published: November 2005

A high-resolution Josephson sampler using a single fluxoid is fabricated. The sampling pulse generator comprised a two-junction interferometer (DC–SQUID) with a damping resistance resistively coupled to a single junction as the sampling gate to reduce a turn-on delay. An ultra-fast sampling pulse was generated at a vortex-to-vortex transition in this sampler. The fabricated sampler had less than a 5ps time resolution and about a 5 µA current sensitivity. The dynamic waveform associated with two kinds of transitions was observed by the use of this sampler: a vortex-to-vortex transition and a vortex-to-voltage transition. The results show that the pulse corresponding to a single fluxoid has a nearly constant pulse height that is independent of the bias current and that setting the bias current near the critical point results in the long rise time of a DC–SQUID.
X-Ray Diffraction Characterization of Cadmium Stearate Langmuir-Blodgett Films
Authors: Mizushima Koichi , Nakayama Toshio , Azuma Makoto
Published: November 2005

The X-ray 00l Bragg peak intensities were analyzed for multilayer Cd stearate films deposited by the Langmuir Blodgett method on glass, aluminum and SiO2 substrates. Most of the samples were found to be a mixture of regular and disordered layer structures. One sample on a SiO2 substrate was found to have a regular layer structure like a single crystal containing no disorder.
The Grotesques of Oval Defects on the MBE-Grown GaAs Layers
Authors: Chou Y. C. , Lee C. T.
Published: November 2005

In addition to the regular oval defect, two grotesque features, named pyramidal and ellipsoidal shaped defects, have been observed on MBE-grown GaAs layers. Those grotesque defects were demonstrated to have come from a foreign contamination of the Ga source. A method for reducing those defects is also proposed.
Ferroelectric Crystal of Ba2Bi1/3Nb5O15
Authors: Sugai Tokukō
Published: November 2005

A new orthorhombic crystal, Ba2Bi1/3Nb5O15 of the tungsten-bronze-type structure was found to be ferroelectric with a Curie temperature of 240°C. Large single crystals were grown by the method of pulling from a melt; also, dielectric measurements were made of the single crystals and their ceramic specimens.
Tunable Optical Band Pass Filter Using Optically Active and Biaxial Crystals
Authors: Horinaka Hiromichi , Miyauchi Takeshi
Published: November 2005

A tunable optical band-pass filter using an optically active, optically biaxial crystal is proposed. In a biaxial crystal, the direction of the optical axis generally depends on the wavelength. This filter capitalizes on this property and the optical activity. The filter contains a crystal sandwiched between a polarizer and an analyzer which are set in a crossed-Nicol position. The central wavelength can be selected by changing the direction of the light propagation in the crystal by rotating the crystal.
Effect of the Ti Sublayer on the Structural and Magnetic Properties of Evaporated CoCr Film
Authors: Tanaka Toshikazu , Masuya Haruko
Published: November 2005

A Ti sublayer tends to align the c-axes normal to the film plane and to promote the growth of columnar grains in evaporated CoCr film. The effect of a Ti sublayer on the c-axis orientation may be similar to the effect of epitaxial-growth.
The Ti sublayer improves the magnetic properties of CoCr film: the saturation magnetization M
s, the perpendicular magnetic anisotropy constant, the coercivity and the squareness ratio in the perpendicular hysteresis loop increase. The Ti sublayer also serves to limit the reduction in M
s with an increase in temperature. The smaller reduction in M
s with increasing temperature and the increase in M
s which are attributable to the Ti sublayer imply that the Ti sublayer tends to increase the amount of Cr segregation.
Optimum Design of Detection Coil System for Vibrating Sample Magnetometer
Authors: Nagata Shoichi , Fujita Eiji , Ebisu Shuji , Taniguchi Satoshi
Published: November 2005

The optimum design of a detection coil system for Foner-type vibrating sample magnetometers is discussed. It was found by an analysis based on numerical computations that one of these coil configurations has an extremely broad saddle point for sample displacements, which minimizes any undesirable influence due to sample mispositioning. These results can be applied to the conventional Foner-type magnetometers in order to improve the accuracy of measurements.
Intense Ion Beam Flux of Adsorbed Gases and Metallic Anode Materials in the “Point Pinch Diode” Measured with Thomson-Parabola Ion Spectrometer
Authors: Sato Morihiko
Published: November 2005

An intense flux of ion beams was observed in a “Point Pinch Diode” which consists of concentric elliptic or spherical electrodes and a slender magnetically insulated transmission line. The ion beam had an energy of about 380 keV, which was equivalent to the supplied diode voltage. The peak current density of the ion beam ranged from 5 to 7.5 kA/cm2 in spite of a small input energy (less than about 1 kJ). Measurements with a Thomson-parabola ion spectrometer show that the major components were hydrogen, carbon, and oxygen, the origins of which were oil and water adsorbed on the surface of the metallic anodes. A significant flux of the metallic ion beams was also detected in the cases of aluminium, copper and gold anodes.
Measurement of Heat Capacity under Hydrostatic Pressure between 0.5 K and 15 K
Authors: Takeda Kazuyoshi , Wada Masaru , Inoue Mitsuru , Haseda Taiichiro
Published: November 2005

An experimental method for measurement of the low-temperature heat capacity at hydrostatic pressures and external magnetic fields was developed. Also, a suitable pressure-transmitting medium (Apieson-J oil) was found which had good thermal properties for the present method to measure the thermal and magnetic properties of a single crystal of CuCl2·2H2O (T
N=4.33 K) at hydrostatic pressures of up to 6 kbar.
Analysis of Non-Gaussian Speckle by Nakagami m-Distribution
Authors: Yoshikawa Manabu , Kayano Hiroshi
Published: November 2005

The photon counting distribution of laser light scattered by a ground glass is analyzed by applying Nakagami's m-distribution to the intensity fluctuations of the speckle pattern for which the statistics are non-Gaussian. Based on the comparison of the moments between the experimental and theoretical values, we show that the experimental data can be described by the Nakagami's m-distribution.
The Effect of Fe Concentration in Substrates on the Characteristics of InP MISFETs
Authors: Okamura Masamichi , Hirota Yukihiro , Yamaguchi Eiichi , Mikami Osamu
Published: November 2005

The relationship between the characteristics of accumulation-type InP MISFETs and the Fe concentrations in their semi-insulating sustrates has been investigated. It was learned that the effective electron mobilities decrease with an increase in the Fe concentration. It was also observed that the threshold voltages shift in the positive direction with an increase in the Fe concentration.
Microcrystallization in P-Doped Si:H Films at High Deposition Rate
Authors: Ueda Masato , Imura Takeshi , Osaka Yukio
Published: November 2005

A new preparation process for the microcrystallization of hydrogenated silicon (Si:H) doped heavily with P has been observed under conditions such as a high deposition rate of about 4.5 nm/s and a high substrate temperature of 470°C without a strong hydrogen dilution of silane; this is really unusual in comparison with that for microcrystalline formation in conventional low-rate-deposited Si:H films. The existence of P atoms and the reduction of H atoms on the growth surface enhance the microcrystallization of high-rate-deposited films.
Preparation Method and Optoelectrical Properties of a-Se/CdxSe1-x Multilayer Films
Authors: Shirai Hajime , Oda Shunri , Nakamura Tetsurō , Shimizu Isamu
Published: November 2005

The preparation of multilayer films consisting of alternate a-Se and Cd
x
Se1-x
structures with a periodic distances ranging from 40 to 400 A is discussed. An investigation of the chemical structure of the resulting films and their optoelectrical properties revealed a strong dependence on the preparation parameters and on the composition and the design of the films. These evaluations also indicated that the multilayered structure did not give rise to additional deep trapping states, in spite of the high number of layer interfaces.
Microscopic Observation of Undercooled Silver-Gold Alloy Droplets
Authors: Asahi Nobuo
Published: November 2005

The solidification behaviour of undercooled Ag–Au alloy droplets with about 0.05 mm diameter has been observed using a high-temperature microscope.
In this alloy system, the ratio of the maximum amount of undercooling to the liquidus temperature of each alloy composition ranged from 0.170 to 0.180 and a growth of a dendritic structure was almost always observed in the cross section of each droplet after solidification.
It was found from the results that the solidification of undercooled Ag–Au alloy droplets behaved in the same way as that of undercooled pure silver or pure gold.
Preparation of Polycrystalline Silicon by Hydrogen-Radical-Enhanced Chemical Vapor Deposition
Authors: Shibata Naoki , Fukuda Kaichi , Ohtoshi Hirokazu , Hanna Jun-ichi , Oda Shunri , Shimizu Isamu
Published: November 2005

The preparation of both amorphous and epitaxial crystalline silicon films by Hydrogen-Radical-Enhanced Chemical Vapor Deposition at variable hydrogen flow rates is discussed. The feasibility of fabricating polycrystalline Si at high growth rates and a low substrate temperature is demonstrated. Finally, the n-type characteristics of PH3 doping and p-type characteristic for BF3 doping are examined in terms of the conductivity and the Hall mobility of the films.
Heat Pulse Method for Determination of Thermal Diffusivity of Liquid Crystals
Authors: Akahane Tadashi , Kondoh Masumi , Hashimoto Kenji , Nakagawa Masahiro
Published: November 2005

A heat pulse method for determination of thermal diffusivity of liquid crystals is described. It is based on measurement of temperature rise by a sensing electrode when a heat pulse is given by a heating electrode. From curve-fitting between experimental results and the solution of equation of heat conduction, thermal diffusivity of liquid crystals can be determined. This method is applied to 4'-n-octyl-4-cyanobiphenyl and the anisotropy and the temperature dependence of its thermal diffusivity are measured.
High Temperature Superconductivity in Mixed Metal Oxides Containing Yttrium
Authors: Jayaram B. , Agarwal S. K. , Gupta A. , Narlikar A. V.
Published: November 2005

Mixed metal oxides Y-Ba-Cu-O have been prepared with Y:Ba:Cu in 1:2:3 and 2:2:3 ratios and their superconductivity has been investigated. The effect of replacing Ba by Sr on T
c has been systematically explored. Results indicate the possibility of superconducting transition above 230 K.
Gamma-Ray Induced 2 eV Optical Absorption Band in Pure-Silica Core Fibers
Authors: Nagasawa Kaya , Ohki Yoshimichi , Hama Yoshimasa
Published: November 2005

Gamma-ray induced 2 eV band appears at different wavelengths depending on the OH-group content. It is found that 2 eV band formed in low-OH content fibers, formerly ascribed to another precursor, is caused by non-bridging oxygen hole centers (NBOHC, Si-O·), as is the one formed in high-OH content fibers. The differences in peak wevelength and in oscillator strength are responsible for hydrogen bonding between NBOHC and a nearby OH-group. The NBOHC with a hydrogen bond in the shape of Si-O····H-O-Si formed more in high-OH content fibers absorbs light around 600 nm, while it absorbs around 630 nm when it exists without forming a hydrogen bond (Si-O·).
High Speed Response in Optoelectronic Gated Thyristor
Authors: Tashiro Yoshiharu , Kasahara Kenichi , Hamao Noboru , Sugimoto Mitsunori , Yanase Tomoo
Published: November 2005

High speed response in a three terminal p
n
p
n double heterostructure optoelectronic gated thyristor is demonstrated. The gate electrode on the active layer is operated to sweep out excess carriers in the active layer. The turn-off delay time has been measured to be 5 ns, which is two orders of magnitude improvement compared with that for the two terminal mode operation. Furthermore, it has been shown that the turn-off delay time cannot be estimated from the conventional 90-10% fall time.
Superconductivity at 90 K in the Y-Ba-Al-Cu-O System
Authors: Escudero R. , Rendon-Diazmirón L. E. , Akachi Tatsuo , Heiras J. , Vázquez C. , Baños L. , Estrada F. , González G.
Published: November 2005

The addition of small quantities of Al atoms to the Y-Ba-Cu-O system has been studied. A superconducting transition at 90 K has been observed in a new Y-Ba-Al-Cu-O compound system, by resistance measurements. The superconductivity is stable and reproducible after several heat cycles.
DC SQUID Operation at 77 K Using All Ceramics Josephson Junctions
Authors: Iguchi Ienari , Sugishita Akimitsu , Yanagisawa Manabu
Published: November 2005

The first successful dc SQUID operation at 77 K utilizing Y-Ba-Cu-O bulk ceramics Josephson junctions is reported. The observation of clear periodic patterns due to the macroscopic quantum interference effect assures promising applications of this device at liquid nitrogen temperature.
Superconductivity Transition and Crystal Structure of the High-Tc and High-Hc2 Superconductor DyBa2Cu3O7-δ
Authors: Takita Kôki , Akinaga Hiroyuki , Katoh Hideo , Ishigaki Tōru , Asano Hajime
Published: November 2005

Superconductivity transitions of DyBa2Cu3O7-δ in the magnetic field up to 9 T are described together with the crystal structure analysis of the same samples by X-ray powder diffraction combined with Rietveld analysis. A very sharp transition at 93 K with the transition width of 1.2 K in zero magnetic field is observed and the width is still small even in the magnetic field. The upper critical field H
c2 near T
c is very large; the offset field H
c2
off defined at 1 % points is 10 T even at 80 K and the slope (-dH
c2/dT) for midpoint is 5.5 T/K. According to the structure analysis, single phase with orthorhombic structure is responsible for the high-T
c and high-H
c2 superconductivity in DyBa2Cu3O7-δ as in YBa2Cu3O7-δ and RBa2Cu3O7-δ (R = Ho or Er).
Large Area Chemical Vapour Deposition of Diamond Particles and Films Using Magneto-Microwave Plasma
Authors: Kawarada Hiroshi , Mar King Sheng , Hiraki Akio
Published: November 2005

Large area chemical vapour deposition of diamond has been obtained using magneto-microwave plasma. The important point of the developed system is to set the electron cyclotron resonance condition (875 G), where the highest plasma density is expected, at the deposition area by controlling the distribution of an applied magnetic field. Even in 10 Torr where complete electron gyrations cannot be expected, the size of the discharge area controlled by the magnetic field is 70-80 mm in diameter. This value is the largest of all plasma deposition systems of diamond. The crystallinity obtained by the above-mentioned plasma compares favourably with those of the best ones by previous methods.
Nonlinear Surface Polaritons in Thin Films: TM Case
Authors: Kushwaha Manvir S.
Published: November 2005

We demonstrate that analytically realistic and physically significant solutions for nonlinear TM modes are possible in the transverse uniaxial approximation [ε

z
z
(E

z

2)] if one resorts to working with the transverse electric field component E

z
. The dispersion relation and the time-averaged power carried by the waves guided by a thin film asymmetrically bounded by optically nonlinear, semiinfinite, dielectric media are derived. The analytical and numerical diagnoses compared with the earlier results based on “Hy-treatment” reveal an appreciable difference in the results.
Generation of Magnetic Islands Caused by Periodical Nonuniformity of Axial Magnetic Field for FRC Formation Phase
Authors: Ogi Sukeomi , Shiratani Masaharu , Watanabe Yukio
Published: November 2005

An experiment is done with respect to the formation of magnetic islands in FRC caused by nonuniformity of an applied magnetic field near the tube wall. It becomes evident experimentally that magnetic islands are formed not around all gaps between sub-coils but around some of them. This result cannot be explained by the existing theories on the formation of magnetic islands.
The Anisotropic Upper Critical Field of Single Crystal YBa2Cu3Ox
Authors: Iye Yasuhiro , Tamegai Tsuyoshi , Takeya Hiroyuki , Takei Humihiko
Published: November 2005

We report a study of anisotropic upper critical field of single crystal samples of orthorhombic YBa2Cu3O
x
. The critical field shows anisotropy characteristic of a quasi-two-dimensional superconductor, and is highest when the field is oriented perpendicular to the c-axis. For this field direction, the zero resistance state persists up to 86 K in a magnetic field of 90 kOe, which is lower by only 5 K than the zero resistance temperature in the absence of magnetic field. The anisotropy H
c2
⊥/H
c2
// is about 2 at 90 K, 5 at 86.5 K and tends to increase with decreasing temperature.
InSb-MAOS Structure Fabricated by Anodization and Sputtering
Authors: Fujisada Hiroyuki
Published: November 2005

A InSb-MAOS structure is fabricated by anodic oxidation and alumina sputtering. Effects of the thickness of the anodic oxide and thermal annealing on interface properties are described. The anodic oxide is not only an excellent gate insulator but also plays a buffer role in alumina sputtering. A thickness of 34 nm is minimum to avoid the sputtering damage. Any thermal annealing gives rise to a deterioration of interface properties, even at a low temperature of around 100°C. The InSb-MAOS structure fabricated with a low temperature process condition below 100°C shows stable C-V characteristics with small flat band voltage shift and low interface state densities.
Narrow Photoluminescence Spectra in InGaAsP/GaAs (001) LPE Layers Grown in the Immiscible Region
Authors: Kato Takamasa , Matsumoto Takashi , Ishida Tetsuro
Published: November 2005

Narrow band-to-band photoluminescence (PL) was observed in InGaAsP/GaAs (001) layers which were grown in the immiscible region at 788°C. The full width at half maximum (FWHM) of the band-to-band emission at ∼1.8 eV was about 18 meV at 77 K and about 38 meV at 300 K. The layer surface which showed such a narrow PL band was flat and smooth. The good layer was grown near the substrate edge, where the layer was 25 µm thick. It is presumed that the strain energy induced by the substrate and the high growth rate due to the edge growth is related to the stable growth.
Reverse Hysteresis Loop of Nematic Liquid Crystals in C-V Characteristic due to Static Electric Field
Authors: Mada Hitoshi , Suzuki Hiroyoshi
Published: November 2005

A reverse hysteresis loop of nematic liquid crystals is experimentally observed in C-V characteristic driven by a DC electric field. A width of the hysteresis depends on the materials: both liquid crystal and surface aligning layer. This phenomenon can be qualitatively explained by a surface electric double layer consisting of impurity ions.
Epitaxial Growth of CuGaS2 by Metalorganic Chemical Vapor Deposition
Authors: Hara Kazuhiko , Kojima Tohru , Kukimoto Hiroshi
Published: November 2005

CuGaS2 epitaxial layers have been grown on GaAs and GaP substrates by metalorganic chemical vapor deposition for the first time, using cyclopentadienyl(triethylphosphine)copper(I), triethylgallium and hydrogen sulfide (or diethylsulfide) as source materials. The surface morphology and growth orientation are studied. The grown layers have shown green photoluminescence at low temperature.
Electron Paramagnetic Resonance Studies of Defects in Oxygen-Implanted Silicon
Authors: Fujita Tetsuo , Saitoh Yasunobu , Itoh Noriaki , Mizuno Bunji , Kubota Masafumi
Published: November 2005

Electron paramagnetic resonance measurements have been carried out on oxygen-implanted silicon at room temperatures. The EPR spectra composed of three isotropic lines are observed for the ion-dose range between 2×1017and 1.8×1018cm-2. They are ascribed to the dangling bonds in amorphous Si, to the defects in SiO2and to defects at the Si/SiO2interface. The EPR spectra ascribed to the defects in the Si/SiO2interface are found to differ from those arising from the Pb centre and from the defects at the Si/SiO2interface formed by oxygen ion implantation at high temperature.
Two-Dimensional-Electron Gas in Undoped and Selectively-Doped GaInP/GaAs Heterostructures Grown by Chloride-Vapor-Phase Epitaxy
Authors: Kitahara Kuninori , Hoshino Masataka , Kodama Kunihiko , Ozeki Masashi
Published: November 2005

This paper reports characteristics of two-dimensional-electron gas (2DEG) in GaInP/GaAs heterostructures and their availability to electronic devices. The heterostructures were fabricated by chloride-vapor-phase epitaxy. The band discontinuity was estimated using an empirical rule. A low-temperature mobility of 2DEG greater than 100,000 cm2/V·s was obtained for the undoped structure. 2DEG was also observed in S or Se selectively-doped structures without incorporating the undoped-spacer layer. Apparent temperature dependence and photoresponse of 2DEG were interpreted with the models which have been used for GaInAs/InP heterostructures.
Low-Temperature Growth of AlAs/GaAs Heterostructures by Modulated Molecular Beam Epitaxy
Authors: Briones F. , González L. , Recio M. , Vázquez M.
Published: November 2005

Modulated molecular beams phase-locked to reflection high-energy electron diffraction (RHEED) oscillations have been used to grow low-temperature GaAs quantum wells (QW) confined by AlAs/GaAs short-period superlattices (SL). Two different phase-locked modulation growth modes were attempted and compared. In the first mode, only the As4 beam was interrupted periodically in-phase with the monolayer growth cycle. In the second one, both Ga (or Al) and As4 incident beams were modulated synchronously with the monolayer period. Both growth methods were seen to produce high-optical-quality QW and SL's layers at low-growth temperatures (T
s≃400°C).
Epitaxially Induced Stress in GaAs Layer on V-Grooved Si and GaAs Substrates
Authors: Hashimoto Akihiro , Kamijoh Takeshi , Watanabe Nozomu
Published: November 2005

Raman spectra from the (01̄1) face in GaAs epitaxial layers on both V-grooved (100)-Si and -GaAs substrates were observed. Peak- shifts in the transverse-optical (TO) modes at the edge of the V-groove were observed in hetero- and homo-epitaxial structures, respectively. Additional line broadening in the TO mode was only observed in the heteroepitaxial structure. The peak-shifts result from the epitaxially induced stress and the additional broadening was due to the fluctuation of the stress.
Recrystallization of Ge on SiO2 Using SrF2 Seed by Pseudo-Line Electron Beam Annealing
Authors: Yamagishi Chouho , Kimura Tamotsu , Akiyama Masahiro , Kaminishi Katsuzo
Published: November 2005

Recrystallization of Ge on SiO2 on GaAs substrates by lateral epitaxy using SrF2 seed was studied. Trapezoidal modulation was applied for the pseudo-line electron beam annealing to obtain uniform and large single crystalline layers for the first time. Optimizing the conditions of the electron beam annealing, single crystalline Ge regions as large as 0.3 mm×0.8 mm were obtained successfully. The GaAs layer grown on Ge showed good morphology and crystallinity.
Growth of SiO2 Needles Induced by Positive Corona Discharging
Authors: Nashimoto Keiichi
Published: November 2005

Growth of needles induced by positive discharging in air containing a small amount of dimethyl-poly-siloxane (DMPS) vapor was examined. After discharging for 30 to 120 minutes in pure air containing DMPS vapor, amorphous SiO2 needles and a thin film had grown on tungsten wire anode. The needles had a hollow tube running parallel to the axis of each needle. In contrast, needles grown in just pure air contain tungsten. The growth of needles caused by plasma oxidation of DMPS and by sputtering of the tungsten wire anode owing to negative ion impinging is discussed.
Reduction of Dislocation Density in GaAs/Si by Strained-Layer Superlattice of InxGa1-xAs-GaAsyP1-y
Authors: Nishimura Takashi , Mizuguchi Kazuo , Hayafuji Norio , Murotani Toshio
Published: November 2005

Dislocation density in GaAs layers grown on Si substrates has been investigated by measuring in-depth profile of the etch pit density (EPD) using a molten KOH. Reduction of EPD into 107 cm-2 level for the layer of 2-3 µm thickness is attained by the post annealing at 900°C for 30 min. Further reduction of dislocation has been achieved using In
x
Ga1-x
As-GaAs
y
P1-y
strained-layer superlattices (SLS's); step-like reduction of the dislocation at the SLS's and its continuous decrease even passing through the SLS's have been observed.
Neutron Diffraction Study on Orthorhombic YBa2Cu3O6.74 and Tetragonal YBa2Cu3O6.05
Authors: Kajitani Tsuyoshi , Oh-ishi Katsuyoshi , Kikuchi Masae , Syono Yasuhiko , Hirabayashi Makoto
Published: November 2005

The crystal structures of high T
c (∼90 K) orthorhombic YBa2Cu3O6.74 and moderate T
c (∼50 K tetragonal YBa2Cu3O6.05 have been studied by the conventional neutron powder diffraction technique. Single phase powder samples were used.
In the orthorhombic phase, the occupancies of the O1(0 1/2 0) and the O4 sites (1/2 0 z), z=0.380(2) are found to be respectively 0.91(3) and 0.92(2). In the tetragonal phase, the occupancies of the O1(0 1/2 0) and the O3 sites (0 1/2 z), z=0.383(2) are 0.20(4) and 0.91(2). Some disordering of Ba and Y atoms is suggested in the tetragonal phase.
High Tc Superconductor YBa2Cu3Oy–Oxygen Content vs Tc Relation–
Authors: Takayama-Muromachi Eiji , Uchida Yoshishige , Ishii Motohiko , Tanaka Takaho , Kato Katsuo
Published: November 2005

High T
c superconductor YBa2Cu3O
y
, having various oxygen contents have been examined by a.c. susceptibility, d.c. conductivity and Raman spectrum measurements. The T
c is greatly affected by the oxygen content, being lowered by decreasing oxygen content. Particularly, the T
c drops markedly when the compound takes a tetragonal form. To confirm the y vs temperature relation, the compound was reexamined by thermogravimetry. The new results cast doubt on our previous y value (6.5>y>5.8).
Preparation of a High-Tc Y-Ba-Cu-O Superconductor Using Colloidal Methods
Authors: Fujiki Michiya , Hikita Makoto , Sukegawa Ken
Published: November 2005

New synthetic procedures of a Y-Ba-Cu-O superconductor obtained through homogeneous colloidal precursors are described. These are formed by hydrolysis (olation) and in situ oxidation reaction (oxolation) of a mixture of metal ions in an aqueous solution. The resulting specimens exhibit a high-T
c superconducting state after calcination. Resistance drops at around 95 K and completely vanishes at 75 K. These procedures will provide a conventional process for producing superconductive thin films and wires.
Strain-Energy-Stabilized Growth of InGaAsP Layers on GaAs (111)A Substrates in Immiscible Region
Authors: Kato Takamasa , Matsumoto Takashi , Kobatake Takaaki , Ishida Tetsuro
Published: November 2005

High quality InGaAsP layers could be grown for a short growth period, even if the growth was performed inside the immiscible region. When a quaternary solution was prepared for the growth of InGaAsP/GaAs (111)A with E

g
∼1.7 eV (77 K), a good layer with narrow PL half width was grown for a growth time shorter than 5 min. This is attributed to the stabilization of the growth by the strain energy induced by the lattice mismatch. A layer with large E

g
(∼1.8 eV at 77 K) and broad PL half width was precipitated for a growth time longer than 20 min due to the phase decomposition.
Low-Temperature Silicon Epitaxial Growth by Photochemical Vapor Deposition Using Vacuum Ultraviolet Light
Authors: Gonohe Narishi , Shimizu Saburo , Tamagawa Kouichi , Hayashi Toshio , Yamakawa Hiroyuki
Published: November 2005

Homoepitaxial Si growth by photochemical vapor deposition (photo-CVD) of Si2H6 using vacuum ultraviolet (VUV) light from a microwave-excited D2 lamp has been investigated. Epitaxial Si films can be obtained by this method at a growth temperature of 650°C, which is much lower than that used in conventional thermal CVD. A surface cleaning method of Si substrates by VUV light irradiation has been proposed. It was found from AES and RHEED studies that light irradiation prior to film growth is effective for the elimination of oxide and carbon contaminants on the substrate. Crystalline quality of grown films and dissociation mechanism of Si2H6 by VUV light are also described.
Growth of YBa2Cu3O9-δ Single Crystals from the High Temperature Solution
Authors: Hayashi Shigeyuki , Komatsu Hiroshi , Inoue Tetsuo , Ōno Takashi , Sasaki Koh , Koike Yoji , Fukase Tetsuo
Published: November 2005

YBa2Cu3O9-δ single crystals in the shape of a needle and a square plate were grown from a CuO-rich solution at a high temperature. The maximum size of the platy crystals with superconductivity was about 1.5×1×0.2 mm3. The details of the growth procedures of the single crystals are reported here.
MBE Growth of Ga1-xInxAs Alloy on Si Substrate
Authors: Oe Kunishige , Takeuchi Hiroaki
Published: November 2005

Ga1-x
In
x
As ternary alloy layers were successfully grown on Si substrates by molecular beam epitaxy for the first time. Layer characterization by RHEED, X-ray diffraction and room temperature photoluminescence reveal that single domain Ga1-x
In
x
As alloys which cover the 1.2∼1.6 µm wavelength region can be grown by a two-step growth method.
High-Tc Superconductivity of La-Ba-Cu Oxides. II. –Specification of the Superconducting Phase
Authors: Takagi Hidenori , Uchida Shin-ichi , Kitazawa Koichi , Tanaka Shoji
Published: November 2005

Occurrence of high-T
c superconductivity with T
c near 30 K is observed for the single phase of (La·Ba)2CuO4-y
by both magnetic susceptibility and resistivity measurements. This indicates that high-T
c superconductivity in La-Ba-Cu oxide is realized in the K2NiF4-type structure, (La·Ba)2CuO4-y
.
Structure of the High Tc Superconductor, Ba2LaCu3-xO7-y –Studies on La-Ba Ordering and Oxygen Defects
Authors: Nakai Izumi , Imai Katsuhiro , Kawashima Takuji , Yoshizaki Ryozo
Published: November 2005

Crystal structures of semiconductor Ba2LaCu3-x
O7-y
sample and 56.5 K superconductor sample, which was obtained by annealing the former in O2, were determined by X-ray Rietveld analysis. The ordering of Ba and La has been clarified by the use of the anomalous dispersion effects. An increase in the site occupancy factor of square planer oxygen (O(2):at z=0) around Cu(1) and shortening of Ba-O(2) distance were observed in the high T
c sample compared with the semiconductor. This oxygen behavior, i.e. formation of fully occupied square planer oxygen group (O(1)×2+O(2)×2) around Cu(1), determines the appearance of the superconductivity.
Defect Structures in InP Crystals by Laser Scanning Tomography
Authors: Fillard J. P. , Gall P. , Baroudi A. , George A. , Bonnafe J.
Published: November 2005

Laser-beam scanning tomography images are taken from various InP crystals. They all display a distribution of bright points which are shown to be statistically arranged along the crystallographic axes <100> and <110>. These microdefects are likely distributed along dislocations in such a way that small volumes or “cells” (typically 200-500 µm wide) are kept free from defects. It is shown that the density of defects varies with the doping of the material; lower densities were observed in Fe-doped InP crystals.
High-Field Faraday Effect of Tb-Doped Glass Above Paramagnetic Saturation
Authors: Chiba Yoshiaki , Hori Hidenobu , Yonenobu Kenji , Yamagishi Akio , Date Muneyuki
Published: November 2005

High-field Faraday effect is investigated in Tb-doped glass under a pulsed high magnetic field up to 40 tesla(T). The nonlinear Faraday effect due to saturation of the paramagnetic moment appears below about 20 T at 4.2 K. A considerably large Faraday rotation with the Verdet constant of -45.0 rad. T-1 m-1 is found above the paramagnetic saturation field, and this is explained by the field-induced level mixing in the multiplet levels.
A Scanning X-Ray Fluorescence Microprobe with Synchrotron Radiation
Authors: Gohshi Yohichi , Aoki Sadao , Iida Atsuo , Hayakawa Shinjiro , Yamaji Hironao , Sakurai Kenji
Published: November 2005

A scanning X-ray fluorescence (XRF) microprobe using Wolter type 1 optics was developed, and two-dimensional XRF measurements were carried out using synchrotron radiation up to 10 keV as an excitation source. The system of this microprobe and the results of two-dimensional measurements of a resolution check pattern and rock samples are described. The estimated spatial resolution was better than 10 µm.
Crystalline Phases in Superconductor Ba-Y-Cu-O with High Tc Prepared by Melting Method
Authors: Komatsu Takayuki , Imai Kouji , Matusita Kazumasa , Ishii Mamoru , Takata Masasuke , Yamashita Tsutomu
Published: November 2005

A superconducting Ba-Y-Cu-O oxide with high T
c was prepared by a melt quenching method, and the effect of melt quenching conditions on the value of T
c and crystalline phases in quenched and annealed samples was examined. It was found that the values of T
c,zero for annealed samples were 88 or 89 K, irrespective of the first melt quenching conditions. The crystalline phases in quenched samples were a mixture of Y2O3 and BaCuO2, and the main crystalline phase in annealed samples was orthorhombic Ba2YCu3O7-δ Superconducting Ba2YCu3O7-δ oxides were formed very easily by annealing the melt quenched samples.
Optical Multiple-Valued Logic Gates: Complement and Literals
Authors: Mada Hitoshi , Ozawa Takao
Published: November 2005

Complement and literal gates of multiple-valued logic have been implemented optically. These gates are composed of basic optical devices which are multithreshold, linear inverter, and variable thresholding. A liquid crystal light modulator and an electric feedback system realize the basic devices. In these devices, a direction of linear polarization of light is employed for representation of an optical signal strength.
Electrical Properties of YBa2Cu3Oy at High Temperatures
Authors: Munakata Fumio , Shinohara Kazuhiko , Kanesaka Hiroyuki , Hirosaki Naoto , Okada Akira , Yamanaka Mitsugu
Published: November 2005

Electrical resistance of YBa2Cu3O
y
(YBC) was measured from room temperature to 1123 K while varying oxygen partial presure. Electrical conduction mechanism in YBC changed from metallic to semiconductive around 700 K in air. Oxygen deficiency associated with temperature and oxygen partial pressure of the ambience dominated the electrical conduction mechanism.
High Tc Superconductor Prepared by Oxidization of a Liquid-Quenched Yb1Ba2Cu3 Alloy Foil in Air
Authors: Matsuzaki Kunio , Inoue Akihisa , Kimura Hisamichi , Aoki Kiyoshi , Masumoto Tsuyoshi
Published: November 2005

An Yb1Ba2Cu3 alloy foil with a nonequilibrium structure including an amorphous phase was prepared by splat-quenching. Heating of the alloy foil in air resulted in the structural change to a crystalline metallic phase at about 490 K, followed by the oxide formation of Yb1Ba2Cu3O6.8 at temperatures above about 540 K. The Yb1Ba2Cu3O6.8 prepared by oxidization of the liquid-quenched alloy foil was found to exhibit high T
c superconductivity with onset at 91 K and zero resistance at 85 K, even though the J
c value at 4.2 K was as low as about 1.9 A/cm2 in the absence of applied field and 0.4 A/cm2 at H=7 T.
Preparation and Magneto-Optical Kerr Effect of PtMnSb/NiMnSb Multilayer Films
Authors: Takanashi Kōki , Fujimori Hiroyasu , Shoji Masuhiro , Nagai Aisaku
Published: November 2005

We prepared PtMnSb/NiMnSb multilayer films using a dual-type rf magnetron sputtering method. The multilayer period was designed in the range from 20 Å to 200 Å. The X-ray diffraction data showed the existence of compositional and structural modulations. [111] texture of the Clb-type structure with a preferred orientation normal to the film plane was found. The satellite peaks due to the multilayer periodicity appeared around the [111] peak, and the peak intensities were explained from a step model. The Kerr rotation angles at 633 nm wavelength decreased with decreasing multilayer period.