bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior of Air Bubble Attaching to a Point Electrode in Liquid Dielectrics
Authors: Arii Kiyomitsu , Kitani Isamu
Published: November 2005

Using a new technique which was able to attach a bubble to a point electrode, the behavior of a bubble in insulating liquids (silicone oil and hexane) was investigated under a negative point condition. Above a threshold voltage, successive pulsed discharges were produced in the bubble; these were very similar to Trichel corna in gases. The interval of the pulse was almost constant at a certain voltage, but decreased with increasing applied voltage. The discharge could induce a mechanical vibration with a frequency that was much higher than that of the discharge pulse. The vibration might be sustained by a pressure change in the bubble or a small displacement of liquid inside a fine insulating pipe for suppling the bubble.
A Micro-Quantitative AES Analysis Using SEM-SAM Apparatus (Applied to Ag/Si Interfaces on Si(111) and Si(100) Surfaces)
Authors: Tokutaka Heizo , Nishimori Katsumi , Ishihara Naganori , Seki Toshinori
Published: November 2005

Two kinds of samples were prepared in order to analyze the Ag/Si interfaces on Si (111) and Si (100) surfaces. Type 1: Ag films were deposited on Si (111) and Si (100) at higher substrate temperatures (300∼400°C). Type 2: Ag films were first deposited on Si (111) and Si (100) substrates at room temperature and heat treated thereafter at higher substrate temperatures (300∼400°C). These prepared samples were observed using high-resolution scanning electron microscope and scanning Auger electron microscope (SEM-SAM) equipment. Then, the Auger electron spectroscopy (AES) data from a micro-point analysis were analyzed by a newly developed quantitative AES method. The results show that about one monolayer of Ag grows on both the Si (111) and Si (100) surfaces and Ag islands grow thereafter (Stranski-Krastanov mode). Further, an averaged Ag island size near saturation was about 1 µm on Si (100) and its density was about 10-times larger than that on Si (111).
Measurements of Hydrogen Atom Density in a Z-Discharge Plasma Using Intensities of Hα and Hβ Lines
Authors: Suzuki Hiroshi , Nobata Kanehiro
Published: November 2005

A study is presented on the time evolutions and radial profiles of the hydrogen atom density in a Z-discharge without pinched states. The time evolutions of the hydrogen atom density n
H were experimentally determined from the ratio of the chord-averaged intensity of the Hα line to that of the Hβ line. The two line intensities were simultaneously measured by splitting a collimated radiation beam from the same position into two beams. The hydrogen atom density evaluated from the intensity ratio was sufficiently low under conditions of a high discharge current. For a pressure of 20 mTorr, the magnitude of the density reached 0.1×1014 cm-3 at a time 50 µs after the initiation of the Z-discharge. The radial profiles of n
H, obtained from the chord-averaged intensities of Hα line, showed an annular-type distribution.
High Pressure Reactive Ion Etching of P-Doped Polysilicon with HCl
Authors: Tsou L. Y.
Published: November 2005

Reactive ion etching of the P-doped polysilicon with high pressure HCl was extensively investigated in a single wafer etcher. Despite the high pressure, anisotropic etch was accomplished along with the high etch rate. Extremely high selectivity with respect to the gate oxide was achieved for the sample patterned without photoresist. Carbon-containing species produced by the reaction of the photoresist with the chlorinated plasma was identified and was suspected to be responsible for the enhanced oxide etch rate for samples with photoresist. An optical multichannel end point detector was also described.
The Density Gradient of Multiplied Dislocations in the Surface Region of Deformed Sn Crystals
Authors: Fujiwara Masami , Hirokawa Tomoo
Published: November 2005

When a Sn crystal was plastically deformed in tension, a hard layer of high dislocation density was formed in the near-surface region, extending to 0∼150 µm in depth below the surface. The hard layer involved a plateau region of constant dislocation density with a depth of 30∼100 µm. The presence of such a plateau region suggests that both the surface and the interior dislocation sources are already activated at an early stage of plastic deformation.
Growth and Superconductivity of Nb5Sn2Ga Crystals
Authors: Shishido Toetsu , Toyota Naoki , Takei Humihiko
Published: November 2005

An Nb5Sn2Ga single crystal was grown for the first time from the melt of Nb, Sn and Ga by a slow cooling method. The crystal structure was tetragonal (space group D4h
18-I4/mcm) and isostructural with Nb5Sn2Si. This material exhibited superconductivity at T
c = 1.75 K.
Fluorescence from Pearls under N2 Laser Excitation and Its Application to Distinction of Mother Oysters
Authors: Miyoshi Tadaki , Matsuda Yasunori , Komatsu Hiroshi
Published: November 2005

Fluorescence spectra of pearls of Pinctada fucata (Japan's Akoya oyster) and Pinctada maxima (white 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 the difference in the fluorescence spectra under N2 laser excitation.
Cathodoluminescence Study on Diffusion Coefficients of Al, Ga and In in ZnSe
Authors: Takenoshita Hiroshi , Kido Kazutaka , Sawai Katsunori
Published: November 2005

The temperature dependence on the diffusion coefficients of Al, Ga and In in ZnSe was studied. The cleavage cross-sectional surface of a diffused ZnSe wafer was observed by the cathodoluminescence mode of SEM. The following relations were obtained: D
Al=1.18×10-1 exp
(-1.92 eV/k
T), D
Ga=6.76×10-2 exp
(-1.80 eV/k
T) and D
In=4.45×10-1 exp
(-1.84 eV/k
T).
The Radial Distribution Function of a Tb21Fe79 Amorphous Film
Authors: Fukuda Kazuo , Katayama Shinya , Katayama Toshikazu , Nukui Akihiko , Makisima Akio
Published: November 2005

The inter-atomic distances and the coordination number of a Tb21Fe79 amorphous film were obtained by a X-ray radial distribution function analysis. The nearest-neighbor distances are close to the sum of the metallic radii. The local structure is nearly the same as that of Gd18Co82 in spite of the differences in constitutional elements; also, the Fe-Fe coordination number depends upon the composition. These observations support the binary Dense Random Packing of Hard-Spheres model.
Computer Simulation for Diffusion and Two-Phase Equilibrium in Heterojunction
Authors: Tsujimoto Tokuzou
Published: November 2005

Structural changes occurring in heterojunctions with lapse of time are treated as the behavior of thin-film diffusion couples, and the Cahn-Hilliard non-linear diffusion equation is solved without omission for such couples for the first time. It is shown that two phases in equilibrium connected by a diffuse interface are formed at temperatures where the two phases are immiscible. Effects of thickness in the couples and of the gradient energy coefficient on the composition difference between the two equilibrium phases are determined. The formation of the asymmetric composition profiles yielded by the non-linear term and the rapid disappearance of the initial sharp interface as a result of the gradient energy are also analysed.
A New Switching Effect in Semi-Insulating GaAs and Its Use for Deep Level Spectroscopy
Authors: Yamashita Akiyasu , Osada Yoshihiro
Published: November 2005

Transient photocurrents of semi-insulating GaAs crystals were studied in the spectral range 0.5-3.0 µm as a function of the applied voltage. Measurements were made using rectangular pulses and diode structures with transparent electrolyte contacts. It was found that a new switching effect occurs at high electric fields (above 4×103V/cm) from a semi-insulating state to a conducting state. This effect is very sensitive to extrinsic light and has two characteristic times (a delay time and a decay time of the conducting state). A mechanism for these results is proposed on the basis of a multi-level model of impact ionization of deep levels. Typical spectra of the peak photocurrents are also presented. From these spectra twelve energy levels were obtained and compared with published data regarding deep levels in GaAs.
Schottky Contacts on n-InP Surface Treated by Plasma-Induced Oxygen Radicals
Authors: Yamagishi Haruo
Published: November 2005

An Au/n-InP Schottky contact formation on an InP surface exposed to plasma-induced oxygen radicals and its electrical characteristics have been investigated. Auger electron spectroscopy (AES) measurements revealed the presence of oxygen atoms at the Au/InP interface, indicating an oxide-layer formation. The Schottky contacts showed an ideality factor n of about 1.06 and an enhanced barrier height φB0 of about 0.7 eV, quite stable for annealing temperatures up to about 300°C. We observed a large decrease in the reverse leakage current, three orders of magnitude smaller than that of conventional Au/n-InP contacts. A barrier-height increase of about 0.2 eV could be interpreted on the bases of an inter-facial-layer model.
Basic Characteristics of Gas Tunnel Type Plasma Jet Torch
Authors: Arata Yoshiaki , Kobayashi Akira , Habara Yasuhiro
Published: November 2005

The basic characteristics of a gas-tunnel type plasma-jet torch has been experimentally investigated. The pressure along the central axis of the gas tunnel could be reduced to a very low value. The plasma jet produced in this low-pressure gas tunnel was longer than a conventionally produced jet, and had a positive volt-ampere characteristic. The potential gradient reached more than 40 V/cm and the energy density was estimated to be more than 106 W/cm2.
Piezoresistive Effect of Hydrogenated Microcrystalline Silicon Prepared by Plasma- and Photo-Chemical Vapor Deposition
Authors: Nishida Shoji , Konagai Makoto , Takahashi Kiyoshi
Published: November 2005

The piezoresistive effect of hydrogenated microcrystalline silicon (µc-Si: H) prepared by plasma- and photo-chemical vapor deposition (CVD) was measured, and the stability of µc-Si: H on the gauge factor was studied. The gauge factors of doped µc-Si: H prepared by plasma-CVD were found to be -25 ∼ -40 and 16∼23 for n- and p-type, respectively. As the rf power during the preparation was increased, the measured gauge factor increased for both n- and p-type. The photolysis process was also used to deposit highly conductive µc-Si: H films, and the gauge factor of the films was improved to -61 for n-type and 43 for p-type. A degradation of the gauge factor was observed when the films prepared by both processes were annealed, but the resulting gauge factor for the photo-CVD films was still larger after 8 hours' annealing.
A DC-Gas Discharge Display Device for Data Information Systems
Authors: Okamoto Yukio , Shinada Shinichi , Kougami Akihiko , Fukushima Masakazu
Published: November 2005

A very simple flat display device is presented for data information systems. This device has a self-scanning function achieved through a dc gas-discharge. The display panel for this device consists of two glass plates; anodes are formed on one plate and a black film and cathodes on the other. The anodes and cathodes are perpendicular to each other and are separated by the barriers formed in parallel between the anodes. All fabrication steps are performed by using screen-printing technology. The cathodes are connected to 32 busses and a time serial 32-phase pulse voltage is applied. Conversely, continuous scan and display pulse voltages are applied for a self-scanning operation and an information dispaly, respectively, to each anode.
Ion-Clearing System of UVSOR Storage Ring
Authors: Kasuga Toshio
Published: November 2005

An ion-clearing system consisting of DC and RF electrodes was installed to cure an ion-trapping effect in the UVSOR, a 600-MeV electron storage ring. In experimental studies of their effectiveness, it was found that the simultaneous use of both electrodes is essential for clearing ions.
Production of 35 keV, 1 A Steady-State Ion Beam
Authors: Nihei Hitoshi , Morikawa Junji , Ishida Shinichi , Inoue Nobuyuki , Ota Kanji , Uchida Taijiro
Published: November 2005

A hydrogen ion beam, (35 keV, 1 A) was extracted for 1 hour from a modified duoPIGatron ion source. The extraction grids and the plasma source were effectively cooled and the steady-state beam was extracted. When the arc plasma current was controlled by the feedback signal from the accel current, a sufficiently stable ion beam was extracted for 1 hour from 2 ms after the ignition of arc plasma. The stability of the ion beam power and the divergence angle were both less than ±0.5%.
A Simple Conversion System of Energy From Light to Mechanical Rotation: A Photomotor
Authors: Aoki Takashi
Published: November 2005

A photomotor which can convert light into mechanical rotation energy with the use of air molecules has been designed, and dependences on rotational frequencies, torques and axial powers, blade angles, illumination intensities and a stator structure have been investigated. The axial power has been found to be proportional to the third power of the rotational frequency and proportional to the 1.74th power of radiation energy. The conversion efficiency increased as the 0.74th power of the increasing radiation energy. The theoretical efficiency was calculated to be 7.0×10-3%, while the experimental efficiency has reached 3.0×10-3% at a radiation energy density of 22.5 mW/cm2. The photomotor can be characterized as a heat engine using extremely low-grade heat.
Ion-Induced Anger Electrons Emitted from MgO and GaP under Shadowing Conditions
Authors: Kudo Hiroshi , Shima Kunihiro , Takita Kôki , Masuda Kohzoh , Murakami Kouichi , Itoh Hisayoshi , Ippōshi Takashi , Seki Seiji
Published: November 2005

By using single-crystal targets of MgO and GaP, we have measured the energy-degradation spectra of K-shell Auger electrons induced from Mg and P by twenty-MeV He++ ions. The spectra measured under ion-beam shadowing conditions were interpreted through a modified model in which multiple angular deflection of Auger electrons is taken into account. From the analysis, the stopping power for 1.18-keV electrons in MgO was determined to be 2.10±0.21 eV/Å, and that for 1.86-keV electrons in GaP was determined to be 1.60±0.15 eV/Å.
High Energy Electron Diffraction Study on Ionic Character of Amorphous SiO2
Authors: Ohsaki Hisashi , Tada Masato
Published: November 2005

The structure of amorphous SiO2 film prepared by electron-beam evaporation has been investigated. The structural parameters of the shortest Si-O, O-O and Si-Si atomic pairs were determined from the radial distribution function by the least-squares method. Regarding the structural analysis of the evaporated amorphous SiO2 (ev.a-SiO2), the scattering factors for neutral and ionized atoms were used in order to investigate the ionic character of SiO2. The obtained values for each atomic distance did not vary with the scattering factors used, but the obtained number of each atomic pair was greatly dependent on the factors. From the results of the structural parameters, it was found that ev.a-SiO2 is constructed from basic silicate tetrahadrons, and that the constituent silicon and oxygen atoms have some ionic character.
Raman Scattering Studies in a-SiH Films Grown with Columnar Morphology
Authors: Kshirsagar S. T. , Khaladkar N. R. , Mamdapurkar J. B. , Sinha A. P. B.
Published: November 2005

The nature of columnar growth and short range order in a-Si:H films has been studied as a function of thickness using Raman scattering. The films have been prepared by glow-discharge dissociation of silane diluted in argon and using high rf powers. The TO-bandwidth in the Raman spectra has been used as a measure of the order in the amorphous phase. Thicker films deposited using 20% or more of silane yielded Raman spectra similar to those of hydrogen-rich amorphous silicon alloys. Raman spectra of thinner films were similar in structure to those of rf sputter deposited pure a-Si films. Films grown under identical conditions exhibit thickness dependent improvement in the short range order in amorphous phase. The TO-bandwidth decreases rapidly with increasing thickness and then becomes constant at a threshold thickness, t
s. With decreasing silane concentration (σ), the t
s value is first found to decrease, reaches a minimum at 7% and then abruptly increases near σ=3.5%. These results are explained in terms of variation of compressive stress in the film as a function of silane dilution.
Preparation and Properties of a-SiGe:H:F Films by a Glow Discharge Decomposition
Authors: Tsuda Shinya , Tarui Hisaki , Haku Hisao , Dohjo Hiroshi , Watanabe Kaneo , Hishikawa Yoshihiro , Nakamura Noboru , Nakashima Yukio , Takahama Tsuyoshi , Nishiwaki Hidenori , Fukatsu Takeo , Nakayama Shoichiro , Ohnishi Michitoshi , Nakano Shoichi , Kuwano Yukinori
Published: November 2005

As a high quality narrow bandgap material, hydrogenated and fluorinated amorphous silicon germanium (a-SiGe:H:F) by a glow discharge decomposition of SiF4+GeF4+H2 was systematically investigated. Microcrystalline (µc) Ge was found to be obtained when the GeF4 gas flow ratio is high, and µc-Si can be observed when the substrate temperature is high. These results indicate a strong influence of the formation of microcrystalline structures on film properties. More than 107 rectification ratio was obtained for a-SiGe:H:F Schottky diodes at a bias voltage of 1 V. The collection efficiency at the wavelength of 800 nm was improved to 32% with p-SiC:H (hydrogenated amorphous silicon carbide)/i-SiGe:H:F/n-Si:H(hydrogenated amorphous silicon) diodes.
Iron Ions in ZrF4-Based Fluoride Glasses
Authors: Nakai Tetsuya , Mimura Yoshinori , Shinbori Osamu , Tokiwa Hideharu
Published: November 2005

Mössbauer spectroscopy, magnetic susceptibility and optical absorption studies have been carried out in order to investigate the states of iron ions in ZrF4-based fluoride glasses prepared using oxidising (NF3 and O2) and inert (Ar) atmospheres. Under oxidising atmospheres iron ions are present as high-spin ferric ions in an octahedral field, while under an inert atmosphere they are in high-spin ferrous states, occupying two inequivalent octahedral sites.
In addition, the behavior of ferric ions under the inert atmosphere has been investigated. Ferric-ion stably exists in Ar, but with the presence of moisture they react with OH and are accordingly reduced to ferrous ions.
Electronic State and Glow Discharge Decomposition of Tetramethyldisilane
Authors: Koinuma Hideomi , Funabashi Makoto , Kishio Kohji , Kawasaki Masashi , Hirano Tsuneo , Fueki Kazuo
Published: November 2005

Tetramethyldisilane, a new source gas for amorphous silicon carbide, was decomposed by an rf glow discharge. Its reactivity in the formation of amorphous films was higher than a mixture of monosilane and methane gases. A plasma diagnosis by optical emission spectroscopy was contrastive between the two source gas systems, being consistent with the bond energy of the gases determined by a semi-empirical molecular orbital calculation. Judging from the rf power and the substrate temperature dependences on the optical band gaps of the films, the films prepared from tetramethyldisilane have optical band gaps wider than 2.2 eV and their structures appear to be different from those prepared from a monosilane/methane (1/2) gas mixture under otherwise the same conditions. Carbon and silicon atoms are apparently distributed more homogeneously in the former films than in the latter films.
One-Dimensional Antiphase Domain Structures in the Aluminum-Rich Al-Ti Alloys
Authors: Miida Rokuro
Published: November 2005

One-dimensional antiphase structures with average domain sizes of non-integral multiples (M=1.33-1.91) of the basic Ll2 cell, existing in the Al3-x
Ti1+x
(0<x<1/3), have been studied by high-resolution electron microscopy and X-ray powder diffraction. The mixing mode of M=1 and M=2 domains is revealed and the nature of lattice modulation associated with an antiphase structure is clarified. Ti atoms and Al-rich “statistical” atoms bordering on the antiphase boundaries are displaced away from and towards the boundary, respectively. The amounts of displacement are estimated on the basis of X-ray intensities. It is revealed that the Al2Ti appearing in the Al3-x
Ti1+x
contains a small amount of Ga2Zr-type modification in the form of faulted zones within a matrix Ga2Hf-type structure. The nature of displacement modulation existing in the stoichiometric Al2Ti is also clarified.
Preparation and Electrical Properties of CdSb Thin Films
Authors: Kashiwaba Yasube , Ohya Nobuhiro , Ikeda Toshio
Published: November 2005

A method for preparing intermetallic compound CdSb films with p-type conduction and their electrical properties are described. Films with CdSb crystallites were prepared by two methods: (1) by annealing as-deposited amorphous Cd-Sb films with a low content of Cd and (2) by annealing as-deposited polycrystalline films with CdSb, Cd3Sb2, Cd, and Sb crystallites. In the former case, the CdSb films were grown in a [100] preferred orientation and were characterized by a low carrier concentration. In the latter case, the CdSb films had a random orientation of crystallites and could be characterized by a large Seebeck coefficient. In that case, both the Seebeck coefficient and the thermoelectric figure of merit had almost the same values as those of a CdSb single crystal.
Far-Infrared Optical Properties of Quenched Germanium. IV. Uniaxial Stress Effects on the SA2 Acceptor
Authors: Hattori Takeshi , Tanaka Tsuyoshi , Mitsuishi Akiyoshi , Kamiura Yoichi
Published: November 2005

Far-infrared absorption spectra of quenched germanium were measured under a uniaxial compressive force along the <100>, <110> and <111> crystallographic orientations. It has been concluded from analyses of the number of the bands split with stress and from the feature of the splitting of each band that the SA2 acceptor, which is one of the quenched-in acceptors and whose ground state is split into two levels without the external fields, is constructed from a defect whose symmetric axis is along the <111> crystallographic axis. The energy levels of the SA2 acceptor with stress are discussed; then, the deformation potential constants of the ground state of this acceptor and the valence band are estimated and are compared with those from about group-III-element acceptors.
Injection-Locked Mode-Beating in TEA CO2 Laser as a High-Power Modulation Method
Authors: Sun Ke-Xun , Nagatsu Masaaki , Tsukishima Takashige
Published: November 2005

Injection-locked mode-beating is suggested as a high-power, high-frequency modulation method for a ponderomotive source in driven-scattering plasma diagnostics. Results of a proof-of-principle experiment are reported. Mode-beating involving two or more modes, as well as their evolution, were observed for various cavity lengths of an injection-locked TEA CO2 laser.
Ellipsometric Studies on Plasma-Oxidation Process of Iridium-Carbon Composite Films
Authors: Sato Yoshiyuki
Published: November 2005

The plasma oxidation of Ir-C films has been investigated using ellipsometry and XPS (X-ray photoelectron spectroscopy). The XPS measurements show that the concentration of C atoms in the Ir-C film is greatly decreased by plasma oxidation, suggesting that selective sputtering of C atoms from the Ir-C film makes the film porous and facilitates its oxidation. A quantitative analysis of the ellipsometric measurements at a wavelength of 633 nm shows that the refractive index, extinction coefficient and steady-state thickness of the oxide films lie in the ranges 1.5±0.1, 0.2±0.1 and 50-110 nm, respectively. A voltammogram of the oxide film indicates that the electrochemical reactions taking place at the film-electrolyte (0.5 M H2SO4) interface are highly reversible.
Effect of Boundary Layer Thickness on the Photoluminescence Spectra of GaAs Grown by MOCVD
Authors: Sato Michio , Suzuki Motoyuki
Published: November 2005

Undoped GaAs epitaxial layers were grown by atmospheric MOCVD. The longitudinal distributions of photoluminescence spectra of these layers were studied. Mn, Cu, Si and C were found. The boundary layer thickness, which was expectd to develop on a heated substrate, showed no influence on the intensities of these metal impurities. The doping coefficient of the metal impurities may be unrelated to the boundary layer thickness. Where the boundary layer was thin, it was observed that a larger amount of carbon was incorporated in the epitaxial layers. Compared with a growth simulation, it is pointed out that the amount of the residual metalorganic gas which remained at the substrate surface is one of the significant factors regarding carbon incorporation.
Lattice Vibration of Thin-Layered AlAs-GaAs Superlattices
Authors: Toriyama Takeshi , Kobayashi Naoki , Horikoshi Yoshiji
Published: November 2005

This paper presents a theoretical investigation into the Raman spectra of the (AlAs)1(GaAs)1 and (AlAs)2(GaAs)2 superlattices using the normal coordinate treatment based on a rigid-ion model. The model involves a three-dimensional crystal lattice, long-range Coulomb interaction due to atomic ionicity, and the short-range interactions between neighbor atoms farther out. The results are compared with the observed Raman spectra of the (AlAs)1(GaAs)1 and (AlAs)2(GaAs)2 superlattices grown by flow-rate modulation epitaxy. Considering the interactions between the first, second and third nearest neighbors to be the short-range interactions, the experimental results are well reproduced by the theoretical calculations. Effective interactions are confirmed to exist between the Al and Ga atoms in the second nearest neighbors, and the Ga and As atoms in the third nearest neighbors.
Composition Effect on CV Profile and Threshold Voltage for MESFETs Fabricated in Undoped LEC SI GaAs
Authors: Yasuami Shigeru , Fukuta Katsuyoshi , Watanabe Masayuki , Nakanisi Takatosi
Published: November 2005

A correlation between substrate composition and electrical properties was investigated for undoped LEC SI GaAs crystals. The concentration of residual carbon in a crystal, acting as an acceptor, was found to decrease as the As content increased for As-rich crystals. Consequently, donors in n-active layers were less compensated for and the absolute value of the threshold voltage for MESFETs became higher as the As fraction increased.
Simulation of the Formation of Dust Grains in Space by a Plasma Jet Apparatus
Authors: Tanabé Toshihiko , Onaka Takashi , Kamijo Fumio , Sakata Akira , Wada Setsuko
Published: November 2005

Using a vacuum-tight plasma jet apparatus operated below one atmosphere, the condensation of solid particles in space was experimentally simulated. Atomized reactant gases consisting of Si, O, C, and H atoms generated in the plasma flame were injected into a reactor chamber filled with Ar gas of 200 Torr, and quenched into solid particles. The formed grains had irregular shapes and their sizes were smaller than 20 nm. X-ray diffraction patterns of the condensed grains showed no sharp peaks. It was found from IR absorption spectra that the particles contained C-H, Si-O, and Si-C bonds, irrespective of their initial abundances. These characteristics of the condensates were clearly different from those expected from equilibrium calculations.
Helical Type Kicker for Stochastic Momentum Cooling
Authors: Katayama Takeshi , Noda Akira , Tokuda Noboru , Yonehara Hiroto , Yoshizawa Morio
Published: November 2005

Stochastic momentum cooling has been performed for 7-MeV proton and 28-MeV α beams at TARN. In this experiment, a slow wave-type kicker with a helical inner conductor was used because the beam velocity was so small (0.12 the velocity of light). Its phase velocity was adjusted so as to be equal to the beam velocity in order to obtain a coherent signal propagation. In the present paper, theoretical formulations of the electro-magnetic field and of the dispersion relation are derived and the numerical results of shunt and transverse impedances are compared with experimental data.
Theoretical Considerations of a New Electronically Collimated Gamma Camera Utilizing Gas Scintillation
Authors: Fujieda Ichiro , Perez-Mendez Victor
Published: November 2005

A new electronically collimated gamma camera utilizing a gas scintillation position-sensitive detector and a multiwire proportional chamber is proposed and its imaging characteristics are discussed. The scheme preserves all the advantages of an electronically collimated system (ECS), i.e. high sensitivity and simultaneous multiple views of the object, over the conventional NaI gamma camera. Compared with the Ge-based ECS, this scheme gives a higher spatial resolution and avoids difficulties in constructing a large-area detector.
Mechanism of a High-Contrast Inorganic Ion Resist Using Amorphous WO3
Authors: Koshida Nobuyoshi , Tomita Osamu
Published: November 2005

Optical absorption spectra of thin amorphous WO3 films irradiated by a beam of sodium ions at ∼ 10 kV have been measured in order to determine the properties of these films as a negative-type ion resist. A characteristic color band of amorphous tungsten bronze was observed in a relatively low-dose region. The resist behavior at the threshold dose D
th was linked with the appearance of a metallic luster at the film surface and with a corresponding change in the spectral shape. The surface sodium content at D
th was nearly equal to the value at the insulator-metal transition of sodium tungsten bronze. The mechanism of this inorganic resist is based on a change in the chemical potential; this is mainly due to doping effects by ion implantation and partly due to some structural change by energy deposition.
Relation between the Direction of Whisker Growth and the Crystallographic Texture of Zinc Electroplate
Authors: Takemura Taketoshi , Kobayashi Masahiro , Okutani Masayuki , Kakeshita Tomoyuki , Shimizu Ken'ichi
Published: November 2005

The relation between the crystallographic texture of a zinc electroplate and the growth direction of a zinc whisker has been investigated. The growth direction of a zinc whisker on a zinc electroplate with a (101̄0) texture was <1000>.
Shock-Loading Effects on Superconducting and Ferromagnetic Transitions of ErRh4B4
Authors: Takeya Hiroyuki , Takei Humihiko , Koike Yoji , Fukase Tetsuo , Shishido Toetsu , Toyota Naoki , Syono Yasuhiko
Published: November 2005

Shock-loading effects on the superconducting and ferromagnetic transitions of ErRh4B4 are reported for the pressure range up to 90 GPa. The superconducting transition temperature T
c1 decreases with increasing shock-pressure, whereas the ferromagnetic transition temperature T
c2 increases. The pressure effect is discussed in terms of the residual strain by shock-loading.
New Far-Infrared Laser Lines from CH2Cl2 Optically Pumped by CO2 Laser
Authors: Ohkuma Haruo , Yamaguchi Shigeo
Published: November 2005

Two new far-infrared laser lines are reported in methylene chloride (CH2Cl2) optically pumped by a CO2 laser. One is the 194-µm line pumped by CO2 10 P(12) and the other is the 233-µm line pumped by 10 P(22). These laser lines may be due to transitions between rotational levels within the v
7 vibrational mode.
Fabrication of Planar Microlens by Transverse Electromigration Method
Authors: Sugiyama Hiroyuki , Kato Masayoshi , Misawa Shigeyoshi , Iga Kenichi
Published: November 2005

The fabrication of planar microlens by a transverse electromigration method has been proposed and demonstrated. The possibility of improving productivity has been obtained, while the optical properties of the resultant lens are almost equivalent to those observed by a conventional method. The N.A. and the focused spot diameter were 0.27 and 5.9 µm, respectively.
Studies on Dielectric Properties of Binary Mixtures of Butanols in Nonpolar Solvents–Linear Correlation Factor, Excess Molar Polarization and Excess Free Energy
Authors: Swain B. B. , Ray G. S.
Published: November 2005

Dielectric constant of binary mixtures of n-butanol, i-butanol and t-butanol in three nonpolar solvents namely benzene, carbon-tetrachloride and n-heptane have been measured at radio frequency. The linear correlation factor and excess molar polarization in these mixtures have been evaluated. Winkelmann-Quitzsch equation for binary mixtures9)has been used to calculate excess free energy in them. The results have been used to interpret the liquid structure in such mixtures.
Study of Slow Surface Waves in 70-GHz Solid-Plasma Waveguide Utilizing Maximum-Entropy Method
Authors: Kudo Michiaki , Obunai Tetsuo
Published: November 2005

The 70-GHz slow surface wave propagation characteristics in a transversely-magnetized partially-filled parallel-plate solid-plasma waveguide were studied by an interferometric method using n-type InSb at 77 K. Spectral analysis using the maximum-entropy method was applied to the interferometric patterns thus obtained. The results clearly indicate the existence of three different propagation modes, and their propgation constants were determined. One of these corresponds to the previously predicted slow surface wave mode, here confirmed experimentally for the first time. Surface wave resonance also takes place on this mode, and the maximum value of the phase constant, 5.5×103 m-1, was obtained. A relation between the estimated power density and the attenuation constant of these modes is suggested.
Focusing Characteristics of High-Efficiency Fresnel Zone Plate Fabricated by Deep Ultraviolet Lithography
Authors: Kodate Kashiko , Kamiya Takeshi , Okada Yoshiko , Takenaka Haruko
Published: November 2005

The feasibility of using photoresist Fresnel zone plates as micro-optic components was examined experimentally. Deep UV lithography was used to fabricate zone plates with submicron pitch, and nearly diffraction-limited spot formation and high efficiency were achieved. The direct collimation of a semiconductor laser beam was demonstrated.
Uniform Epitaxial Growth of Modulation-Doped GaAs/Ga0.7Al0.3As on Three-Inch Substrate by Metalorganic Chemical Vapor Deposition
Authors: Okamoto Akihiko , Terao Hiroshi , Kamejima Taibun
Published: November 2005

The uniform epitaxial growth of a modulation-doped structure on a three-inch substrate was achieved by low-pressure metalorganic chemical vapor deposition. The mobility of the structure at 77 K was between 61,000 and 71,000 cm2/(V.s), and the variation of the sheet carrier concentration was ±6.8% over the whole wafer except in the edge region of 5 mm. Furthermore, adjustment of the growth conditions gave an electron mobility as high as 322,000 cm2/(V.s) at 4.2 K. A horizontal reactor configuration with substrate rotation produces uniform growth with an abrupt interface on a large area.
Ferroelectric Domain Structure of X-Ray-Irradiated TGS
Authors: Nakatani Noriyuki
Published: November 2005

Domain patterns on the b-plane of X-ray-irradiated TGS crystals were examined by the rub etch method. The domain structure is not changed by the irradiation in the ferroelectric phase, and is reproduced after heat treatment. Crystals irradiated in the paraelectric phase show extremely fine domain patterns. The rate of evolution of the domain structure after heat treatment is reduced by the irradiation. These effects are explained by assuming that the microscopic defects formed by irradiation have polarity. The polarity of a defect is determined by the domain orientation at the defect site, and determines the direction of the bias field resulting from the defect.
Plasma Temperature Profile in the Boundary Layers of an MHD Channel
Authors: Aoki Yoshiaki , Seidou Tadashi , Imajyo Hidetsuka , Kitagawa Hiroki , Kayukawa Naoyuki , Yamazaki Hatsuo
Published: November 2005

The space-dependent plasma temperature in the boundary layer within the channel of an oil combustion MHD generator with externally-applied magnetic field installed at Hokkaido University was measured by a newly devised method using a light-polarization line-reversal technique. The measurement was performed at four hundred positions across the boundary layer during a period of 0.4 ms. The spatial distribution of temperature thus obtained indicated the 1/7- or 1/8-th power of temperature.
Supercooled Structure of Bismuth
Authors: Matsuno Naoshi , Kamiyama Hisao , Ishii Yoshinobu , Momiuchi Masayuki
Published: November 2005

The radial distribution function of supercooled bismuth was obtained as a function of temperature using the energy scanning X-ray method. The subsidiary maximum on the right-hand side of the first peak in RDF splits into two or three peaks as the temperature decreases. At the lowest supercooled temperature in the present experiment, a prominent pattern similar to that of pre-crystallization in amorphous films was observed. This technique is useful for structural analysis in the liquid state or the liquid-to-solid transition.
Electron Scattering by Impurities in Semiconductors
Authors: Otsuka Eizo
Published: November 2005

Electron scattering by various kinds of impurities in semiconductors was studied using millimeter wave and infrared cyclotron resonance, and it was found possible to use linewidth measurement to derive the inverse relaxation time of electrons due to impurities and hence the scattering coefficient as well as the cross section. The study ranged from well-identified impurity species in elemental semiconductors to more obscure ones in compound semiconductors, with both neutral and ionized impurity scattering being treated. The treatment was also extended briefly to dislocations and thermal defects. The results are tabulated for impurities in Ge and Si only, since they are basically extensible, mutatis mutandis, to impurity scattering in compound semiconductors.
The Structure of Glassy Carbon
Authors: Kodera Shiro , Minami Nobuyuki , Ino Tadashi
Published: November 2005

The structure of a glassy carbon made by Tokai Electrode Company has been studied by analyzing X-ray diffraction patterns from six types of sample subjected to different heat-treatments at temperatures from 700°C to 3,000°C. The diffraction intensity of AgKα1 radiation was measured to s = 22.1 Å-1 by the method of fluorescence excitation, and the theoretical diffraction intensity was calculated for stacks of turbostratic disks of circular cross section with diameters of 25 to 170Å and heights of 10 to 40Å. By comparison with the observed data, the mesh parameters and the size and number of stacking layers for each sample could be estimated on the assumption that the strain distribution in the sample is Gaussian and the standard deviation of the inter-atomic distance is linearly proportional to its mean distance.
Effects of Hydrogen Dilution of Silane on Properties of Glow-Discharged Undoped Hydrogenated Silicon
Authors: Shirafuji Junji , Nagata Shunsuke , Kuwagaki Mamoru
Published: November 2005

The electrical and photoelectronic properties of glow-discharged hydrogenated silicon films were measured as a function of the hydrogen-dilution ratio of silane. At low silane fractions SiH4/(SiH4+H2) below 10%, the formation of the so-called microcrystalline state was confirmed by X-ray diffraction analysis. However, the electron mobility measured by the time-to-flight method showed no drastic change after microcrystalline formation. The temperature dependence of the steady-state photoconductivity is quite different for samples in the amorphous (silane fraction > 10%) and microcrystalline (silane fraction < 10%) states, reflecting a difference in the recombination process. However, as far as the room-temperature photoconductivity is concerned, no great change is observed among samples deposited at different dilution ratios.
Far-Infrared Optical Properties of Quenched Germanium III. Effects of Additional Impurities
Authors: Hattori Takeshi , Tanaka Tsuyoshi , Mitsuishi Akiyoshi , Kamiura Yoichi
Published: November 2005

The far-infrared absorption spectra of quenched germanium containing Fe, Ni, Cu, Ag and Au were measured in order to study the effects of these additional impurities on the quenched-in acceptors, and it was found that these impurities perturb the quenched-in acceptors. Particularly, when the crystal was doped with Cu, Ag or Au impurities, only the absorption band series were observed in the wavenumber region around 50 cm-1 where the absorption bands due to the SA1 acceptor of pure quenched germanium were observed. These series were slightly shifted from the bands due to the normal SA1 acceptor. The absorption band series due to the SA1 acceptor were hardly observed in the sample containing Fe impurity, although the bands due to other quenched-in acceptors were observed. These facts seem to contradict the models for the SA1 acceptor proposed so far.
Measurement of Ballistic Mean-Free-Path of Hot Quasiparticles Injected in Superconductor-Base Hot-Electron Transistors
Authors: Kobayashi Takeshi , Sakai Hiroyuki , Kurita Yoshiyuki , Tonouchi Masayoshi , Okada Michihiro
Published: November 2005

A mean-free-path (L
B) measurement was made for hot quasiparticles injected into the Nb-base film of superconductor-base hot-electron transistors. The measurement was analogous to that used for a conventional hot-electron transistor, and gave L
B for the quasiparticles travelling in the direction normal to the Nb-base film surface. An L
B(4.2 K) value in excess of 1000 Å was attained for films thicker than 800 Å, whereas a marked reduction in L
B was seen in thin films, owing to the coarse crystalline quality of Nb film grown at the beginning of the sputter deposition.
Numerical Calculation of Magnetic Bubble Domain Wall Motion Based on a Lumped-Constant Model of Vertical Bloch Lines
Authors: Hayashi Nobuo , Nakatani Yoshinobu
Published: November 2005

An efficient way of calculating the motion of a domain wall which may contain a number of vertical Bloch lines has been developed on the basis of a previously constructed model in which the magnetization structure distributed in a Bloch line is regarded as being concentrated at a single point on the wall. It has been found that the equations of motion derived from the model can be solved in a stable manner by using the backward Euler method. The model has the same range of application as conventional models based on the so-called equation of wall motion. The results of computer simulation show that the method saves 95% of the computation time needed with the conventional method. This paper describes the derivation of the model and the principle of the numerical methods, together with the results of computer simulation clarifying the range of application of the model.
Magnetic Softness and Domain Wall Structures of Double-Layered Amorphous Co-Zr-Nb Films
Authors: Shimada Yutaka , Saito Nobuhiro
Published: November 2005

The magnetization process, domain wall structures and soft magnetic properties of amorphous Co-Zr-Nb double-layered films with various uniaxial anisotropies were investigated. Observation of the domain structure showed that intermediate SiO2 films formed by sputtering prevent direct exchange coupling between the magnetic films when their thicknesses are above 20 Å. A different magnetization process from those found in Permalloy multilayered films formed by evaporation was seen in the present amorphous films. The drastic improvement of the magnetic softness in double-layered films with very thin magnetic and nonmagnetic layers is useful for improving the recording density in perpendicular magnetic recording systems.
Electroreflectance and Photoluminescence Studies of In1-xGaxP1-yAsy Lattice-Matched to GaAs
Authors: Shirakata Sho , Kondo Masahiko , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

Electroreflectance measurements were performed on In1-x
Ga
x
P1-y
As
y
quaternary alloys grown on (100) GaAs by liquid-phase epitaxy in order to determine the precise band gap (E
0) and broadening parameter (Γ). It was found that the band gap energies obtained by photoluminescence measurements differ slightly from the precise energy gap determined by ER measurements. The broadening parameters in the ER spectra of In1-x
Ga
x
P0.7As0.3 LPE layers inside the miscibility gap of this alloy system are comparable with those of In1-x
Ga
x
P0.96As0.04 LPE layers, and hence the LPE growth is less affected by the immiscibility, suggesting that the extraordinarily broadened band-edge luminescence in In1-x
Ga
x
P0.7As0.3 is not due to the local distribution of the energy gap caused by the immiscibility. The effects of the immiscibility on the ER spectra are discussed in connection with the LPE growth conditions.
High-Rate Preparation of Amorphous-Silicon Solar Cells with Monosilane
Authors: Sichanugrist Porponth , Suzuki Hirohisa , Konagai Makoto , Takahashi Kiyoshi
Published: November 2005

Hydrogenated amorphous silicon (a-Si:H) films produced from monosilane (SiH4) at high deposition rates of 10-30 Å/s were studied. The p-i-n solar cells using these films as i-layers were fabricated with emphasis on the effect of light boron-doping during the i-layer deposition and the buffer i-layer at the p/i interface prepared at a lower deposition rate to minimize the interfacial damage from high-energy charged particles. By optimizing this buffer i-layer, a conversion efficiency of 9.1 % under AM1 (100/mW/cm2) illumination was obtained at a deposition rate of 10 Å/s. This high efficiency shows that the buffer i-layer at the p/i interface, prepared at a low deposition rate, is significant for the high-rate preparation of high-performance a-Si:H solar cells.
A Novel Method of Fabricating Te Thin-Film Transistors
Authors: Kawaguchi Takafumi , Tanaka Yasuharu , Sekiguchi Hiroshi , Hirai Hoko , Sato Katsuaki , Kobayashi Shunsuke
Published: November 2005

A new method of fabricating Te TFTs with high reproducibility is described. An adequate thickness of the Te layer appropriate to good transistor action was obtained by aging the evaporated TFTs at 70-80°C for several hours in normal atmosphere. The deposited Te films were characterized by measuring the temperature dependence of the conductivity, Hall mobility and ESCA. The results suggest that the aging process produces a layer of Te oxide on the surface and that the residual part is a semiconducting film of appropriate thickness, giving rise to the good transistor characteristics. After the aging, passivation by SiO
x
or Al2O3 evaporation was carried out, allowing the transistors to maintain operation for one year.
Evaluation of Synergism in Flashover Voltage Properties of Gas Mixtures
Authors: Okabe Shigemitsu , Kouno Teruya
Published: November 2005

The flashover voltage properties of gas mixtures have been investigated very actively over the past several years with a view to finding an alternative to SF6 as a dielectric gas. Almost all likely gas mixtures have been examined experimentally, and a systematic way of arranging the results is now being sought. The present paper evaluates synergism in the flashover voltage properties of binary gas mixtures consisting of SF6, N2, O2, Ar and CCl2F2 for each item caused by α and η (the ionization and attachment coefficients), and constituent gases. It is found that SF6+CCl2F2 and O2+N2 gas mixtures belong to the η-synergism group and the α-synergism group respectively, and α and η contribute in a similar degree in the other gas mixtures. It is also found that the constituent gases act on synergism in directions contrary to each other in almost all cases.
Spectroscopic Measurement of Electron Temperature during Lower Hybrid Current Startup in JIPP T-IIU Tokamak
Authors: Mimura Mikio , Sato Kuninori , Toi Kazuo , Fujita Junji
Published: November 2005

A simple diagram method is applied to obtain the time evolution of the electron temperature from the time history of the impurity line radiation which appears during the early phases of lower hybrid current startup in the JIPP T-IIU tokamak. This method makes it possible to survey the dependence of the time behavior of impurity emission on various plasma parameters (impurity influx rate, impurity confinement time, etc.). The electron temperature thus obtained agrees well with that derived from the temperature-sensitive line ratio and from Thomson scattering.