bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Reliability of Radiographic Systems by Transmitted Information
Authors: Kanamori Hitoshi , Nakamori Nobuyuki
Published: November 2005

In the evaluation of the reliability of radiographic systems in terms of entropies, continuous variables are sampled or quantized for obtaining their probabilities. In this paper, it is explained that, with the decrease of sampled and quantized intervals, the input-, output- and joint-entropies, H(x), H(y) and H(x, y), diverge positively, whereas the transmitted information T(x; y) converges to a positive finite value. In referring to the conventional formulae for the entropies of continuous variables, T(x; y) is effective. The availability of T(x; y) for the evaluation of the reliability of systems is illustrated. An extrapolation method to determine the value of T(x; y) is given. The present relations are extended to multivariable cases.
Smectic Liquid Crystal Imaging Devices Based on a Photochemical Reaction
Authors: Ogura Katsuyuki , Hirabayashi Hiromitsu , Uejima Atsushi , Nakamura Kenichi
Published: November 2005

Irradiation by ultraviolet or visible light is found to induce a reversible change in the phase transition temperatures of smectic liquid crystals doped with an isomeric compound such as azobenzene. Such irradiation is also found to bring about a reversible change in the threshold voltage for electrohydrodynamic instability and in the electro-optical and thermo-optical characteristics by a photochemical trans (cis)-cis(trans) isomerization. Some experimental results are described for two types of cell; one includes a small amount of electrolyte and the other includes a cholesteric liquid crystal, in addition to the isomeric compound. Some novel imaging devices based on the effects are also proposed, in which an ultraviolet image is converted to a visual image with high contrast and a long-term memory.
Interference Function of Crystalline Embryo Model of Amorphous Metals. I
Authors: Hamada Tadashi , Fujita Francisco Eiichi
Published: November 2005

A simple and possible structural model of amorphous metals based on the concept of crystalline embryos is proposed. The quasi-crystalline clusters are supposed to exist in the liquid state, be enhanced during supercooling, and be frozen as the crystalline embryos in the amorphous state by rapid quenching. A model assembly of atoms containing the crystalline embryos and the boundary regions is constructed, and the pair correlation function and the interference function are calculated. The interference function of the b.c.c. embryo model is in good agreement with experimental ones. It is concluded that the structure of the boundary connecting the embryos plays an essential role as well as the ordered part in the embryos in the diffraction phenomena of the amorphous structures. The importance of chemical clusters and metalloid atoms is also suggested and discussed.
Properties of Congruently-Melting LiNbO3–Fe2O3 Solid-Solution Single Crystals
Authors: Takei Humihiko , Katsumata Tōru
Published: November 2005

The phase transition in single crystals of a congruently-melting LiNbO3–Fe2O3 solid-solution, grown by the Czochralski pulling method, has been investigated using dilatometry. It was found that the Curie point, which corresponded to the phase transition temperature, was greatly lowered by the addition of 0.1 mol% Fe2O3. This effect is tentatively explained as a decrease in covalency in the metal-oxygen octahedra.
Influence of Bombardment by Energetic Atoms on c-Axis Orientation of ZnO Films
Authors: Tominaga Kikuo , Iwamura Satoshi , Fujita Iwao , Shintani Yoshihiro , Tada Osamu
Published: November 2005

The influence of bombardment by high-energy particles on the c-axis orientation of ZnO films was investigated for DC diode sputtering with a hemispherical electrode system and for an RF cylindrical magnetron sputtering system. It was found that one of the criterions for preparing highly [00·2] oriented films is to decrease the flux and energy of high-energy particles bombarding the ZnO film without decreasing the deposition rate of the film. This criterion presents a guide to improving the degree of c-axis orientation in ZnO film in the fabrication of oriented film.
An Ellipsometric Study of Oxide Growth on Nb, Al and Nb3Al Films by rf Plasma
Authors: Katoh Yujiro , Tanabe Keiichi , Michikami Osamu
Published: November 2005

The rf-oxidation process on Nb, Al and Nb3Al films has been investigated by in-situ ellipsometry. The Nb3Al cleaned surface has a refractive index of n=2.98–i3.50 which is close to the Nb-index of n=2.98–i3.41. The Nb, Al and Nb3Al oxide-layers have refractive indices of n≃2.5, n≃1.7 and n≃2.3, respectively. The oxide growth on Nb3Al films obeyed the logarithmic law, the same as with Nb, and was gaverned by the Nb-behavior in the rf discharge rather than by the Al-behavior. The oxygen partial pressure, rather than the rf voltage, was an effective parameter with which to control the thin oxide-layer thicknesses.
V3Si Thin-Film Synthesis by Magnetron Sputtering
Authors: Michikami Osamu , Takenaka Hisataka
Published: November 2005

V3Si thin-films have been produced on a thermally-oxidized Si wafer by magnetron sputtering from an arc-melted target. The phases, lattice constants and superconducting T
c were determined as functions of the substrate temperature and film thickness. The growth orientation of the films was found to change markedly with change in the substrate temperature. V3Si films with T
c higher than 15 K have been obtained at a low substrate temperature of about 600°C. This suggests that thermalization, low substrate bombardment and high sputtering rate play an important role in obtaining high-quality V3Si thin-films.
Blink Furnace Annealing of Ion-Implanted Silicon
Authors: Kugimiya Koichi , Fuse Genshu
Published: November 2005

A very short annealing of a few seconds duration was carried out by irradiating ion-implanted Si wafers with infra-red radiation emitted from hot Si walls. At low temperatures, the activation of impurities was mostly due to the recrystallization of the amorphous layers and to the annihilation of ion-implanted damage; and at high temperatures to thermal agitation. Full activation was generally realized by blink annealing of 10 s at 1000°C and 1 s at 1100°C without noticeable impurity diffusion. Supersaturation of As was electrically observed.
InGaAsP/InP Dual-Wavelength BH Laser
Authors: Nagai Haruo , Noguchi Yoshio , Suzuki Yoshio , Takahei Ken-ichiro
Published: November 2005

A new dual-wavelength BH laser emitting at 1.26 and 1.55 µm has been fabricated. The separation between the two active layers is only 2-3 µm, and independent current injection to each active layer is possible. Simultaneous pulsed operation of the two lasers at room temperature and CW operation at -20°C have been achieved.
Cross-Field Propagation of Intense Neutralized Proton Beam near a Metal Plate
Authors: Ikehata Takashi , Kamada Keiichi , Ishizuka Hiroshi , Kawabe Takaya , Miyoshi Syoichi
Published: November 2005

An intense neutralized proton beam (70 keV, 18 A/cm2, 200–300 ns) is injected into a magnetic field of 2 kG across the magnetic lines of force where a thin metal plate is placed with its surface parallel to the beam axis and perpendicular to the magnetic lines of force. It is found that the polarization electric field in the beam is shorted out by the plate only when the beam is in contact with the plate, and then the beam is deflected according to gyro-motions of the beam protons; otherwise, the polarization electric field is retained and the beam penetrates into the magnetic field without deflection by polarization drift.
LPE Growth of ZnSnAs2 on a ZnSe Substrate from a Sn Solution
Authors: Takenoshita Hiroshi , Nakau Tanehiro
Published: November 2005

The heteroepitaxy of ZnSnAs2 on a ZnSe substrate from a Sn solution has been studied by the LPE method. The lattice mismatch of this combination is 3.26%. The optimum growth conditions were a maximum temperature T
m of 600°C and a cooling rate C
R of 0.5°C/min. The epitaxial growth was confirmed by electron diffraction. From EPMA, the (ZnSnAs2)1-x
–(2ZnSe)
x
alloys were found to form a solid solution. The thickness of the mixed crystal layer was 0.74 µm. The electrical properties of the over-growth layer showed σ=11.9 \varOmega-1-cm-1, µH=78.4 cm2/Vs and N
A=1.30×1018 cm-3 at 300 K.
Self-Modulated Light Outputs from Pulsed Injection Lasers with Optical Feedback
Authors: Ogasawara Nagaatsu , Ito Ryoichi , Sasaki Toru , Osada Toshihito , Suyama Masuo
Published: November 2005

A novel optical feedback effect on pulsed injection lasers, self-modulation of light outputs, has been observed. The results are interpreted in terms of the temporal Q-factor modulation of compound cavity lasers. The transient thermal response of injection lasers has been measured utilizing the newly-discovered phenomena.
Magneto-Optic Kerr Effect in RF Sputtered Co–Cr Film with Perpendicular Anisotropy
Authors: Abe Masanori , Shono Keiji , Kobayashi Kazuo , Gomi Manabu , Nomura Shoichiro
Published: November 2005

The polar Kerr rotation and ellipticity, together with the reflectivity, have been measured at λ≃0.4–0.8 µm, for a Co–Cr film (Cr≃21.5 atomic %) with perpendicular magnetic anisotropy. The film was RF sputter-deposited on an anodized aluminum substrate of a rigid disc. The values of the Kerr double rotation at saturation and remnant magnetization fall in the ranges of 7–9 minutes and 1.2–1.5 minutes, respectively, and that of the double ellipticity at saturation in 1.0–5.5 minutes. The reflectivity is 50–70%. The external-field dependence of the Kerr rotation exhibited a hysteresis with a small coercive force and remanence, in comparison with those obtained by magnetic measurement, indicating that the coercivity near the film surface is weaker than that inside.
Very Thin Oxide Layer on Fe Surface by Mössbauer Spectroscopy
Authors: Shinjo Teruya , Shigematsu Toshihiko , Hosoito Nobuyoshi , Iwasaki Takashi , Takada Toshio
Published: November 2005

A thin 57Fe layer (20Å) was formed by UHV deposition on the surface of 56Fe film (210Å). After exposure to air, Mössbauer and ESCA measurements were carried out. The results show that the oxide layer is fairly uniform with a thickness corresponding to about 12Å of Fe, and that the structure is close to γ–Fe2O3. The recoilless fraction of the thin oxide layer does not greatly deviate from the bulk value.
Direct LPE Growth of InP on (111)A Oriented In0.53Ga0.47As without Dissolution
Authors: Nakajima Kazuo , Yamazaki Susumu , Akita Kenzo
Published: November 2005

Suitable LPE growth conditions needed to obtain (111)A oriented high-quality InP/In0.53Ga0.47As/InP double heterostructures were determined. These conditions were found by investigating the effects of the cooling rate, the degree of supercooling and the growth temperature on the dissolution of In0.53Ga0.47As in In–P solutions. The surface of InP grown on (111)A In0.53Ga0.47As was found to be smooth enough for use in optical devices.
Hole-Burnings Observed at High Energy Tails in Spontaneous Emission Spectra from 1.3 µm-InGaAsP/InP Lasers
Authors: Yamanishi Masamichi , Suemune Ikuo , Nonomura Kazuhiro , Mikoshiba Nobuo
Published: November 2005

Spontaneous emission from 1.3 µm-InGaAsP/InP buried-hetero structure lasers was observed. Spectral hole-burnings, closely correlated to lasings of the devices, were found for the first time. The results are understood on the basis of population-burning of holes associated with saturation of inter-valence-band absorption. It is pointed out that detailed works on relaxation process of hot carriers may lead to a better understanding of long wavelength quaternary lasers.
Magnetic Signals from Human Skeletal Muscles
Authors: Koga Seiki , Nakamura Akira
Published: November 2005

Magnetic singnals from skeletal muscles are obtained when the muscles are contracted. A SQUID magnetometer with a first derivative gradiometer coil is used in a magnetically shielded room. The signals are pulse shaped and together form what is called a magnetomiogram (MMG). The MMG of a right human leg is studied. The waveform of the MMG pulse signal is observed having a pulse width of 4 ms. The position of the MMG signal source is estimated using the dependence of the signal amplitude on the distance between the skin over the leg and the outer surface of the dewar tail. The estimated position of the MMG source is 1 cm beneath the skin.
Magnetically Induced Anisotropy in Amorphous (Fe1-xCox)90Zr10 Alloys
Authors: Fukunaga Hirotoshi , Narita Kenji
Published: November 2005

The composition dependence of induced anisotropy has been investigated for amorphous (Fe1-x
Co
x
)90Zr10 alloys. It is found that the induced anisotropy constant of the alloys shows a clear peak at X=0.6 and its maximum value (3010 erg/g) is three times as large as that reported previously for metal-metalloid amorphous alloys. The composition dependence of induced anisotropy can be fit to the directional pair order theory proposed by Iwata for clustering type fcc alloys.
Stripe Shaped Crystal Growth and Its Model of Silicon Films on Silicon Nitride Layer by Scanning Electron Beam Annealing
Authors: Shibata Kenji , Inoue Tomoyasu , Takigawa Tadahiro
Published: November 2005

Long stripe shaped large grains 0.1–10 mm in length and up to 10 µm in width are grown in poly-Si films on a SiN layer by scanning electron beam annealing. Twin boundaries exist in the grains along the crystal stretching direction. Preannealing at 1000°C for 1 h in N2 has a good effect on the grain growth feature. A model is proposed for the explanation of the long rectangular crystal growth. Characteristics of n-MOSFET's fabricated in electron beam recrystallized poly-Si film are investigated. Threshold voltage, maximum surface mobility, and leakage current were 2.5 V, 250 cm2/V·sec, and 10-10 A, respectively.
Hydrogen in Iron–Its Enhanced Dissolution under Pressure and Stabilization of the γ Phase
Authors: Fukai Yuh , Fukizawa Akira , Watanabe Kenji , Amano Muneyuki
Published: November 2005

Substantial enhancement of the solubility of hydrogen in iron was observed under a pressure of 3 GPa. The concentration reached H/Fe=0.13, and the dissolved hydrogen was found to act as a strong stabilizer of the γ phase.
Direct Observation of Morphology and Growth Rate of Extended Chain Single Crystals of Polyethylene
Authors: Hikosaka Masamichi , Seto Tsuneo
Published: November 2005

Extended chain single crystals (ECSC) of polyethylene growing from liquid under isobaric and isothermal condition were directly observed by microscope in a high pressure apparatus at 3 kbar. ECSC grew as rhombic plate-like crystal several µm thick. The longer diagonal was parallel to the a-axis of hexagonal lattice, the side surfaces were indexed {110} plane, and it seemed that the ECSC was a nearly “perfect crystal”. The growth rate of its longer diagonal G

l
obeyed an experimental formula, G

l
=A·exp
(-B/Δ
T), where A=3.4×103 nm/sec and B=12.6 K, which confirms that the growth rate determining process is a secondary nucleation process.
Inhomogeneous GaAs FET Threshold Voltages Related to Dislocation Distribution
Authors: Nanishi Yasushi , Ishida Satoru , Honda Takashi , Yamazaki Hajime , Miyazawa Shintaro
Published: November 2005

Clear correlation between dislocation distribution and FET threshold voltage distribution in undoped LEC GaAs was observed directly for the first time by automatic computer-controlled measurement of drain-source current (I
ds) and threshold voltage (V
th). FETs fabricated in the high EPD area, which covers the center and the periphery of (100) wafers, showed high I
ds and low V
th, whereas FETs fabricated in the low EPD area showed low I
ds and high V
th.
A Study of the Diffraction of Thermally Scattered Radiation in a Pyrolytic Graphite Crystal by Means of X-Ray Film and Mössbauer Diffraction
Authors: Kashiwase Yasuji , Kainuma Yoshiro , Minoura Masayuki
Published: November 2005

A defect line in the 002 diffuse spot of MoKα X-rays from a pyrolytic graphite crystal was observed in the diffraction pattern on an X-ray film. On the other hand, a dip in the inelastic intensity profile in the 002 Bragg reflection from the same crystal was observed also by means of Mössbauer γ-ray diffraction using 14.4 keV γ-rays and a position-sensitive detector. The correspondence between the defect line and the dip was ascertained using the two methods mentioned above.
Properties of Amorphous Films Prepared from SiH4–N2–H2 Gas Mixture
Authors: Watanabe Hideo , Katoh Kazuhisa , Yasui Masaru
Published: November 2005

The electrical properties and the IR absorption spectra of amorphous films made by the glow-discharge of a SiH4–N2–H2 gas mixture have been investigated as a function of the nitrogen to silane mole fraction. Efficient doping is possible in these amorphous films. The highest resistivity obtained is 1×1014 Ω·cm, which is sufficient to be used as a photoreceptor of electrophotography.
Ga-Doped ZnSe Grown by Molecular Beam Epitaxy for Blue Light Emitting Diodes
Authors: Niina Tatsuhiko , Minato Tetsuo , Yoneda Kiyoshi
Published: November 2005

The MBE-grown ZnSe layer on GaAs (100) with an optimum doping of Ga is found to exhibit an extremely low resistivity and a strong blue near-band-gap photoluminescence (PL) emission (∼4610 Å) without any deep broad emissions at room temperature. At lower Ga-cell temperatures, the carrier concentration and blue PL emission intensity increases significantly owing to an increase in substitutional Ga atoms acting as donors. At higher Ga-cell temperatures, an excess incorporation of Ga results in a reduction of carrier concentration, a decrease in blue PL emission, and a marked increase in deep broad emission (∼5900 Å).
Pattern Size Dependence of Sensitivity of Inorganic SeGe/Ag Resist
Authors: Funakoshi Nobuhiro , Fujimori Susumu , Zembutsu Sakae , Kasai Toshio
Published: November 2005

The pattern size dependence of the resist sensitivity was measured in inorganic SeGe/Ag resist, which can be predicted by the existence of Ag surface diffusion. From this size depedence, it is concluded that SeGe/Ag resist has a high sensitivity in the finer patterns.
The Ag condensation at the edge parts of patterns was also ascertained by a simple diffusion model.
New Structure on TiN(001) Cleaved Surfaces
Authors: Kakibayashi Hiroshi
Published: November 2005

A new tetragonal structure with a
0=12.72 Å and c
0=3.91 Å with a close relation to the original TiN f.c.c. lattice is found to be formed by annealing TiN(001) cleaved surface at 800°C in vacuum. Various treated surfaces, such as Ti deposition and re-nitrogenation of the surface, are annealed to clarify the formation mechanism of this new structure. The new structure is concluded to be formed only under Ti-rich circumstances though the atomic location of Ti and N atoms is not yet clear.
Penetration of Electrons in Materials
Authors: Fujita Hiroshi , Taguchi Eiji
Published: November 2005

A new method for accurate measurement of penetration depth (R) of electrons with various energies in materials was examined, using an irradiation effect in both aluminum and LiF crystals. The results obtained are summarized as follows: a) The value of R markedly decreases with the increasing energy of electrons used for the measurement. b) When R is assumed to be proportional to the nth power of the accelerating voltage, the measured values of n are smaller than those already reported. The value of n becomes almost unity in the voltage range 1.5–2 MV for 0.15 MeV electrons.
Electron Microscopic Observation of Au–Cu Alloy Particles Produced by Coalescence between Au and Cu Smoke Particles
Authors: Kaito Chihiro , Shiojiri Makoto
Published: November 2005

Particles in a mixture of Au smoke and Cu smoke, which were prepared by the gas evaporation technique, have been investigated by electron microscopy. Au–Cu alloy particles are found in the smoke mixed at a location where no metallic vapor exists. The particles collected from the place at atmospheric temperature of 450°C are disordered Au–Cu alloy with lattice parameters in a range from 0.407 to 0.361 nm. The particles collected from the place at 270°C are ordered AuCu–I and Au3Cu. The formation of these alloy particles provides a corroborative evidence for the coalescence of metallic particles.
An Electron Energy-Loss Spectroscopic Study of CaSO4 Crystals
Authors: Huzimura Ryoitiro , Sumida Chitoshi
Published: November 2005

Energy loss spectra of low energy electrons have been obtained for tiny single crystals of CaSO4 as a function of primary electron energy (15 to 300 eV). An explanation for most loss energies is given in terms of cation intraionization, collective excitations of cation p electrons and the partial valence electrons, interionic transitions and electron-hole pair productions.
Photo-Induced Current Spectroscopy for Normally-Off GaAs MESFETs
Authors: Mizutani Takashi
Published: November 2005

Deep levels in a very thin active layer of less than 0.1 µm, such as used for normally-off GaAs MESFETs, were succesfully detected by monitoring photo-induced drain current variation as a function of light wavelength. Four current peaks were observed at 2330, 1750, 1410 and 910 nm wavelengths. Illumination-induced change in the surface depletion layer width is supposed to play an important role in the current variation.
Anomalous Variations in Conductivity of a-Si: H with Nitrogen Doping
Authors: Noguchi Takashi , Usui Setsuo , Sawada Akashi , Kanoh Yasuo , Kikuchi Makoto
Published: November 2005

Nitrogen was doped into discharge-produced a-Si: H during deposition in a SiH4/N2/Ar or in a SiH4/NH3/Ar mixture. It was found that dark conductivity and photoconductivity first increase as the doping gas ratio increases, then decrease, then increase again, and finally decrease again. This anomalous behavior is distinct from that of phosphorous-doped a-Si: H, in which dark conductivity and photoconductivity increase monotonically as PH3/SiH4 increases. The phenomenon is discussed using a tentative model of the variation in the network structure of a-Si1-x
N
x
: H with nitrogen incorporation.
Calculation of a Shadow Cone Formed by Scattering of an Ion Beam from an Atom
Authors: Komaki Ken-ichiro , Ootuka Akio , Fujimoto Fuminori
Published: November 2005

The shadow cone formed by the scattering of ions from an atom was calculated using Moliere potential. Calculated radii of the shadow cone by replacing the Thomas-Fermi radius, a
TF with 0.85 a
TF show a good agreement with an experiment for 1 keV helium ions on a titanium atom.
DLTS Studies on InSb P-N+ Diodes
Authors: Tsukioka Kunio , Miyazawa Hisao
Published: November 2005

DLTS of Si ion implanted planar and mesa type InSb P-N+ diodes has been studied over a temperature range 50–130 K using a lock-in amplifier. No electron trap was observed regardless of bias pulse conditions. A hole trap at 95 meV above the valence band was discovered. Its concentrations are 2×1013 cm-3 for the planar diode annealed at 200°C and 3×1012 cm-3 for the mesa diode annealed at 300°C. These values are considerably smaller than those of the electron traps at 0.12 eV above the valence band in as grown crystals reported by Laff and Fan and Hollis et al.
Electron Beam Enhanced Surface Photovoltage
Authors: Munakata Chusuke , Okazaki Shinji , Yagi Kunihiro
Published: November 2005

A SiO2-covered p-type Si wafer 76 mm in diameter was irradiated by a focused electron beam of 30 keV. The resistivity of the wafer was 1 mΩm, and the SiO2 layer formed by the wet oxidation process was 360 nm thick. Four electron dosages were used: 2×10-7, 5×10-7, 1×10-6 and 5×10-6 C/cm2. After the electron beam irradiation, the surface photovoltage was found to increase in accordance with the dosage, though a photovoltage increment was hardly observed with a 2×10-7 C/cm2. This phenomenon was caused by the increment of positive surface charges that came about as a result of the interface states formed by the electron beam irradiation.
Scaling Laws of Plasma Ablation by Thermal Radiation
Authors: Nishihara Katsunobu
Published: November 2005

Ablation of a plasma by thermal radiation is investigated within a framework of the diffusion approximation for the radiative transfer. The ablation pressure, mass ablation rate and hydrodynamic efficiency are obtained as functions of radiation intensity. The results show great improvement over laser driven ablation.
Mode Stabilized InGaAsP/InP Terrace-Large Optical Cavity Laser Fabricated on Semi-Insulating InP
Authors: Chen T. R. , Yu K. L. , Koren U. , Margalit S. , Yariv A.
Published: November 2005

Mode stabilized terrace-large optical cavity (TR-LOC) lasers have been fabricated on semi-insulating (SI) InP substrates. The fabrication process involves a single-step liquid phase epitaxial (LPE) growth and a lateral Zn diffusion. The laser operates in a stable single transverse mode and is capable of delivering a power exceeding 300 mW/facet (at pulsed operation) with very smooth far-field pattern.
Axial Ratio Change of the L10-Type CuAu1-yPdy Quasibinary Alloys
Authors: Nakahigashi Kiyotaka , Kogachi Mineo , Katada Kinya
Published: November 2005

The composition dependence of the lattice parameters a and c of CuAu1-y
Pd
y
(0≤y<0.53) with the L10-type structure was investigated by X-ray diffraction method. The axial ratio c/a increases with increasing y from 0.926 of the terminal alloy CuAu at first, takes a maximum value of 0.936 at y=0.08, and then decreases almost linearly to 0.856 at y=0.53.
The internal energy of a quasibinary system derived by using the Morse potential function was applied to explain the change in the axial ratio with the composition of present alloy system.
Photoluminescence of Polyacetylene in Near Infrared
Authors: Yoshino Katsumi , Hayashi Shigenori , Sakai Toshihiko , Inuishi Yoshio , Kato Hiroshi , Watanabe Yasutaka
Published: November 2005

Photoluminescence of cis-(CH)
x
is observed at around 640 nm and 900 nm. But both emissions disappear after the isomerization to trans-(CH)
x
by heat treatment. The excitation spectrum of 900 nm emission has the maximum at around 800 nm, which nearly coincides with the absorption edge of trans-(CH)
x
. Temperature dependences of these emission spectra are also investigated.
Preparation of PbTiO3 Ferroelectric Thin Film by Chemical Vapor Deposition
Authors: Nakagawa Taichi , Yamaguchi Jiro , Okuyama Masanori , Hamakawa Yoshihiro
Published: November 2005

Chemical vapor deposition of PbTiO3 thin film on the substrate of Pt plate has been successfully made. (100)- and (001)-oriented PbTiO3 film has been obtained under a certain deposition condition. Surface of the film is smoother and the deposition rate of 8.3 µm/h is much higher, as compared with those of conventional sputtering method.
A Model of Linear Uranium Accumulation for ESR Age of Heidelberg (Mauer) and Tautavel Bones
Authors: Ikeya Motoji
Published: November 2005

Electron spin resonance (ESR) dating of anthropologically important Heidelberg and Tautavel bones has been made based on a model of uranium-series disequilibrium and a linear accumulation of uranium. Theoretical equation and graphic solution are presented to obtain the age from the total dose of natural radiation (TD) derived from the result of ESR dating. The model shifts the ESR ages considerably to the old side as the accumulation of uranium into an open-system fossil bone was taken into account.
Studies of an Impulse Breakdown Process in an Atmospheric Air Using Ruby-Laser Scattering Diagnostics
Authors: Uchino Kiichiro , Muraoka Tetsuhiro , Muraoka Katsunori , Akazaki Masanori
Published: November 2005

Local measurements of impulse breakdown plasmas in an atmospheric air using ruby-laser scattering revealed that pressure as high as 12 atm (electron density≃1.3×1024m-3 and temperature≃3.4 eV) and an electric field of 2.8×104 V/m were reached in the arc channel just after the beginning of the discharge (t=0.4 µsec), and that they rapidly approached respective values at DC discharge in the air. The pressure in the arc channel was found uniform across the channel radius each time, and the initial pressure in, and the expansion velocity of, the arc channel at t=0.4 µsec, were enough to cause the resulting shock-wave expansion at later times.
Proton-Beam Transport through Wall-Confined Plasma Channel in the Nagaoka ETIGO-I
Authors: Yamada Tetsuo , Masugata Katsumi , Yatsui Kiyoshi , Matsui Masao
Published: November 2005

Transport of an intense pulsed proton beam has been studied experimentally through a wall-confined plasma channel (1-m long) in the Nagaoka ETIGO-I. A proton beam with an energy of 800-keV is injected into the channel. The transport efficiency increases with increasing channel current or decreasing channel pressure, being in good agreement with the existing theories. Changing the timing between channel current and beam injection, we have found that there exists a good timing for the beam injection. In some cases, the beam ceases to be transported probably due to some plasma instabilities.
A Study of Electron Mobility and Electron-Phonon Interaction in Si MOSFETs by Negative Magnetoresistance Experiments
Authors: Kawaguchi Yoichi , Kawaji Shinji
Published: November 2005

Hot-electron effect in Si(001) MOSFET's has been studied at 4.2 K and 1.1 K by use of negative magnetoresistance as a thermometer for electron temperature. Heat transfer from electron system to phonon system is explained by use of deformation potential constants in Si bulk. Possible ultimate electron mobility in Si MOSFET's is discussed.
Solid Phase Epitaxy of Highly-Doped Si: B Films Deposited on Si(100) Substrates
Authors: Caber Jan , Ishiwara Hiroshi , Furukawa Seijiro
Published: November 2005

The solid phase epitaxial growth of amorphous Si: B films formed by vacuum evaporation of Si: B alloys has been investigated. It has been found from Rutherford backscattering spectroscopy and transmission electron microscopy that the crystalline quality of the grown layer is excellent even if the boron concentration exceeds the solid solubility limit in thermal equilibrium. It has also been found from nuclear reaction and electrical measurements that the incorporated boron atoms exhibit 100% electrical activity at least up to 2×1020cm-3 and that the carrier concentration is nearly constant in the layer.
Neutron Yield in a Repetitive Dense Plasma Focus
Authors: Ueno Isao , Ikuta Kazunari , Taguchi Yuichi , Tanimoto Mitsumori , Nakazawa Masaharu , Kido Giyuu
Published: November 2005

A first, preliminary result of the neutron yield from a repetitively produced dense plasma focus is reported, where the repetitive focalization of plasma is performed at the top end of the inner electrode of the plasma focus device. The number of repetitions of plasma was elected to be more than 10 in a single discharge of the capacitor bank. In the case of a small repetition number of plasma production, the scaling law of neutron yield seems to be the standard one for a single focus event in a single discharge of the capacitor bank.
Optical Transmission Loss of As–S Glass Fiber in 1.0–5.5 µm Wavelength Region
Authors: Miyashita Tadashi , Terunuma Yukio
Published: November 2005

The optical transmission loss spectrum of an arsenic sulphide glass fiber was measured in a wavelength region between 1.0 and 5.5 µm. Minimum losses of 92 dB/km at 1.85 µm, 78 dB/km at 2.4 µm and 164 dB/km at 5.3 µm were obtained in the fiber with a small tail on the band edge absorption. The fiber was drawn from a high purity glass rod.
Observations of CmFn Radicals in Reactive Ion Beam Etching
Authors: Hayashi Toshio , Miyamura Masao , Komiya Souji
Published: November 2005

CmFn radicals produced in an electron-cyclotron-resonance ion source for reactive ion beam etching of SiO2 were observed with photoionization mass spectrometry. Pressure dependence of the densities of radicals shows an apparent contribution of the radicals to the etching rate in a pressure region higher than about 2×10-2 Pa.
Anomalous Optical and Structural Properties of B-Doped a-Si:H
Authors: Yamasaki Satoshi , Matsuda Akihisa , Tanaka Kazunobu
Published: November 2005

The optical absorption edge spectra, the bonded H content and H evolution measurements have been carried out on B-doped a-Si:H as functions of the dopant gas ratio of B2H6/SiH4. The number of H atoms bonded to Si network decreases as the doping ratio increases, while non-bonded H's are involved only in the heavily B-doped specimen. It has been demonstrated that the film texture changes drastically in a high doping region, resulting in anomalous change in the optical absorption spectra over a whole photon-energy range.
Thermal Stability of Pure a-Si Films Prepared by rf-Bias Sputtering
Authors: Suzuki Masakuni , Suzuki Makoto , Kanada Matahiko , Kakimoto Yoshio
Published: November 2005

Pure amorphous-silicon (a-Si) films, in which dangling bond terminators such as hydrogen or fluorine are not contained, were prepared using rf-bias sputtering with a magnetron target. The temperature dependence of dark conductivity (σd), photoconductivity (Δσp), ESR spin density (N
s) and their variation with annealing were studied. It was found that σd and Δσp were unchanged even after annealing at 500°C, and that the variation of N
s with annealing was similar to that of purely fluorinated a-Si (a-Si:F), and much smaller than that of hydrogenated a-Si (a-Si:H).
Point Defects in Nb22O54 Oxidized at 200°C
Authors: Horiuchi Shigeo , Kimura Shigeyuki
Published: November 2005

The structural changes in a Nb22O54 crystal heated at 200°C in air were examined using 1 MV high-resolution transmission electron microscopy. At the initial stage of oxidation, NbO6 octahedra are locally shifted by one atomic distance. This movement induces two types of point defect, which array in a string of limited length. Both require additional oxygen atoms at the interstitial sites and, therefore, can act as a possible mechanism for oxidation. At the advanced stage of oxidation, a superstructure is formed.
Residual Gas Adsorption on Electrode Surfaces in Vacuum
Authors: Tsuruta Koichi , Yano Makoto
Published: November 2005

The pre-breakdown currents of a vacuum gap both just after spark conditioning of the electrodes and after exposure to a vacuum were measured in a vacuum of 3×10-5 Pa using a switching impulse voltage. It was found that the exposure reduced the field emission current and that this reduction became greater with the exposure time. The reduction in the field emission current is considered to be the result of an increase in the work function due to adsorption of residual gases on the electrode surfaces. Current pulses were also observed to appear on the pre-breakdown currents measured after exposures of longer than 5 minutes.
Electron Temperature in HF Discharge Plasma Columns
Authors: Cicconi G.
Published: November 2005

Assuming the validity of Schottky's theory for the positive column, the electron temperature of plasma columns in HF stationary discharges is estimated by measuring their length. The discharges are produced in narrow quartz tubes. At particularly low pressure for a quasi capillary column, the estimation is made by a microwave reflectometric diagnostic using various equilibrium models to describe the column.
Electrical Characteristics of an Upper Interface on a Buried SiO2 Layer Formed by Oxygen Implantation
Authors: Nakashima Sadao , Ohwada Kuniki
Published: November 2005

The electrical characteristics of an upper interface on a buried oxide layer formed by oxygen implantation in an Si wafer and subsequent thermal annealing were studied using an MOS diode and capacitance-voltage (C-V) measurements. The measured C-V curves strongly depended on the ion dose. The C-V curve was independent of the gate voltage for a dose of 1.2×1018 cm-2, voltage-dependent for doses above 1.8×1018 cm-2, and similar to those for thermal oxide for a dose of 2.4×1018 cm-2. This strong dependence on the ion dose is considered to result from a change in the interface structure with increase in dose. In this change, the transition layer existing between the buried oxide and the upper Si layer at low doses, which shields the upper Si layer from external electric fields, disappears with increase in dose.
Relation Between Frequency and Intensity Stabilities in AlGaAs Semiconductor Laser
Authors: Tsuchida Hidemi , Tako Toshiharu
Published: November 2005

The frequency and intensity stabilities of an AlGaAs semiconductor laser are measured during free-running, frequency-stabilized and intensity-stabilized operations. Each stabilization mode is achieved by controlling the injection current. The experimental results are discussed and the causes for the frequency and intensity fluctuations considered. The feasibility of simultaneously stabilizing both the frequency and the intensity is also discussed. It is concluded that simultaneous stabilization cannot be achieved by controlling the injection current alone.
Diffusion Coefficient of Electrons in Real Space
Authors: Ikuta Nobuaki , Itoh Hidenori , Toyota Kazushige
Published: November 2005

A Monte-Carlo simulation of electron motion is carried out by a new method to obtain the exact values of swarm parameters. The elastic and total collision cross sections assumed here are proportional to various powers of the electron energy, and the mass ratio of an electron to a gas atom is taken as 10-2. Computation shows that the well-known expression for the diffusion doefficient D
v does not always give the exact values of the lateral diffusion coefficient D
T. The differences between the values of D
v and D
T are significant when the power value of the collision cross-section is large or the mass ratio is large. The disagreement is thought to be caused by the difference in the procedures for obtaining D
v and D
T because of the difference in their definitions.
Excitation of the Electron Plasma Waves in a Magnetized Plasma by a Slow Waveguiding Circuit
Authors: Idehara Toshitaka
Published: November 2005

The excitation of the electron plasma wave in a magnetized plasma (the Trivelpiece-Gould wave) is studied experimentally, using a slow waveguiding circuit surrounding the plasma column. The wave vector of the excited wave can be controlled externally. In the case of weak inhomogeneity, the group velocity v_g of the excited wave makes a right-angle with the phase velocity v_ph. In the lower branch of the wave (ω<ωc), the wave propagates as a forward wave in the axial direction and as a backward wave in the radial direction. In the upper branch (ω>ωc), it propagates as a backward wave in the axial direction and as a forward wave in the radial direction.
Toroidal Plasma Device with a Helical Magnetic Axis: Asperator NP-4
Authors: Funato Yasuyuki , Sakamoto Isao , Watanabe Hiroshige
Published: November 2005

A new magnetic trap with a three-dimensional magnetic axis is designed and constructed and the results together with the properties of the magnetic field configuration of the system are described. The field configuration of the device is characterized by a non-planar axis with a multi-field period ofn=8 around the torus, an extremely high rotational transform angle ofl/2π=5.6 and good helical symmetry. Engineering problems in the fabrication of the vacuum chamber and the magnetic coil system and the overall construction of the device are discussed. The magnetic field configuration measured by the electron beam method and a magnetic probe agrees well with the result of numerical calculation.
Vapor Growth Characteristics of ZnTe in the Horizontal Open-Tube System and Its Thermodynamic Analysis
Authors: Nishio Mitsuhiro , Nakamura Yoshihiro , Ogawa Hiroshi
Published: November 2005

The growth and source-depletion characteristics of ZnTe were investigated by the horizontal open-tube method using H2 carrier gas. The system consists of vapor-etching, supersaturation gas (preferential growth), nucleation and reactor-wall deposition regions from the source-zone downstream. The preferential growth region widens owing to the decrease in the nucleation temperature along with the decrease in the temperature gradient near the source-zone or the flow rate. This region gives smooth, flat epi-layers and can be described by a quasi-equilibrium model. On the other hand, the reactor-wall deposition characteristics can be expressed by a complete equilibrium model if a substrate is set at a position far enough from the critical-nucleation position. Thermodynamic analysis of the laminar and diffusion flows gives good agreement with the experimental results.
Internal Stress in V3Si Thin Films Prepared by Magnetron Sputtering
Authors: Takenaka Hisataka , Michikami Osamu
Published: November 2005

The internal stress in V3Si film prepared by magnetron sputtering on thermally-oxidized Si substrates was measured as a function of the substrate temperature T
s by the optical interference method. The intrinsic stress in the film has a maximum value at the value of T
s at which the crystalline film starts to be deposited. It then decreases with increase in T
s. The thermal stress also changes markedly at almost the same value of T
s, and increases with T
s. The value of the intrinsic stress in a well-ordered film deposited at T
s=570°C is approximately 1×109 dyn/cm2 (tension). The thermal expansion coefficients and Young's moduli for films deposited at various values of T
s have been derived from these data. The effect of stress on the film lattice constants is discussed.
Properties of Passivating Silicon Oxide Films due to HF–NO2 Gas Reaction
Authors: Ito Hideo , Ono Kazumasa
Published: November 2005

A microcrystalline silicon film is formed on monocrystalline silicon by a staining reaction in a gaseous mixture of HF and NO2, and the film is then oxidized at 100°C∼500°C. The oxide thickness depends upon the oxidation temperature, although almost all of the oxidation is completed in the first few minutes. It is also found that the unoxidized thickness left between the oxide and the silicon substrate is important in stabilizing the surface. The most suitable oxidation temperature for the device passivation is 200°C∼250°C. The low-temperature oxidation mechanism and the physical properties of the films are discussed.
Linear Dispersion of Ionization Wave in Small-Bore Discharge Tube
Authors: Amemiya Hiroshi
Published: November 2005

In discharge tubes of small radius such as gas laser tubes, the ratio of the group to phase velocity is larger than unity. The present paper shows that this discrepancy is mainly due to the finite radius effect. First, experimental results are given. Next, Pekarek's theory is modified by including the effect-mentioned above, and the result is then compared with the experiment.
An Analytical Approach to Empirical Law on the Transition Voltage from Polbüschel to Gleitbüschel using a Transmission Line Model
Authors: Kanematsu Atsushi , Sawa Goro , Ieda Masayuki
Published: November 2005

In surface discharge, a transition from Polbüschel to Gleitbüschel takes place as the applied voltage is increased. The transition voltage V
g is empirically proportional to C
0
-1/n
(n=2∼3), C
0 being the specific capacitance. In this paper, the relation between V
g and C
0 is introduced analytically using an equivalent transmission line model for the surface streamer. The assumption is made that the transition occurs when the total amount of energy dissipated in the whole streamer stem reaches a given critical value. The analytical relation obtained agrees comparatively well with the empirical one, if the circuit parameters are chosen appropriately.
Characteristics of a Parallel Plate Avalanche Counter with Thin-Film Electrodes
Authors: Tsumaki Koji
Published: November 2005

A small parallel plate avalanche counter (PPAC) consisting of a 0.2 µm-thick stretched polypropylene film was fabricated. Its characteristics as a time-sensitive detector were examined with α-particles from an 241Am source, and a time resolution of 150 psec was obtained. The pulse height distribution of the avalanche electrons was observed and the cause of the distribution was studied. The distribution could be explained as a result of two kinds of fluctuation resulting from energy loss and electron avalanche multiplication.
Stopping Cross-Sections of Rare Gases in Amorphous Silicon for MeV Energy Helium Ions
Authors: Ootuka Akio , Komaki Ken-ichiro , Fujimoto Fuminori , Kawatsura Kiyoshi , Ozawa Kunio , Shimada Toshikazu , Katayama Yoshifumi
Published: November 2005

Using the Rutherford backscattering method, the stopping cross-sections of amorphous silicon doped with rare gases to a concentration of a few percent were measured for helium ions. The effective stopping cross-sections of the rare gases were deduced by assuming Bragg's rule and by using Ziegler's cross-section values for silicon. The results were systematically about 30 percent lower than Ziegler's values for the gaseous state, in the energy range near 1 MeV. The incident energies were 1.0–2.6 MeV for samples containing 8% argon, and 1.0–1.6 MeV for those containing 7% krypton or 4% xenon.
Degradation of Sodium-Polyacrylate in Dilute Aqueous Solution, II
Authors: Saita Takao , Matumura On
Published: November 2005

It has been found that Na-PAA molecules in dilute aqueous solution are degraded by shearing stress, oxidation and photolysis during usual viscosity measurements with a capillary viscometer. The results of previous viscosity measurements, mainly about the mechanochemical degradation in air and in air-free conditions, showed that the degradation rate increases with increasing shear stress, and with decreasing polymer concentration. In this work, the effects of the molecular weight and temperature on the degradation rate are measured using a capillary viscometer in air, and the photodegradation of Na-PAA and PAA in aqueous solution irradiated with UV light are studied by viscosity measurements in air, and by UV absorption and ESR methods. The results show that the degradation of molecules is enhanced by an increase in the molecular weight and strongly accelerated by a rise in temperature and by UV irradiation, and is accompanied by free-radical chain reactions.
Energy-Dependent Neutron Detection Sensitivity of Cellulose Nitrate Track Detector
Authors: Sawamura Teruko , Narita Masakuni , Fujita Fumiyuki , Kudo Katsuhisa , Michikawa Taich
Published: November 2005

A cellulose nitrate track detector, LR-115 (Type II), was studied experimentally to observe its neutron energy response when a radiator, such as fissionable material, is absent. The detector was exposed to monochromatic neutrons from the D (d, n) He reaction produced by a Van de Graaf accelerator. Through-etched and almost through-etched tracks in the detector were counted by two different methods: 1) optical microscope counting with an automatic image analyzing system and 2) spark counting.
The detection sensitivity was obtained in the neutron energy region lower than 5 MeV and it was found that only α-particles from (n, α) reactions could be detected in both counting methods. We derived the counting probability of α-tracks induced in the detector and the threshold energies for neutron detection.
Effect of Well Size Fluctuation on Photoluminescence Spectrum of AlAs–GaAs Superlattices
Authors: Goldstein Leon , Horikoshi Yoshiji , Tarucha Seigo , Okamoto Hiroshi
Published: November 2005

Photoluminescence spectra for undoped superlattices exhibited smaller half widths compared with those obtained in GaAs bulk crystals. However, both the spectral width and shape were found to be very sensitive to the well size. When the well size is greater than about 80 Å, the spectrum at 77 K showed smaller linewidth, which agrees with theoretical results, whereas when the well size is smaller than this, the spectral width increased with decreasing well size. In some cases, additional emission bands appeared in the lower energy side of the main emission peak. These phenomena were interpreted in terms of well size fluctuations.