bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic Properties of Hydroxy Ni-Mica Intercalation
Authors: Takahashi Minoru , Sato Minoru , Ishio Shunji , Ohtsuka Kunio , Suda Mitsuru , Ono Mikiya
Published: November 2005

The magnetic properties of hydroxy Ni-mica intercalation complexes in which Ni forms two-dimensional lattices between mica layers have been investigated. The concentration of Ni was varied up to 21 wt%. The magnetic moment per Ni was evaluated from the Curie constants to be between 2 and 3 µB (dependent on the Ni content). Paramagnetic Curie temperatures obtained by the temperature dependence of the initial susceptibility are about 7-13 K for all the samples, while an apparent ferromagnetism is defined only for a sample with 2.6 wt% Ni by Arrott plots. These magnetic properties were explained by the formation of a Ni triad in a two-dimensional lattice because of the chemical stability of [Ni3(OH)5H2O]+ as an intercalant, and by a coaguration of triads with increasing Ni content.
Plasma Behavior in Reversed-Field Pinch Configuration
Authors: Hotta Eiki , Hidaka Kunihiko , Ohta Yutaka , Ko Kwang Cheol , Fuse Takashi , Hayashi Izumi
Published: November 2005

Helical deformations of a plasma column in a reversed field pinch experiment have been investigated using stereoscopic framing and/or streak photographs together with magnetic search-coils. A toroidal-mode number of 6 was found to be dominant in this experiment. This number agrees with the mode number predicted by a growth-rate calculation based on an ideal magnetohydrodynamic equation. It was observed that the plasma center moved around in a circular arc in the poloidal direction with a frequency of 100 kHz. Moreover, it could be seen that the displacement of the plasma center in the major radial direction traveled in a toroidal direction with a velocity of 0.9×104m/s.
Performance and Radiation Damage of a Lead/Scintillator Calorimeter
Authors: Saitoh Hitoshi , Murashita Masayuki , Tobimatsu Keijiro , Chiba Masami , Hirose Tachishige , Takasaki Fumihiko
Published: November 2005

The performance of a lead/scintillator electromagnetic shower calorimeter has been investigated for 0.5-3.0 GeV electrons and pions. The energy resolution (fwhm) for the electrons can be expressed by 0.38/E(GeV)1/2. The cross-section of the module is a trapezium with a height of 300 mm and the two parallel sides (19 and 113 mm) are read-out by two wavelength shifters. The position resolutions were 4-10 mm along the parallel sides and of 2.7-50 mm for the orthogonal direction with an assembly of the three modules. A dose of 1×104 Gy (1 Gy=100 rad) irradiation reduced the optical-attenuation lengths to 33 and 26% of those before irradiation for a plastic scintillator and the wavelength shifter, respectively.
Ohmic Heating in Rising Phase of Confining Field in Heliotron DR
Authors: Morimoto Shigeyuki , Kobayashi Sakuji , Iiyoshi Atsuo , Uo Koji
Published: November 2005

Ohmic heating which uses helical-vertical windings as a transformer was examined in Heliotron DR. This is a possible method for providing a high-density target plasma for further heating in Heliotron/Torsatron systems.
Photoconduction in Polyvinyl Carbazole Thin Films Polymerized by Plasma-CVD
Authors: Inoue Masumi , Morita Hiromasa , Takai Yoshiaki , Mizutani Teruyoshi , Ieda Masayuki
Published: November 2005

A study on the RF plasma-CVD of an organic photoconductor, polyvinyl carbazole (P-PVK), was carried out. The chemical structure of P-PVK was shown to be similar to that of the conventional PVK from IR and UV spectroscopic studies. The voltage dependence of the photocurrent was explained from the Onsager theory. The photovoltaic effect was observed when Al was used as an electrode. The power-conversion efficiency was estimated to be 3×10-3% for extremely thin P-PVK film (∼80 nm).
Effect of Alloy Composition in Liquid AuSi Ion Source
Authors: Komuro Masanori
Published: November 2005

The enrichment of the Si concentration on the needle surface of a liquid Au60Si40 (in at%) alloy ion source proceedes up to 80 at% during ion emission, resulting in fatting at the top region of the needle. The temperature dependences of the composition in the emitted ion fluxes show that the Si ion flux concentration varys proportionally to the composition of the liquidized alloy at the reservoir according to the phase diagram of an Au-Si system. At the same time, the ratio of Au++ to Au+ increases with a decrease in the Si concentration in the liquidized alloy, which shows an increase in the electric field strength at the ion-emitting site. It is shown that the Si enrichment is due to the precipitation of Si atoms in the liquidized alloy induced by a temperature difference between the reservoir and the top of a needle.
Deep Levels in GaAs Grown Using Superlattice Intermediate Layers on Si Substrates by MOCVD
Authors: Soga Tetsuo , Sakai Shiro , Umeno Masayoshi , Hattori Shuzo
Published: November 2005

Deep levels in MOCVD-grown GaAs using superlattice intermediate layers on Si substrates were investigated by DLTS. Electron traps at 0.44 and 0.73 eV were observed in the undoped n-type GaAs grown on (100)2° off Si substrates while only a 0.73-eV trap was detected in GaAs on a GaAs substrate. The deep-level concentration in GaAs/Si and the capture cross section of a 0.44-eV trap decreased and the half width of the 0.44-eV trap increased with increasing GaAs thickness. The 0.73-eV trap concentration increased upon decreasing the curvature radius of the wafer by polishing the back side of the Si substrate; however, that of 0.44 eV was unchanged. These observations suggest that the 0.44-eV trap is due to Si-defect complexes changing their shapes with the GaAs thickness and that of 0.73 eV is caused by point defects.
Magnetoresistance in Crystalline and Amorphous Fe-Co-Ni Based Alloys
Authors: Inagaki Matsumi , Suzuki Masayuki , Iwama Yoshiro , Mizutani Uichiro
Published: November 2005

The ferromagnetic anisotropy of electrical resistivity (FAR) has been measured at 300 and 77 K, together with the saturation magnetizationnB, the Curie temperature and the temperature coefficient of resistivity (TCR), for a large number of (Fe-Co-Ni)-X alloys in fcc, bcc and amorphous phases. Several empirical rules are presented. (1) The FAR is found to be correlated not only withnBbut also with the resistivity. In the low-resistivity regime the FAR reaches a maximum at aboutnB=1.0. The maximum becomes suppressed with increasing resistivity. In the high-resistivity regime, into which the amorphous alloys are grouped, the FAR increases monotonically with increasing magnetization. (2) The FAR value decreases rapidly with increasing resistivity. The value in the amorphous phase is one to two orders of magnitude smaller than that in the low-resistivity alloys. (3) Both FAR and TCR are closely interrelated; an increase in the FAR is always accompanied with an increase in TCR.
Molecular Orientation and Photoconduction of Polyimide
Authors: Iida Kazuo , Tanimoto Toshihiko , Nakamura Shuhei , Ieda Masayuki , Sawa Goro
Published: November 2005

The effect of the molecular orientation on photoconduction of polyimide was investigated. The anisotropy of the molecular chain alignment was observed by wide-angle X-ray diffraction. The photocurrents in three directions were measured. The in-plane photocurrents were anisotropic. As Kapton was drawn, the molecular chain had a tendency to arrange itself along the drawing direction and the in-plane photocurrent in the direction normal to the drawing direction was larger than that in the parallel direction. As the degree of intermolecular order decreased, the photocurrent in the normal to the film plane increased; however, the in-plane photocurrent decreased. It was concluded that the magnitude of the photocurrent is closely related to the molecular chain alignment and the orientation.
On the Equivalence of Ring and Pole-Keeper Head Fields
Authors: Huang Huei Li , Yen Sun Chung
Published: November 2005

The head field distributions for a conventional ring head and pole-keeper head are shown to be mathematically equivalent, provided that the head pole piece of the ring heads are large compared to the gap length and that the head-field Fourier coefficinets are properly redefined. Despite the equivalence, the ring head write fields are very dissimilar to those of the pole-keeper heads, either within the gap or outside of it in the trailing regions. A total of up to 200 Fourier coefficients was obtained for both heads for several values of the pole-thickness. As an application, the parameters related to the surface-gap field were also evaluated in order to facilitate write-field calculations.
Absorption Lines in the KrCl Laser Spectrum and the Spontaneous Emission of the Medium Related to KrCl
Authors: Shimauchi Midori , Miura Tokiwa , Oikawa Kenichi
Published: November 2005

A discharge-pumped KrCl laser and spontaneous emission spectra were investigated using a high-resolution grating spectrograph and two different type quartz-prism spectrographs. The high-resolution spectrum revealed strong absorption lines in the laser continuum, most of which could be assigned to the rotational lines of H35Cl bands of the B
1Σ-X
1Σ system. In the spontaneous-emission spectrum of the KrCl laser medium twelve peaks of the B-X system were observed; also the C-X and C-A systems of KrCl were identified through an analogy with other rare gas halides. To suppress HCl absorption lines the halogen donor, HCl, in the KrCl laser medium was replaced by Cl2. This replacement made the KrCl excimer unable to lase, while the HCl absorption was not weakened at all. The discharge became very bright around the cathode due to a strong continuum from UV to visible.
Excitation Anisotropy in Laser-Induced-Fluorescence Spectroscopy –High-Intensity, Broad-Line Excitation
Authors: Hirabayashi Atsumu , Nambu Yoshihiro , Fujimoto Takashi
Published: November 2005

The problem of excitation anisotropy in laser-induced-fluorescence spectroscopy (LIFS) was investigated for the intense excitation case under the broad-line condition. The depolarization coefficient for the fluorescence light was derived in the intense-excitation limit (linearly-polarized or unpolarized light excitation) and the results are presented in tables. In the region of intermediate intensity, between the weak and intense-excitation limits, the master equation was solved for a specific example of atomic transitions and its result is compared with experimental results.
Long-Term Stability of W-Ni MIM Diode as Difference Frequency Detector in the Infrared
Authors: Sakurai Toshio
Published: November 2005

Long-term mechanical and electrical stabilities of W-Ni point-contact diodes were investigated while being used as a difference frequency detector at CO2-laser frequencies. It was demonstrated that the typical life of such a diode is ten months with a signal-to-noise ratio of 50 dB.
XPS and AES Studies of Annealing Behavior of Carbon Adsorbed on Silicon Surfaces
Authors: Yokota Katsuhiro , Kimura Masatoshi , Kojima Kenji
Published: November 2005

Annealing Behavior of C atoms adsorbed on Si surfaces were studied by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). AES results showed that C atoms on the Si surfaces decreased with increasing annealing temperature. XPS results showed that the adsorbed C atoms diffused into Si during annealing and formed silicon carbide by combining with Si atoms.
Low-Temperature Thermal-Oxidation of Silicon
Authors: Uchida Yasutaka , Yue Jin-hai , Kamase Fumihiro , Suzuki Takayuki , Hattori Takeo , Matsumura Masakiyo
Published: November 2005

A native silicon-oxide layer has been thermally grown at 250°C by using a nitric and sulfuric acid mixture in a liquid phase under high-pressure conditions. It was found that the grown oxide layer was mainly of silicon-dioxide; however, the density of intermediate oxide was higher than that in a conventional and a thermally-grown oxide layer. The resistivity and the breakdown field strength of the oxide layer were more than 1014 Ω·cm and 4 MV/cm, respectively. The interface state density, evaluated from high-frequency C-V characteristics, showed a V-shaped distribution and its minimum value was about 1011/cm2eV.
Photoluminescence Decay Properties of Indium Doped ZnS
Authors: Zhou Jun , Goto Hideo , Sawaki Nobuhiko , Akasaki Isamu
Published: November 2005

The photoluminescence decay properties of indium-doped ZnS thin films grown epitaxially on (100) GaP were investigated. Three exponential components were found in the decay curves, of which the time constants were of the order of 1, 10 or 100 µs at room temperature. Upon increasing the In concentration, the time constants increased. By lowering the temperature the photoluminescence decay became faster, and at low temperatures the time constant was insensitive to the temperature. The results can be well described by the three-level model of Di Bartolo. It could be shown that the photoluminescence originated from the trapping-limited D-A pair emission, and that the decay properties are determined mainly by the non-radiative recombination probabilities which depend on the In concentration.
Behavior of a Plane Jet at Low Reynolds Number Confined in a Rectangular Channel II. Two Solutions by Numerical Analysis
Authors: Ouwa Yasuhiro , Watanabe Masaaki , Matsuoka Yoshihiro
Published: November 2005

Streamlines of confined symmetric and asymmetric channels at low Reynolds numbers were numerically analyzed by means of successive over-relaxation upwind schemes. Two different flow patterns were obtained for the same Reynolds number. These results gave examples in cases where the solution of the Navier-Stokes equation is not unique for the same Reynolds number. However, for a symmetric channel, one of these flow patterns with symmetry is unstable and makes a transition to the other asymmetric pattern.
Raman Spectroscopy and Dielectric Anomaly of Bi4Ti3O12
Authors: Ehara Shaw , Hattori Takeshi , Tanaka Junzo , Tsukioka Masayuki , Muramatsu Kunitaka , Shimazu Masaji
Published: November 2005

The Raman spectrum of a single crystal of Bi4Ti3O12 was studied with regard to its dielectric properties, The softening of any Raman band could not be observed below 80 cm-1 between room temperature and about 600°C; however, the intensities of some Raman bands were found to increase at around 500°C corresponding to a dielectric anomaly.
Alignment Controls and Switching Characteristics in a Ferroelectric Liquid Crystal with the Phase Sequence of N*-SC
*
Authors: Hatano Tomohiko , Yamamoto Kazunuki , Takezoe Hideo , Fukuda Atsuo
Published: November 2005

The switching characteristics in a SC
* ferroelectric liquid crystal with the N*-SC
* phase sequence, were studied. Two kinds of alignment methods were tried. The rubbing method gave a better alignment than the improved temperature gradient method. Although rubbing confines the molecular direction, the two possible layer directions could be altered by applying a DC electric field. The molecular switching between the up and down polarization states in the rubbing cell showed two characteristic asymmetric behaviors due to the strong monostable surface condition as follows. The response time from the stable to the unstable state was slower by a factor of several tens than that of the reverse process. The slow process was accompanied by the nucleation and growth of an unstable domain, while only a color change was observed in the fast process without any domain nucleation. It was also found that during this process surface molecules stayed unswitched.
Effect of Hydrogen Dilution of Silane in Hydrogenated Amorphous Silicon Films Prepared by Photochemical Vapor Deposition
Authors: Kamimura Takaaki , Hirose Masahiko
Published: November 2005

Hydrogenated amorphous silicon (a-Si:H) films were prepared by mercury photosensitized decomposition of silane-hydrogen (or-helium) gas mixtures. In hydrogen dilution, a-Si:H films were deposited from 20-100% of the silane fraction and hydrogenated amorphous-microcrystalline mixed-phase silicon (µc-Si:H) films were deposited for less than 10% of the silane fraction. The Si-H2 bond density and optical gap for a-Si:H films increased upon decreasing the silane fraction. The preferential orientation of the crystallites in µc-Si:H films was greatly changed by the silane fraction. However, the film characteristics did not change upon helium dilution. It was found that the hydrogen radical plays a significant role in the film-deposition process. Large-grain-size µc-Si:H films have been obtained, as compared with the grain size for films made by the conventional glow-discharge technique.
Hole Transport in a-Si:H(F) Prepared by Hydrogen-Radical-Assisted Chemical Vapor Deposition
Authors: Shibata Naoki , Miyauchi Akihiro , Tanabe Akihito , Hanna Jun-ichi , Oda Shunri , Shimizu Isamu
Published: November 2005

The modes of hole transport in both non-doped and BF3-doped a-Si:H(F) films prepared by hydrogen-radical-assisted chemical vapor deposition (HRCVD) were investigated by the time-of-flight method. Non-dispersive transport was observed at temperatures above approximately 300 K, and dispersive transport below this temperature. The drift mobility conforms with a multiple-trapping model which assumes that the valence-band tail is distributed exponentially in terms of energy. The characteristic temperatures provided by this model, 310 K for non-doped a-Si:H(F) and 286 K for a-Si:H(F) doped using 30 ppm of BF3, are lower than the corresponding value for a-Si:H films prepared by an R.F. glow discharge of SiH4. This result shows that the distribution of valence-band tail states is narrower in the case of HRCVD. Sub-bandgap profiles based on the wavelength dependence of photoconductivity also reveal a decrease in the density of mid-gap states.
Mössbauer Study of Fe-Zr Alloys Formed at Interfaces between Fe and Zr Thin Films
Authors: Harada Hisamochi , Ishibe Shoichi , Konishi Ryôsuke , Sasakura Hiroshi
Published: November 2005

The Mössbauer spectra of Zr films evaporated on Fe substrates (Zr/Fe) and Fe films on Zr substrates (Fe/Zr) were measured after heat treatments following evaporation. Fe2Zr was detected in the interfaces of both Zr/Fe and Fe/Zr films after heat treatments above 900°C, while, FeZr3was detected in the Fe/Zr films treated below 900°C. FeZr2was not detected in both films but FeZr2Oxwas observed in Fe/Zr films annealed at 1000°C. The relative amounts of intermetallic phases, which were formed at interfaces, suggest that diffusion of Zr atoms into the Fe substrates mainly occurs in Zr/Fe, whereas diffusion of Fe atoms into Zr substrates is a major process for making intermetallic compounds in Fe/Zr at rather low temperatures.
Annealing of Supersaturated Cobalt in Silicon
Authors: Suwaki Hideo , Hashimoto Kouji , Nakashima Hiroshi , Hashimoto Kimio
Published: November 2005

The annealing of supersaturated cobalt in silicon was investigated by measuring the in-depth profiles of the cobalt concentration as a function of the annealing time at 1100°C. In-depth profiles of the annealing process could be represented by a complementary error function, and the diffusion coefficient is consistent with that of the in-diffusion process.
Oxidation-Enhanced TSC and TSSP of Polyethylene
Authors: Mizutani Teruyoshi , Ikeda Seita , Ieda Masayuki
Published: November 2005

The conduction, TSC and TSSP of both low-density and high-density polyethylene (LDPE and HDPE) were found to be strongly enhanced by oxidation. Oxidized PE showed two TSC peaks, P
1 and P
2. Peak P
1 was caused by the depolarization of C=0 dipoles and peak P
2 originated from injected homo space charge. Thermal pulse experiments revealed the existence of negative and positive homo space charges in oxidized PE polarized at high fields. V
TSSP(T) increased in the temperature regions of peaks P
1 and P
2, and TSSP and TSC were found to be closely related to each other. Peak P
1 and V
TSSP(T) at room temperature were proportional to the concentration of C=0 groups and can be utilized for diagnosing the degradation of PE accompanied by oxidation.
Photoluminescence Study of GaAs-AlGaAs Multiquantum Well Grown by Molecular-Beam Epitaxy
Authors: Ohta Tuneaki , Kobayashi Keisuke L. I. , Nakashima Hisao
Published: November 2005

The spectral and spatial behaviors of the photoluminescence (PL) have been studied in GaAs-AlGaAs multiquantum well (MQW) structures grown by molecular-beam epitaxy at various substrate temperatures. The results indicate that the optimum substrate temperature is in the region of 660-700°C, where the PL intensity is a factor of 100 greater than that at lower temperatures. Interface disorder is observed by PL topography in a sample grown at temperatures higher than 750°C. This disorder is considered to degrade the PL intensities of samples grown above 750°C. The PL topographic observations show that dislocations and oval defects act as nonradiative centers and develop to dark-line defects under high optical excitation in MQW, as in conventional double heterostructures.
Vacuum Ultraviolet Light Source Using Electrodeless Discharge
Authors: Shao Chun-Lin , Jimbo Takashi , Umeno Masayoshi , Hattori Shuzo
Published: November 2005

A new type of vacuum ultraviolet light source employing electrodeless pulse discharge was studied, and the discharge conditions needed to obtain stable VUV radiation were investigated. The argon discharge spectra between 50 nm and 110 nm were studied, and the number of photons detected through a monochromator was estimated to be 2.5×1011 cm-2s-1 at a photon energy of 13.48 eV, a pressure of 5 mTorr of argon, and a flow rate of 12 cm3/min.
Electron Microscope Observation of Au/Si (111) Interface in Atomic Level
Authors: Yokota Yasuhiro , Hashimoto Hatsujiro , Saito Noritsugu , Endoh Hisamitsu
Published: November 2005

Au/Si (111) interfaces were investigated by a high resolution electron microscope in both “cross-sectional” and “flat-on” modes. The epitaxially grown Au (111) films of 10–20 nm thick on Si (111) show a mosaic structure of about 100 nm in diameter making small angle grain boundaries. By the flat-on observation, a fringe contrast of 0.28 nm spacing are observed in the boundary. The cross-sectional observations reveal that the interface is flat and the intermixing layers are formed along the surface in Si side. A long periodicity contrast anomaly was often observed in the intermixing layer images.
Evaluation of the Piezoresistive Properties of Non-Single-Crystal Si Film
Authors: Kanda Yozo
Published: November 2005

An improved means of evaluating piezoresistive properties (PR) of Si thin films is to measure the ratio of the longitudinal effect π
l
, to the transverse effect π
t
, in addition to the gauge factor, temperature coefficient of resistance and temperature coefficient of gauge factor. The PR made by various processes were evaluated. The property of p-type µc-Si:F:H made by d.c. glow discharge with a high power density and at 300–350°C is excellent. This film showed similar symmetry to that of single Si;
π
l
=-2π
t
Pattern Dependence of Color Gamut of Blackness in a Liquid Crystal Display
Authors: Shimomura Teruo
Published: November 2005

A guest-host mode liquid crystal display of a transmission type is investigated. Color gamut of blackness is established from the estimation experiment of color matching and is shown by the CIE 1931 chromaticity diagram and color solid. Blackness of the circle-, square-, triangle-, and H-patterns as influenced by their shape and magnitude is discussed. A Munsell color chip N-1 is used as the matching sample black color and fifty hues of liquid crystal cells are used as test sample colors. Measurement of estimation is done from ascending- and descending-series in the method of adjustment.
Wide Optical-Gap a-Si:O:H Films Prepared from SiH4–CO2 Gas Mixture
Authors: Haga Koichi , Yamamoto Kenji , Kumano Masafumi , Watanabe Hideo
Published: November 2005

Hydrogenated amorphous silicon oxygen alloy films (a-Si:O:H) with wide optical-gap have been prepared by rf glow discharge decomposition of CO2 and SiH4 gas mixture. The optical-gap increases monotonically from 1.76 eV to 2.43 eV with increasing molar fraction of CO2 to SiH4 in the gas phase. A high photoconductivity of 4.1×10-9(Ω·cm)-1 is obtained for the films with the optical-gap of 2.43 eV. Efficient doping is possible in these films and these properties suggest that the films are useful as window materials of photodetectors.
Measurement of Ultrasound Velocity in Gases under High Pressures up to 3.5 GPa
Authors: Kimura Masaki , Hanayama Yoichi , Nishitake Teruo
Published: November 2005

Using the high-pressure apparatus described in a previous paper, the freezing points of nitrogen and krypton at room temperature were determined from the volume and ultrasound velocity changes. The ultrasound velocity of neon was also measured up to 3.5 GPa. Taking account of the results of the ultrasound velocity and the volume measurements, empirical formulae for the pressure dependence of ultrasound velocities of helium, neon, argon, krypton and xenon were proposed. The phase diagram of a krypton and helium gas mixture under high pressures up to 1.6 GPa at room temperature was also obtained from the velocity measurement.
Detection of EL2 in Undoped LEC GaAs by a Novel Variation of Photo-Induced Transient Spectroscopy
Authors: Blight S. R. , Page A. D. , Ladbrooke P. H. , Thomas H.
Published: November 2005

A variation of Photo-Induced Transient Spectroscopy (PITS) is described. By elimination of charge exchange with the surface of semi-insulating GaAs, negative peaks in PITS spectra are suppressed. This allows the transient response of bulk EL2 centres to be detected by PITS in undoped LEC GaAs for the first time.
Ensemble Monte Carlo Simulation of a Velocity-Modulation Field Effect Transistor (VMT)
Authors: Kizilyalli I. C. , Hess K.
Published: November 2005

We present numerical simulations of velocity modulated field effect transistors as proposed by Sakaki. Using self-consistent particle-field Monte Carlo analysis, we assess possible advantages of these novel device structures with respect to switching speed and show the qualitative correctness of Sakaki's ideas. Quantitatively, delays are introduced by the redistribution of electrons in the separated channels.
Plasma CVD of Amorphous AlN from Metalorganic Al Source and Properties of the Deposited Films
Authors: Hasegawa Fumio , Takahashi Tsuyoshi , Kubo Kiyokazu , Nannichi Yasuo
Published: November 2005

AlN films have been successfully deposited by plasma CVD for the first time. Al was supplied by trimethyl Al (TMA) with H2 or N2 carrier gas, and N was supplied as NH3 through separate gas lines. The deposition rate depends upon the TMA supply, and is essentially independent of the NH3 flow rate. The composition of the deposited films was almost AlN, although a small amount of oxygen was always detected. A better film was obtained for the H2 carrier gas than for N2 carrier gas. X-ray diffraction profiles of the deposited films exhibited no crystalline AlN diffracting peaks, suggesting that the films are not crystallized, but the infrared and ultraviolet absorption spectra exhibited the presence of the Al–N bond (650/cm) and an optical band gap of 5.55 eV. The refractive index was about 1.9. These results suggest that the plasma-deposited films possess dominant AlN properties even though they are not crystalline.
Analytical Separation of 2-Soliton Signal in Volterra-Type Ladder Circuit
Authors: Narita Kazuaki
Published: November 2005

We have analytically separated the already-known 2-soliton signal in the Volterra-type ladder circuit into a superposition of two single soliton signals running through their mates during interaction. This separation is physically a natural one, because in the long-wavelength limit the propagation speeds of two single soliton signals originated from a nonlinear effect can be shown, like the total signal, to be independently proportional to the total normalized current or voltage through or across the element. The actual separation is carried out by superposing a 2-soliton solution for the difference-differential equation presented by Quispel et al. (Physica 125A (1984) 344) on the already-known 2-soliton solution for the Volterra-type ladder circuit equation.
The Effect of Thermal Oxidation of Silicon on Boron Diffusion in Extrinsic Conditions
Authors: Ishikawa Yutaka , Nakamichi Ichiro , Matsumoto Satoru , Niimi Tatsuya
Published: November 2005

Boron diffusion during extrinsic conditions in silicon has been investigated under both oxidizing and inert atmospheres for different temperatures (950–1100°C) and times. Oxidation-enhanced diffusion (OED) was found. This result is opposite to the oxidation-retarded diffusion of arsenic case.
Frequency-Dependent Photovoltage-Generating Areas in a Strongly-Inverted Oxidized p-Type Silicon Wafer
Authors: Munakata Chusuke , Honma Noriaki
Published: November 2005

Surface photovoltages (SPVs) excited with a chopped 632.8 nm-wavelength photon beam (PB) were measured with a transparent electrode that covered half of a sample wafer 76 mm in diameter. The PB diameter was kept at 120 µm and the PB power at 1 µW. Since the wafer resistivity was 0.29 Ωm, the wafer surface was considered to be strongly inverted after forming a dry oxide layer 280 nm thick. SPVs were observed by changing the PB-irradiating positions so that the beam both did and did not pass through the transparent electrode. When the PB-chopping frequency was as low as 2 Hz, the SPV appeared across the entire wafer surface. However, the SPV-generating area decreased around the PB-irradiated point as the frequency became high. This can be explained by a distributed resistance and capacitance network model, previously reported by others.
Transient Thermoelectric Effects in GaAs Crystals
Authors: Sasaki Minoru , Horisaka Shuu , Inoue Masasi
Published: November 2005

Dynamic measurements of thermal diffusion processes of conduction carriers and phonons in GaAs crystals have been made in the temperature range 80–300 K using a pulsed laser-induced “transient thermoelectric (TTE)” effect. The initial stage of the decay curves of TTE voltages gives the carrier recombination times τr, from which capture cross sections for electrons and holes are evaluated. During the second stage, three relaxation processes with relaxation times τf, τm, and τs were observed in both n- and p-GaAs; the fast, intermediate, and slow components are associated with electrons at the Γ, X, and L point conduction bands for n-GaAs, and the light, split-off band, and heavy holes for p-GaAs, respectively. The final stage yields the thermal diffusion coefficient D
T and the thermal conductivity κ for phonons in these crystals.
ESR Study of X-Irradiated KNO3
Authors: Tagaya Kimihito
Published: November 2005

Single crystals of KNO3 were irradiated with X-rays at room temperature, and ESR measurements were performed over the temperature range from 85 K to 400 K. The g and hyperfine tensors of some paramagnetic centers were determined, and it was concluded that F, O2
-, O3
- and NO2 centers were produced. The sites and orientations of O2
-, O3
- and NO2 molecules in a KNO3 crystal were also determined. The superhyperfine interactions of F and O2
- centers with adjacent 14N and 39K nuclei were investigated, and the superhyperfine components were determined. Further, isothermal annealing measurements were performed for the F and O3
- centers.
Switching Phenomena in Vinylidene Fluoride / Trifluoroethylene Copolymers near the Curie Point
Authors: Tajitsu Yoshiro , Masuda Toshiya , Furukawa Takeo
Published: November 2005

Ferroelectric switching and dielectric relaxation processes were simultaneously observed by a time-domain measurement of charge responses induced by a step voltage for a 65/35 mol% copolymer of vinylidene fluoride and trifluoroethylene. These processes were separated on the basis of the different field dependences of their characteristic time constants and resulting polarization changes. As the temperature approaches the Curie Point (T
c∼68°C), both the activation field and the amount of reversed polarization associated with the switching process fall to zero. It is found that the switching times under various fields converge to the relaxation time at T
c. This result implies that the switching process is affected by dipole fluctuations, probably at an early stage when the nuclei of reversed domains are created.
Production of Pulse Intense Ion Beam of the Current Density over a Hundred Times Larger than the Child-Langmuir Limit by Magnetieally-Insulated Ion Diode
Authors: Nakagawa Yoshiro , Ariyoshi Takeshi
Published: November 2005

An intense high-density pulsed proton beam (∼200 A/cm2 at the anode surface, an energy of ∼80 keV, and a diode voltage pulse length of 500 ns) was produced by a cylindrical magnetically-insulated ion diode operated in the long-pulse mode. The ion current density was over 80-to 160-times larger than the Child-Langmuir limit on the anode flashboard. A measurement of the high-energy electrons leaked along the insulation magnetic field indicated that the actual diode gap was \lesssim2 mm while the gap length in a vacuum was 7.5 mm. The microwave emission (∼2.45 and ∼50 GHz) wascoincident with ion beam production. These observations suggest that the anode plasma expansion to the cathode during a long pulse and a virtual cathode movement towards the anode due to field fluctuations in the gap were responsible for a strongly enhanced ion beam generation.
Repetitive Liquid Fuse Opening Switch
Authors: Ikuta Kazunari
Published: November 2005

This paper describes a physical consideration of a non-destructive, liquid fuse opening switch for repetitive operation. An analytical form of the opening time of the switch is given, which is checked by numerical computations. The condition for regular operation of an repetitive liquid-fuse opening switch is demonstrated for a case involving the use of a closed channel flow of liquid metal through a liquid dielectric.
Characterization of Co–O Thin Films by X-Ray Fluorescence Using Chemical Shifts of Absorption Edges
Authors: Sakurai Kenji , Iida Atsuo , Gohshi Yohichi
Published: November 2005

The chemical shift of K absorption edges of cobalt oxides were measured by synchrotron radiation excited X-ray fluorescence technique using an energy dispersive detection system. A thin film of less than 100 angstroms can be easily characterized because of the significantly high sensitivity of the present method. The oxidation process of magnetic thin films of Co–O is quantitatively analyzed.
Electrical Properties of Interface-Traps in Selectively Doped AlGaAs/GaAs Heterostructures
Authors: Takikawa Masahiko
Published: November 2005

A hole-trap-like peak appears in the drain current DLTS spectra recorded from a high-electron-mobility transistor fabricated with a selectively doped AlGaAs/GaAs heterostructure grown by molecular-beam epitaxy. The peak is caused by traps which strongly affect the mobility. The emission and the capture activation energy of the traps increases as the gate bias increases. This shows that the traps which remain ata fixed energy level relative to the GaAs conduction band edge exchange electrons with the sub-bands in the accumulation layer. Based on the above characteristics, an analysis of the spectra indicates that interface-traps with a density of 3.8×1010 cm-2 are located at 0.01 eV above the conduction band edge of GaAs, in the potential well of the accumulation layer.
Magnetic Anisotropy of a Cobalt Thin Film Prepared by Oblique Incidence
Authors: Tasaki Akira , Tagawa Kimiteru , Kita Eiji
Published: November 2005

The effect of oblique incidence on the magnetic anisotropy of a Co thin film was studied for films prepared at incidence angles of up to 70 degrees. It was found that the saturation magnetization per unit volume decreased with an increase of the incidence angle (about 60% of that of the bulk when the incidence angle was 65 degrees).
From magnetic torque measurements, it was found that not only the shape anisotropy due to the columnar structure of the film, but also the crystalline anisotropy of the Co metal played an important role in the magnetic characteristics of the film.
Rayleigh Step Bearing with Second-Order Fluid
Authors: Bujurke N. M. , Jagadeeswar M. , Mulimani B. G.
Published: November 2005

An infinite Rayleigh step bearing with a second-order fluid as lubricant was studied and the lubrication qualities were examined. Compact expressions for the pressure distribution, load capacity, and frictional coefficient were obtained. Calculations of the dimensionless load capacity, frictional force and frictional coefficients are presented for specific values of the material parameters. A second-order fluid was found to yield an increase in the load capacity and to decrease the coefficient of friction compared to that of the Newtonian case. The maximum dimensionless load capacity was found to occur at a slightly smaller step ratio, as compared to the Newtonian case. Further, it was found that the frictional coefficient decreases with an increase in the bearing velocity, as expected for an ideal lubricant.
PIG-Type Compact Microwave Metal Ion Source
Authors: Yoshida Yoshikazu , Suzuki Naoki , Onishi Teruhito , Hirofuji Yuichi
Published: November 2005

A compact microwave metal ion source using PIG (Penning lonization Gauge) geometry has been newly developed. This modified PIG ion source introduces a microwave discharge and can generate stable and high density plasma. The size of the source is 60 mm in diameter and 80 mm long. The microwave discharge power is 20∼60 W at a frequency of 2.45 GHz. A tantulum ion beam current of 3.2 µA has been measured with the extraction aperture (2 mm diameter) at an extraction voltage of 13 kV.
Effect of Ambient Gases on Emission Properties of Pd-Ni-Si-Be-B LM Ion Source
Authors: Arimoto Hiroshi , Miyauchi Eizo , Hashimoto Hisao
Published: November 2005

The effects of ambient gases on emission properties of a Pd-Ni-Si-Be-B LM (liquid metal) ion source have been studied. Oxygen and water vapor had a significant effect on the ion emission stability. A decrease in B ion flux was also observed as the operating period continued. This decrease is explained by the selective evaporation of B oxide in the alloy formed by a reaction between boron and water vapor. Very stable and reliable ion emission with a long lifetime (exceeding 100 hours) was obtained by operating the source in a 8×10-9 Torr UHV.
Direct Observation of Atomic Arrangement of High-Tc Superconductor YBa2Cu3O6.74 by High-Resolution Electron Microscopy
Authors: Hiraga Kenji , Shindo Daisuke , Hirabayashi Makoto , Kikuchi Masae , Oh-ishi Katsuyoshi , Syono Yasuhiko
Published: November 2005

The crystal structure of YBa2Cu3O6.74 superconducting oxide with a transition temperature higher than liquid nitrogen temperature has been studied by high-resolution electron microscopy. The observed high-resolution micrograph is consistent with the oxygen-deficient perovskite structure model proposed in previous work with neutron and X-ray diffraction. In the image, Y, Ba and Cu atoms are represented as dark spots with different contrast depending on their atomic numbers. Unoccupied oxygen atom positions are distinguished from occupied oxygen atom positions as brighter regions.
AlGaAs/GaAs Lateral Current Injection (LCI)-MQW Laser Using Impurity-Induced Disordering
Authors: Furuya Akira , Makiuchi Masao , Wada Osamu , Fujii Toshio , Nobuhara Hiroyuki
Published: November 2005

A lateral current injection (LCI) multi-quantum well (MQW) laser, which is a new planar BH laser, has been developed using impurity-induced disordering in a AlGaAs/GaAs MQW structure. It has been demonstrated that the LCI laser exhibits not only a fundamental transversal mode oscillation with a threshold current of 27 mA (pulse) but also an extremely low capacitance of 0.6pF at zero bias voltage, both at room temperature.
O2 Plasma Etch Rate Reduction on Synchrotron Radiation Exposed PMMA Film
Authors: Saito Kunio , Yoshikawa Akira
Published: November 2005

The etch rate of PMMA film in O2 plasma is found to be reduced by synchrotron radiation (SR) exposure. This phenomenon is accompanied by a reduction in film thickness. IR and XPS analyses reveal that this thickness reduction is caused by scission and removal of the ester side chain. Etch rate of the SR-exposed film decreases to about 1/3 of the unexposed film. This characteristic makes dry-development possible.
Spatial Filtering Velocimetry by Dynamic Image Processing
Authors: Miike Hidetoshi , Koga Kazutoshi , Momota Masahiro , Hashimoto Hajime
Published: November 2005

A flexible velocimetry based on dynamic image processing is proposed. Through an analogy of spatial filter technique and laser Doppler velocimetry, a raw dynamic scene is transformed to a scene superposed with a sinusoidal spatial pattern of gray-levels. Using temporal change of accumulated gray value of each frame, we can evaluate velocity information of moving particles by spectral analysis. The validity and usefulness of the velocimetry are confirmed using artificial images created by computer simulation. The effectiveness of the maximum entropy method in the spectral analysis is also emphasized.
Function of Substrate Bias Potential for Formation of Cubic Boron Nitride Films in Plasma CVD Technique
Authors: Chayahara Akiyoshi , Yokoyama Haruki , Imura Takeshi , Osaka Yukio
Published: November 2005

Cubic BN thin films are formed in RF discharge in B2H6 and N2 at low pressures under a magnetic field to confine the plasma, for negatively self-biased substrate electrodes. Ion bombardment on the growing surface is suggested to play an important role in the formation of cubic BN. The deposited films are characterized by infrared absorption spectroscopy and transmission electron microscopy which show that they are composed of microcrystals of cubic BN with 100-200 Å grain size.
Epitaxial Growth of CdTe on InSb(100) by RF Sputtering
Authors: Nishibayashi Yoshiki , Imura Takeshi , Osaka Yukio
Published: November 2005

Cadmium telluride is deposited epitaxially by rf sputtering on the clean surface of InSb(100) substrate from which the surface native oxide has been etched off in advance by H2 plasma treatment. The crystalline quality of CdTe films which depends on the substrate temperature is evaluated by means of the optical reflectance, Raman scattering and RHEED pattern measurements. CdTe films prepared at temperatures of 250-300°C are deposited epitaxially, but those at 100°C are not.
Transition of Ionic Clusters in Ionomers
Authors: Tadano Kenji , Hirasawa Eisaku , Yamamoto Yasufumi , Yamamoto Hitoshi , Yano Shinichi
Published: November 2005

Differential scanning calorimetric and thermal expansion measurements were made for the complex Zn(II) salts of ethylene-methacrylic acid copolymer with 1, 3-bis-aminomethylcyclohexane. One transition of the ionic clusters in the polymer matrix was found near 325 K as a peak on the DSC and thermal expansion curves. The transition exhibited a thermal hysteresis which was explained by the relaxational destruction/reformation of a structure in the inside of ionic clusters.
Increase in Nonradiative Recombination Lifetimes in Semi-Insulating GaAs Observed by a Photoacoustic Technique
Authors: Suemune Ikuo , Uesugi Norio , Kan Yasu , Yamanishi Masamichi
Published: November 2005

Large increases in nonradiative recombination lifetimes were observed for the first time in a In-doped semi-insulating GaAs. The variation ratio of the lifetime increase is over 180 for the incident optical power of 8 mW/cm2. The increase in the diffusion length associated with the lifetime increase in the bulk is also indicated.
Microstructure of a Superconducting Compound La-Sr-Cu-O at Liquid Helium Temperature
Authors: Sugiyama Masaaki , Suyama Ryuji , Kubo Hiroshi
Published: November 2005

Structural change in a compound La-Sr-Cu-O with the K2NiF4 type of structure (tetragonal) has been studied at liquid helium temperature using a cyrogenic transmission electron microscope. The tetragonal phase is transformed into an orthorhombic phase accompanied by internal twinning on cooling, and the trace of an interface of the plate is parallel to that of the (113) plane in the orthorhombic unit cell. Extra reflections with indices 1 0 0, corresponding to a 1/2 1/2 0 reflection in the tetragonal phase, are observed at 4.2 K, and then disappear reversibly by heating to room temperature. The microstructure is also examined by high-resolution electron microscopy at 4.2 K.
Distance Measurement Using a Pulse Train Emitted from a Laser Diode
Authors: Seta Katuo , Oh'ishi Tadanao
Published: November 2005

A distance meter has been developed using a pulse train emitted from a laser diode. The frequency spectrum of the pulse train consists of the fundamental frequency and its harmonics of the modulation current supplied to the laser diode. The interference effect between the detected signal and the field leakage, induced by the modulation current, was removed through the heterodyne detection of the second harmonic, and the systematic error caused from this interference effect was decreased in phase measurements. The precision of the distance measurement was improved, especially when the detected light signal was very weak.
Superconductivity and Crystal Structure of LaBa2Cu3-xOy Compounds
Authors: Yoshizaki Ryozo , Sawada Hideaki , Iwazumi Toshiaki , Saito Yosuke , Abe Yoshihito , Ikeda Hiroshi , Imai Katsuhiro , Nakai Izumi
Published: November 2005

The crystal structure of a sample which shows a superconducting transition onset temperature of 89 K and a transition width of 9 K is determined to be orthorhombic with oxygen-deficient triperovskite structure from Rietveld refinement of X-ray powder diffraction patterns. The crystal data are as follows: LaBa2Cu2.94O7, orthorhombic, space group Pmmm, a = 3.8829(1), b = 3.9342(4), and c = 11.810(1) Å. It is proposed that an orthorhombic structure is essential to the 90 K superconductivity of oxygen-deficient triperovskites and the T
c of their tetragonal forms is around 60 K.
Anomalous Hydrodynamic Behavior of Smectic Liquid Crystals at Low Frequencies
Authors: Yamamoto Jun , Fujita Ken , Inoue Nobuhiko , Nakamura Haruki , Okano Koji
Published: November 2005

We have measured the layer compression modulus and the longitudinal viscosity of smectic-A phase of 8CB, and smectic-A and smectic-C phases of 4O.7 in the frequency range from 50Hz to 1kHz. We found that in this low-frequency regime, the viscosity shows the anomalous frequency dependence of the type \tildeκ/ω predicted theoretically by Mazenko, Ramaswamy and Toner(MRT). The measured \tildeκ has close correlation with the layer compression modulus consistent with the theory, but the observed \tildeκ is one order of magnitude larger than the value estimated from the lowest-order perturbation calculation by MRT.
Formation of Y-Ba-Cu-O Superconducting Film by a Spray Pyrolysis Method
Authors: Kawai Maki , Kawai Tomoji , Masuhira Hiromi , Takahasi Makoto
Published: November 2005

Thin film of YBa2Cu3O7-x
superconductor was formed by a spray pyrolysis method. The temperature dependence of resistance showed the T
c-onset at 95 K and T
c-zero at 83 K with the film on a cubic zirconia single-crystal surface. The X-ray diffraction pattern showed that the structure of the film was pure orthorhombic phase. It was also shown that the oriented film with its c axis perpendicular to the surface was formed with this conventional spray method by controlling the heat-treatment conditions.
Application of Retardation Compensation; A New Highly Multiplexable Black-White Liquid Crystal Display with Two Supertwisted Nematic Layers
Authors: Katoh Kazunori , Endo Yukio , Akatsuka Minoru , Ohgawara Masao , Sawada Kazutoshi
Published: November 2005

Compensation of birefringent retardation is applied to a supertwisted nematic liquid crystal layer. The birefringent effect of the layer is totally canceled by another supertwisted nematic layer of opposite helical sense. Numerical computation confirmed complete extinction of light between crossed polarizers. A highly multiplexable black-white liquid crystal display is obtained with the technique.