bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of Pole Shapes for Quadrupole Magnets Having Circular Pole Tips
Authors: Kobayashi Masaaki
Published: November 2005

Harmonic field contents of quadrupole magnets having circular pole tips of various radii R

p
's and rectangular coil slots at various distances L

c
u
t
's from the centre were numerically calculated by using two dimensional scalar potentials. Optimum radius of circular pole tip varies from 1.0088 to 1.1374 times the gap radius R

g
as L

c
u
t
from 0.8 to 1.4 times R

g
. Designs of optimum pole shapes for drift tube quadrupole magnets are discussed from harmonic field content, available coil space, core saturation and problems in fabrication. Flat poles as a limit of large pole tip radii were also calculated. A few measurements are compared with the calculations.
The Effect of Current Fluctuation on Dendritic Crystal Growth of Silver by Electrolysis
Authors: Horiuchi Toshio , Kammel Roland
Published: November 2005

Dendritic crystal growth of silver by electrodeposition from silver nitrate aq. solution is analyzed as to the relation between crystal forms and current fluctuation. The crystal form is specified by branching of trees and the growth velocity of needle tip, on the other hand the fluctuation of current is characterized by the time derivative of electrolytic current. The peaks in the current signal coincide with the rapid growth of isolated needle and the valley with the formation of branches. Thus the fluctuation of current corresponds to the formation of dendrites. Using the coincidence it may be possible to control the form of electrodeposited crystals, especially of dendrites, in real time by the adjustment of cell voltage according to the current fluctuation signal. The current fluctuation is interpreted as the concurrent formation of active sites and their inhibition.
A Facile Cryostat for Neutron Diffraction Experiments
Authors: Hirakawa Kinshiro , Ikeda Hironobu
Published: November 2005

A facile conduction-type cryostat for neutron diffraction experiments is designed. This portable cryostat is much easier to operate than the conventional type. Liquid helium of about 2 liters can stay for fifty hours or more, and this cryostat is used at any temperature between the room temperature and 4.2 K.
Growth of Gas Bubbles in Deformable Solids with Time-Dependent Heat and Mass Sources
Authors: Yang Wen-Jei
Published: November 2005

The equations governing the growth of a spherical inert-gas bubble in a deformable solid resulting from the generation of gas atoms from time-dependent gas sources in the solid matrix are formulated for the general case which includes the effects of surface tension, heat diffusion and time-varying heat sources in the matrix. The dimensionless parameters controlling bubble dynamics are identified. Asymptotic solutions valid for large times are obtained to predict the radius-time relation, the creep rate, and the rates of heat and gas diffusion. Bubble growth in the absence of temperature gradient is also examined.
Mössbauer Study of Strain Sensitive Properties of KCoF3 and KFeF3
Authors: Morimoto Setsu , Ito Atsuko
Published: November 2005

Strain sensitive properties of KCoF3 and KFeF3 are studied using Mössbauer spectroscopy. The line broadening in a spectrum and the distribution of T

N
were observed for a powder sample prepared by grinding or cleaving single crystals. If a thin slice (150 µm in thickness) of KCoF3 with a {100} plane was made by polishing, an antiferromagnetic domain perpendicular to the crystal surface was exclusively formed with decreasing temperature through T

N
. Internal strains caused by grinding, cleaving and polishing were found to be responsible for the phenomena mentioned above. Annealing at 740°C in argon gas or etching in the 15% solution of hydro-chloric acid was successfully applied to remove the internal strains.
TEM, AES and XPS Studies of Si Layer on Buried SiO2 Layer Formed by High-Dose Oxygen Ion-Implantation
Authors: Hayashi Takayoshi , Maeyama Satoshi , Yoshii Shizuka
Published: November 2005

Depth distributions of crystallographic and chemical properties in oxygen ion-implanted Si layers have been studied by TEM, AES and XPS. Oxygen ions (16O+) were implanted into (100)-Si wafers at 150 keV to a dose of 1.2×1018/cm2. The dose rate was about 15 µA/cm2. The implanted oxygen forms a buried SiO2 layer after annealing. The Si layer on this buried SiO2 layer is not completely amorphized by implantation, and changes after annealing to a single crystal Si layer at the surface region and a deeper polycrystalline Si layer. A twin layer is formed at the interface region between these two layers. The polycrystalline Si layer consists of a mixture of Si and SiO2.
Sumoto Effect under Transient Conditions
Authors: Mirza J. S.
Published: November 2005

Sumoto effect–the rise of a liquid sheath around charged wire–has only been qualitatively explained. The space charge, held responsible for the phenomenon, has not been experimentally studied.
In this paper, for the first time, a study of this phenomenon is made under transient conditions, rather than with conventional steady-state conditions to experimentally study the space charge effect, if any. The apparatus used is described in detail.
The presence and development of space charge can be fairly interpreted from the results, and the transient study can be expected to lead to quantitative explanation. It has been observed that column rise lags behind the onset of step voltage and delay time is commensurate with expected ionic mobility. The magnitude of rise is found to be dependent upon the level of applied voltage and viscosity of liquid. Through these observations the mode of development of space charge and the ionic mobility can be estimated.
Faraday Rotation and Birefringence of Fe3BO6
Authors: Abe Masanori , Gomi Manabu , Nomura Shoichiro
Published: November 2005

The intrinsic Faraday rotation and birefringence of Fe3BO6 are measured in a wavelength range of 0.6∼0.7 µm; along the a axis below and along the c axis above the spin reorientation temperature. The birefringence is about three times as large as that of orthoferrite YFe1-x
Co
x/2Ti
x/2O3. The Faraday rotation along the a axis is found to be 1.4×103 deg/cm, about three times as large as that along the c axis. This value is a little smaller if compared with the Faraday rotation of the orthoferrite along the a axis. The Faraday rotation of Fe3BO6 is anisotropic as in the case of orthoferrites, and is of the same magnitude as that of Y3Fe5O12, though the spontaneous magnetization of Fe3BO6 is two orders of magnitude smaller than that of Y3Fe5O12. This may be ascribed to the anisotropic character of the Fe3+ ions.
The Thermal Neutron Cross-Section of 30Si
Authors: Kaminishi Kunio
Published: November 2005

The cross-section of the 30Si (n, γ) 31Si reaction at the thermal energy is determined using an activation method. A new method of determining the self-scattering and absorption factor is described. The result is σ=0.104±0.009 b. This value agrees well with published data.
Phase Relations in the Cu3Ag1-xAux, Ag3Au1-xCux and Au3Cu1-xAgx Ternary Systems
Authors: Kogachi Mineo , Nakahigashi Kiyotaka
Published: November 2005

The phase relations of Cu3Ag1-x
Au
x
, Ag3Au1-x
Cu
x
and Au3Cu1-x
Ag
x
(0≤x≤1) were studied by X-ray diffractometry and differential thermal analysis. In the Cu3Ag1-x
Au
x
and Ag3Au1-x
Cu
x
systems, an Al-type solid solution phase α, an L12-type ordered phase α' and two kinds of two-phase region, α(Cu)+α(Ag) and α'(Cu)+α(Ag), were observed, and the phase boundaries were determined. α(Cu) means a Cu-rich phase of the Al type. On the other hand, in the Au3Cu1-x
Ag
x
system, only an α-phase was detected over the whole composition range, except for x=0 (Au3Cu). The experimental results were interpreted by a treatment based on the Bragg-Williams approximation.
Photoelectric Emission from KCl in the Photon Energy Region from 1.0 to 6.0 eV
Authors: Kasai Akinari , Ohishi Kazuo
Published: November 2005

Photoemission was observed from shallower levels than the valence band maximum. This supports the model that surface levels exist in the band gap and electrons are emitted from these levels. On the whole, the yield curve of pure KCl is divided into two parts: small yields below 4.0 eV and a structured exponential rise above 4.0 eV. From this, the Fermi level of the surface is estimated to be situated 4.0 eV below the vacuum level. The exponential rise is modified by structures such as shoulder and dip. Compared with the curve of pure KCl, the yield curve of coloured KCl suggests that the photoemission reflects surface rather than bulk properties.
Development and Performance Characteristics of a UV-Preionized, High-Power TEA Pulsed CO2-Laser
Authors: Ohwadano Yoshiro , Sekiguchi Tadashi
Published: November 2005

This paper presents a series of systematic studies on a UV-preionized, high-power TEA pulsed CO2-laser with a total laser output energy exceeding 300 joules, a peak output power of GW level and a duration of the first spike of about 50 ns. The studies include (1) the preionization characteristics under UV-irradiation generated by an intense arc-discharge-gap assembly, (2) the main laser discharge characteristics in combination with the UV-preionizing scheme, (3) the optimum relative concentration of the laser gas mixture for maximum peak value of the small-signal gain, and (4) the laser oscillation characteristics using appropriate optical resonator systems which maximize the laser output energy contained in the first spike.
Temperature Dependence of the Delayed Fluorescence Lifetime in Anthracene Crystals with Triplet Exciton Traps
Authors: Yokoi Kohei , Ohba Yujiro
Published: November 2005

The lifetime of delayed fluorescence of anthracene crystals excited by the chopped-light of a He-Ne laser is investigated as a function of temperature over the range 110∼480 K. As compared with the fluorescence intensity, the lifetime is not influenced much by the temperature dependence of triplet-triplet annihilation rate and singlet-triplet absorption coefficient. Considering a trap saturation effect, an analysis has been made of the temperature dependence of the lifetime. In defect-induced crystals, three kinds of defects are observed by X-ray irradiation. Two are 0.33 and 0.16 eV in triplet trap depth, and the trapped triplet decay rate is ∼5×106 s-1 for both; the other is 0.29 eV and ∼1 s-1. The latter is of a different type from the former, namely, it is almost a pure trapping center which hardly quenches triplet excitons.
Electrical Characteristics of Depletion-Type SOS MOS Devices
Authors: Onga Shinji , Ko Wen H. , Hatanaka Katsunori , Kawaji Shinji
Published: November 2005

(001) Si films on (1̄012) sapphire substrates have preferential dislocation arrays in the <110> Si direction. In more detailed observation, dislocation arrays in the [110] Si direction are preferential to those in the [11̄0] Si direction. A new significant anisotropy in the electron mobility of D-type SOS MOS devices is observed, and it is found to be due to the anisotropic dislocation arrays. Furthermore, the surface state density at the Si-SiO2 interface is measured as 2×1011∼8×1011/cm2·eV. These high densities of states are due to crystalline defects, mostly dislocations. Mobility humps are observed in the curves of µH vs. V
G for D-type SOS MOS devices, which phenomena can be explained by a model based on a change in the quantized subband structure with strain-induced anisotropic valley configuration. The appearance of the mobility humps closely resembles those in E-type SOS MOS devices.
Energy Band Structure and Lattice Constant Chart of III-V Mixed Semiconductors, and AlGaSb/AlGaAsSb Semiconductor Lasers on GaSb Substrates
Authors: Sasaki Akio , Nishiuma Masahiro , Takeda Yoshikazu
Published: November 2005

Variations in energy gap, band structure, and relative dielectric constants were examined in 18 ternary and 15 quaternary III-V mixed semiconductor materials for optical devices. A semiconductor laser constructed with AlGaSb/AlGaAsSb on GaSb emitting a wavelength in the range from 1.3 to 1.7 µm is described. Uniform layers of mixed semiconductors, AlGaSb and AlGaAsSb, were successfully grown on a (111)B-oriented GaSb substrate. Lasing oscillation near 1.2 µm was observed at 77 K, slightly beyond 4.0 kA/cm2, in a hetero-isolation stripe laser with an active layer 1.6 µm thick.
Multiply-Charged Metal Ion Source for Cyclotron
Authors: Ikegami Kumio , Kageyama Tadashi , Kohno Isao
Published: November 2005

In order to accelerate metal ions in the IPCR 160 cm cyclotron, an ion source has been developed which produces multiply-charged metal ions such as Li2+, Li3+, Be3+ and B3+. The ion source is of the electron-bombarded hot-cathode type with a sputtering electrode installed in the anode of the source. The sputtering electrode is made of the material to be charged: LiF is used for Li ions, metallic Be for Be ions, and B2O3 and boron nitride for B ions. Using this metal ion source, 6Li2+, 7Li2+, Be3+, 10B3+ and 11B3+ ions were accelerated in the IPCR cyclotron and ion beam of sufficient intensity were extracted from the cyclotron.
X-Ray Diffraction Profile Analysis for the Determination of the Crystal Structure of BaTiO3
Authors: Tanaka Masahiro , Fujishita Hideshi , Shiozaki Yōichi , Sawaguchi Etsuro
Published: November 2005

The profile analysis method is applied to the X-ray powder diffraction pattern of tetragonal BaTiO3; a Si specimen is also examined as an initial test of the method. The accuracy with Si is nearly the same as that of the standard single crystal method. The result for BaTiO3 powder proves that the X-ray profile analysis method is quite useful for the determination of structures, especially when no single crystals are available or the conventional single crystal method is unsatisfactory because of experimental difficulties.
Electron Optical Conditions for the Formation of Structure Images of Silicon Oriented in (110)
Authors: Nishida Takahiko
Published: November 2005

The electron optical conditions for the high resolution structure image of silicon oriented in (110) are researched on the basis of the calculation of image contrasts using the multislice theory. Effects of various parameters such as crystal thickness, the amount of defocus, the size of objective aperture, chromatic aberration and misorientation of the crystal on the images are clarified. It is found that the optimum thickness giving the highest contrast image is about 130 Å and the optimum defocus appears periodically at this thickness with a width of ∼10 Å and with a period of ∼1600 Å for the spherical aberration coefficient, C
s=0.7 mm. The allowable fluctuation of defocus due to chromatic aberration is found to be ∼40 Å, and the allowable misorientation angle of a crystal is ∼2×10-3 rad.
Structural Change of Oxidation-Induced Frank Sessile Dislocation Loops in Silicon
Authors: Kawado Seiji
Published: November 2005

The conversion of Frank sessile loops to perfect dislocation loops in silicon during successive thermal oxidation has been studied by X-ray topography, chemical etching and transmission electron microscopy. Frank loops generated on any one of four {111} planes during the first oxidation are changed into perfect loops in the second oxidation process in three different ways. The temperature dependence of the conversion rate seems to follow a thermal activation process, the activation energy being about 2.4 eV. The rate is accelerated by deterioration in cleanliness of wafers and oxidizing atmosphere. According to the view that the conversion is caused by the nucleation and expansion of a pair of loops of Shockley partials inside a Frank loop, the generation of the Shockley partials is presumably attributable to the localized stress around impurity precipitates at the Frank partial.
Two-Pass Optical Second-Harmonic Generation
Authors: Umegaki Shinsuke
Published: November 2005

The two-pass optical second-harmonic generation is theoretically treated for analyzing the effects of the walk-off, the absorption in the nonlinear crystal and the beam radius of the fundamental laser. Computational results show the range of the crystal length where a higher second-harmonic power is obtained in the two-pass system than in the one-pass one.
Formation of Large Blisters on Rolled Mo Surface Bombarded with Hydrogen Ions
Authors: Okuda Shuichi , Imoto Shosuke
Published: November 2005

Relatively large blisters were observed on the surface of rolled plates of polycrystalline molybdenum bombarded with hydrogen ions at energies of 160 eV or greater. Some blisters have a skin thickness about 2 orders of magnitude larger than the projected range of implanted ions, thus being distinguished from those of usual radiation blistering. The formation of such large blisters depends on the texture of the metal specimen, and may be attributed to the high pressure gas produced by the recombination of hydrogen atoms at the site of the defects originating in the fabrication of the specimen.
A New Field-Effect Transistor with Selectively Doped GaAs/n-AlxGa1-xAs Heterojunctions
Authors: Mimura Takashi , Hiyamizu Satoshi , Fujii Toshio , Nanbu Kazuo
Published: November 2005

Studies of field-effect control of the high mobility electrons in MBE-grown selectively doped GaAs/n-Al
x
Ga1-x
As heterojunctions are described. Successful fabrication of a new field-effect transistor, called a high electron mobility transistor (HEMT), with extremely high-speed microwave capabilities is reported.
Tunneling Current in InGaAs and Optimum Design for InGaAs/InP Avalanche Photodiode
Authors: Ando Hiroaki , Kanbe Hiroshi , Ito Masanori , Kaneda Takao
Published: November 2005

Breakdown voltage and dark current density in p+n and n+p In0.53Ga0.47As diodes are compared with theoretical values taking the backward tunneling current into account. Predominant origin of dark current in an InGaAs diode is attributed to the tunneling current. Using these results, optimum design of an InGaAs/InP avalanche photodiode (APD) to obtain low dark current, high multiplication gain, high quantum efficiency and fast response is also discussed.
Population Inversion in Recombining Weakly Ionized Hydrogen Plasma
Authors: Furukane Utaro , Yamamoto Tetsuro
Published: November 2005

A new calculation method is presented, which is suitable for investigating a population inversion between the energy levels of weakly ionized hydrogen plasma in which atom-atom collision processes have to be considered. As an example, the plasma conditions required for inversion between energy levels of the principal quantum number 4 and 5 of hydrogen atom are calculated by this method. In contrast to the recombining hydrogen plasma with moderate temperature (k
T
e\gtrsim1 eV), it is shown that population inversion is possible in a larger range above the lower bound of the effective recombination rate of the plasma.
Rapid-Scan Autocorrelator for Monitoring cw Mode-Locked Dye Laser Pulses
Authors: Ishida Yuzo , Yajima Tatsuo , Tanaka Yuichi
Published: November 2005

A second-order autocorrelator operating at a high repetition rate of 25 Hz was developed for the measurement of the picosecond pulse width of a cw mode-locked dye laser. The simple system consists of a Michelson-like interferometer and an assembly of retardation plates of different thickness which are mounted on an optical chopper. The pulse width is instantaneously displayed on an oscilloscope. Using this instrument, pulses as short as 1.3 ps can easily and reproducibly be obtained from a synchronously-pumped rhodamine-6G dye laser, even though the pulse-width varies critically with cavity length and other laser parameters.
CVD Al2O3 Films on III-V Binary Semiconductors
Authors: Shinoda Yukinobu , Kobayashi Takeshi
Published: November 2005

Chemical vapor deposited Al2O3 films grown on various kinds of III-V compound semiconductor substrate were examined and compared with each other. The ion-beam etching technique was employed as a detection method of non-uniformity lurking inside the film. Dependence of the film quality on the substrate crystal was clearly found : Uniform film was obtained on GaSb. Fairly high density of non-uniformity was found in the films on InP, InSb, InAs and GaAs.
Reflection Electron Microscope Observations of Dislocations and Surface Structure Phase Transition on Clean (111) Silicon Surfaces
Authors: Osakabe Nobuyuki , Yagi Katsumichi , Honjo Goro
Published: November 2005

A recently reported surface study by means of ultra-high-vacuum reflection electron microscopy (Osakabe et al. : Surf. Sci. in press) was extended to further details of clean (111) silicon surfaces. A screw dislocation emergent at the surface was clearly identified as the place at which one surface step terminates with a characteristic line contrast. In the transformation between the (7×7) and (1×1) surface structures across 830°C, the surface steps act as nucleation sites : on cooling the (7×7) structure nucleates at the upper edge of the steps and grows along the upper terraces, while on heating the reversed process takes place.
Fluoride Glass Fiber for Infrared Transmission
Authors: Mitachi Seiko , Manabe Toyotaka
Published: November 2005

Fluoride glass fibers were drawn from the GdF3-BaF2-ZrF4 glass rod by a conventional fiber fabrication technique. The homogeneous glass rods were prepared with the composition 2≦GdF3≦7, 28≦BaF2≦38 and 58≦ZrF4≦69 (mol%) by casting in a brass mold. The transmission loss of the best fiber was as low as 0.48 dB/m, measured at 3.39 µm for a fiber several meters long ; further purification of starting materials should yield significant decreases in the transmission loss, approaching the intrinsic value.
Isothermal Capacitance Transient Spectroscopy for Determination of Deep Level Parameters
Authors: Okushi Hideyo , Tokumaru Yozo
Published: November 2005

A new measurement method for deep levels in semiconductors is proposed, by which the measurement of the transient change of capacitance is performed under an isothermal condition (Isothermal Capacitance Transient Spectroscopy). The method allows us to construct a precise measurement and analysis system by a programmable calculator. Computer simulation and experiment by the method in the case of Au-doped Si are demonstrated. It is shown that the method is one of useful tools for spectroscopic analysis of deep levels in semiconductors.
Czochralski Growth of Square Silicon Single Crystals
Authors: Kuroda Ekyo , Matsubara Sunao , Saitoh Tadashi
Published: November 2005

Square single crystal silicon ingots with 3-inch sides are grown by forming an essentially uniform temperature distribution around the growing ingots. The resistivity distribution pattern for wafers from these ingots is generally square. The square single crystals have etch pit densities of 1-2×103/cm2. The growth for square crystals is explained by a model in which supercooling occurs in the radial direction of the ingots.
Optical Waveguides along Both Sides of a Groove in Silicon
Authors: Kimura Mitsuteru , Hata Kiyomi , Miyamoto Toshihiko
Published: November 2005

New fabrication methods of waveguides with an transverse measurement of about 1 µm and of a Y junction using a simple photolithographic technique are proposed. The waveguides consist of a high refractive index plastic such as polystyrene filling up the concave sides of a groove produced in a Si wafer by means of an anisotropic etching technique. Propagation of a He-Ne laser beam through these waveguides with an transverse measurement of about 5 µm is demonstrated.
Observation of Si-2p Level Shift in Hydrogenated Amorphous Silicon by X-Ray Photoelectron Spectroscopy
Authors: Usami Katsuhisa , Shimada Toshikazu , Katayama Yoshifumi
Published: November 2005

The XPS spectra of hydrogenated amorphous silicon (a-Si: H) and amorphous silicon without hydrogen (a-Si) are studied in the Si-2p core level region as functions of in-situ heat treatments. The Si-2p binding energy in a-Si: H does not change until 400°C heating and shifts to the lower energy side by 0.15 eV after 500°C heat treatment where most of hydrogen incorporated evolves, while the Si-2p binding energy in a-Si without hydrogen remains unchanged by heat treatment up to 600°C, The results suggest that incorporated hydrogen affects not only Si atoms directly bonded to hydrogen but also the remote Si atoms in the Si–Si network.
Spatial Change of Rise Time of Spectral Line Intensities in Hollow Cathode Discharge Tube
Authors: Yamashita Masafumi , Kimura Muneyasu
Published: November 2005

The local dependence of the rise time of the emissive line intensities of Ne in a cylindrical hollow cathode has been measured as a step toward studying the mechanism of emission. Several new interesting results were observed: In a special range of gas pressure, the temporal change of the intensities at the central axis portion shows a clear initial peak enhancement and then a decrease to the stationary state. The rise time of the intensity at the central axis portion is always a few microseconds faster than the edge portion. The precision of the time resolution of our apparatus is qualitatively discussed.
Effect of the Shunt Capacitance on the ac Josephson Effect in Nb Point Contacts
Authors: Noguchi Takashi , Ohsawa Keishi , Morita Seizo , Mikoshiba Nobuo
Published: November 2005

The ac Josephson effects in Nb point contacts were measured using optically pumped sub-millimeter-wave laser. Laser-induced constant voltage steps (Shapiro steps) were observed on the dc I–V curves of the hysteretic junction as well as non-hysteretic junctions. We found that the height of the fundamental step normalized to the critical current at no irradiation in hysteretic junctions was considerably larger than that previously reported. The enhancement of the step observed can be explained by taking the effect of the shunt capacitance into consideration.
Contact Resistance Dependence on InGaAsP Layers Lattice-Matched to InP
Authors: Nakano Yoshinori , Takahashi Shin-ichi , Toyoshima Yoshio
Published: November 2005

The effect of composition on the contact resistance between AuZn alloy and p-type InGaAsP layers lattice-matched to InP has been investigated and it was found that a lower contact resistance could be obtained by decreasing the energy gap of the quaternary layer. This fact can be explained in terms of carrier tunnelling as a current transport mechanism.
LPE Growth and Luminescence of In1-xGaxPyAs1-y on (1, 0, 0) GaAs with Band-Gap Energy in Region of 1.569 eV≤Eg≤1.893 eV
Authors: Mukai Seiji , Matsuzaki Masatoshi , Shimada Jun'ichi
Published: November 2005

An LPE growth method of In1-x
Ga
x
P
y
As1-y
layers on (1, 0, 0) GaAs is described over a wide range of band-gap energy. Melt compositions for lattice-matched growth of these layers are given. Photoluminescence spectra of the layers are reported, and their spectral shape and luminescent-peak energies are discussed in comparison with In1-x
Ga
x
P
y
As1-y
grown on InP.
The Density of Localized States in Amorphous InxSe1-x Thin Films
Authors: Naito Hiroyoshi , Okuda Masahiro , Matsushita Tatsuhiko , Nakau Tanehiro
Published: November 2005

The field effect method has been used to determine the density of localized states in amorphous In
x
Se1-x
thin films for the range of the composition 0.05≤x≤0.4. This method provides a monotonic density distribution of localized states below the thermal equilibrium Fermi level for each specimen. Concerning the compositional dependence on the density of states, experimental results show that the density of states has a minimum value for the amorphous In0.2Se0.8 film and a maximum value for the amorphous In0.3Se0.7 film. These results may be explained by the random network model with the In-Se and Se-Se bonds.
Study of Photo-Induced Effect in Obliquely-Deposited Amorphous Ge-Se Films by XPS
Authors: Ueno Tokihiro , Odajima Akira
Published: November 2005

Amorphous GeSe, GeSe2 and GeSe3 films were investigated by XPS. Binding energies and chemical shifts of the 3d and 3p electrons of the constituent elements were measured. It was found that obliquely-deposited GeSe3 films contain four(Ge)-two(Se) fold and three(Ge)-three(Se) fold bondings, while normally-deposited films have the former type bonding alone. Photo-induced chemical shifts of obliquely-deposited GeSe3 films are attributable to a transformation from the four(Ge)-two(Se) fold bonds to the three(Ge)-three(Se) bonds. The mechanism of thephoto-induced effect is described.
Molecular Orbitals for Chemisorption of Sulfur on Copper
Authors: Adachi Hirohiko
Published: November 2005

Discrete variational Xα cluster calculations of S on Cu(001) surfaces have been carried out. Valence orbital levels, wave functions of bonding orbitals and charge densities have been investigated both for hollow-site (fourfold-site) and on-top-site chemisorptions. The results show that hollow-site chemisorption is more stable than on-top-site.
Emission Characteristics for <100>, <110> and <111> LaB6 Cathodes
Authors: Takigawa Tadahiro , Yoshii Shintaro , Sasaki Isao , Motoyama Kakuju , Meguro Takashi
Published: November 2005

Characteristics for electron beam emitted from <100>, <110> and <111> axial orientation LaB6 cathodes after 100 hours of aging were studied. It is inferred from the emission pattern and cross-over image that electrons are emitted to a great extent from the top surface for the <100> cathode and mainly from the conical surface for <110> and <111> cathodes at a bias voltage that gives maximum brightness. This inference clearly explains the electron beam characteristics such as brightness, emission angle and total beam current.
Thermal Oxidation of Silicon
Authors: Karube Norio , Yamamoto Kakuji , Kamiyama Masahide
Published: November 2005

Some experiments concerning the mechanism of the thermal oxidation of silicon, are described. Experiments with a radioactive tracer using the sectioning technique indicate strongly that during the thermal oxidation of silicon the diffusion of oxygen is responsible for the growth of the oxide film. The same technique is applied to the study of the oxidation of copper. A physical picture for the oxidation of metals in general is derived from these series of experiments.
Penetration curve for the diffusion of oxygen during the oxidation of silicon is obtained from infrared absorption measurements using the sectioning technique.
The Propagation of Sound Waves in a Rectangular Duct with Porous Material
Authors: Kajiyama Masato
Published: November 2005

(i) A (0,0) mode of the sound wave is excited in a duct with its rear end closed with a thick rockwool blanket. The characteristic impedance and propagation constants of the rockwool are determined by the standing wave method. (ii) (0,0) and (1,0) mode travelling waves are excited in a duct with its walls lined with rockwool blankets and the propagation constants of the duct are determined from measurements. (iii) The following quantities are calculated employing the above-mentioned data, for (0,0) and (1,0) waves: (1) the variations of both the pressure and particle velocity in a cross section of the duct; (2) energy flow density; (3) stream lines of energy; (4) the surface of an equal phase (i. e.wave front). Some of the calculated values showed fairly good agreement with the observed results.
Microwave Observations of Carrier Behaviors in “Oscillistors”
Authors: Misawa Toshio , Yamada Toshiyuki
Published: November 2005

Observations of carrier behaviors in germanium “oscillistors” by means of 24Gc microwave reflection have revealed that the observed oscillations in current and voltage are accompanied by carrier density waves which propagate and rotate in certain directions, as Glicksman had predicted. Observed directions of propagation and rotation agree with his prediction inptype and intrinsic samples, but not inntype ones. It is shown that the difference between hole and electron densities in semiconductor is responsible for this disagreement, and his calculation is modified so as to be applicable to semiconductor plasma. It has also been found that the total carrier number at a given cross section also oscillates. The ac current and voltage hitherto observed are ascribed to this carrier number oscillation. Deviations from circular symmetry are shown, on the basis of a qualitative discussion, to account for this oscillation.
Diffusion of Impurities in the Semiconductor Melt II. Dynamical Analysis of Impurity Redistribution in the Melting Process
Authors: Kodera Hiroshi , Tauchi Shoji
Published: November 2005

An analysis is given on the redistribution of solute in the semiconductor melt during the melting process of a crystal which is in contact with the melt. In contrast to a previous work where an assumption was made concerning the impurity distribution in the melt just when the melting process was finished, the existence of the solute diffusion layer directly under the crystal is assumed throughout the whole process. After the melting process, impurities in the melt are made to diffuse into the crystal. Analytical formula for impurity distribution in the crystal is given in a convenient form for the direct comparison with experiments.
Experimental Studies on the Properties of the Air Gap Spark Chamber
Authors: Matsukawa Yoshinobu
Published: November 2005

An investigation on an air gap spark chamber under the atmospheric pressure, especially on its efficiency for detecting multiple tracks, is described in this paper. The particle trajectory in a gap is determined within a probable error of 0.5 mm with three spark gaps which are separated from one another by 10 cm. The maximum efficiency for detecting a single track obtained in this study is about 95%. The spurious sparks which are induced by the other spark are prevented by means of isolating optically each gap from others.
Internal Stress and Electrical Resistivity of Evaporated Antimony Films
Authors: Horikoshi Hisashi , Tamura Noriko
Published: November 2005

Internal stress and electrical resistivity are simultaneously determined for evaporated antimony films during and after evaporation. At first antimony is deposited in the amorphous state. When a critical thickness is reached, the film begins to cristallize giving rise to large intrinsic stress. The dependence of stress upon film thickness, evaporation rate and substrate temperature is experimentally studied. The results can be explained by variation in the effective critical thickness,deff, which is defined as the film thickness at which crystallization of the antimony film proceeds most vigorously.
Operating Characteristics of Large Diameter Photomultipliers I. Scintillation-Spectrometric Performance
Authors: Iinuma Takeshi A.
Published: November 2005

The scintillation-spectrometric performances for two types of 7 in. diameter photomultipliers (20th century VMP/11/170 and E.M.I. 9623) were investigated as a function of photocathode-first dynode voltage. The two types of tubes showed very different characteristics from each other that are due to differences in the electron-optical structures of photocathode-first dynode system. (1) VMP/11/170 tubes showed the minimal spread in the pulse height distribution at 325 V, though the gain was not maximal. (2) The optimal voltages for 9623 tubes were also determined. The mesh focusing electrode showed strange characteristics as a focusing electrode which may be explained as an additional dynode. (3) The statistical analysis of the results with VMP/11/170 tubes indicated that the relative variance of the number of secondary electrons emitted from dynodes was changing with the energy of primary electrons.
Analysis of Adjacent Elements in X-ray Spectroscopy with Radioisotopes
Authors: Tanemura Takashi
Published: November 2005

X-ray fluorescence analysis was carried out with H3/Zr and Pm147/Al as primary x-ray sources. For spectro-analysis, pulse analysis with proportional counter and electronic pulse height analyser or x-ray filter is applied. In the He flow small specimen chamber, light elements as Na, Mg, Al and Si were detected. Al2O3and SiO2mixtures were analysed with Al filter. Pulse analysis technique was applied to three element system, Cr2O3-Fe2O3-NiO mixtures, and effects of overlapped spectra were examined. Accuracies of the analysis are 0.3% for 10–20% Cr2O3, 1% for 70–100% Fe2O3and 2% for 5–10% NiO in a counting time of one minute.
Calculation of the Secondary Electron Spectrum at the Boundary Layer
Authors: Shiomi Naoko , Higashimura Takenobu
Published: November 2005

The slowing down spectrum of secondary electron caused by gamma rays is analyzed by the segment theory in an infinite medium.
An approximate method in a semi-infinite medium is shown for obtaining the spectrum of the electron crossing the boundary. A practical calculation is performed for the Aluminum slab irradiated by Co60 gamma rays and the calculated spectrum of impinging electrons is compared with the experimental data with a sufficient consistency.
The Effect of Uniaxial Stress on Ge p-n Junctions with Various Doping Densities
Authors: Imai Tetsuji
Published: November 2005

When p-n junctions with various doping densities are subjected to uniaxial stress perpendicular to the (111) junction plane, an extreme increase in the excess current with stress is found, in contrast with a small increase in the Esaki current. This change in the excess current of Esaki diodes is mainly ascribed to properties of heavily doped p-n junctions regardless of the existence of the Esaki characteristics. The experiments indicate that the stress sensitivity of p-n junctions becomes larger as the doping density becomes larger.
Structure Cristalline du Dioxyde de Niobium
Authors: Terao Nobuzo
Published: November 2005

Crystal Structure of Niobium Dioxide.
The X-ray diffraction results on NbO2, prepared by heating in vacuo a mixture of powders of Nb2O5 and Nb, confirm the previous electron diffraction results obtained with thin films. Besides the strong reflections attributed to a rutile lattice structure, a great number of additional weak reflections were observed. Following this observation, the structure analysis has been undertaken by calculating the structure factors on various models. Three types of possible structures derived from the rutile structure were investigated: a superlattice, a defective lattice, and an interstitial lattice structure, respectively. It is concluded that there is only one possible structure modification of a superlattice type. Some of the O-Nb-O molecules in the rutile structure change their molecular orientation on the (001) planes whose stacking sequence is expressed by αβα' βα…
Impurity Substructure in Zinc Crystal Grown from the Melt
Authors: Kiritani Michio , Yoshida Sho , Mikuriya Nobuo
Published: November 2005

The impurity substructure in zinc single crystals grown from the melt is studied experimentally. Geometrical shapes of the substructure are classified into three types according to the crystallographic growth direction. Sizes of these impurity substructures vary with growth speed and impurity content. It is concluded that diffusion of impurity atoms in the liquid plays the essential role on the formation of the substructure; the variation of impurity substructure are qualitatively explained by the impurity diffusion near the solid-liquid interface. It is also observed that large angle grain boundaries near the liquid-solid interface have the same character as the impurity substructure boundaries.
Switching Behaviors of Electrodeposited Nickel-Iron Thin Films
Authors: Uehara Yasuo
Published: November 2005

In this paper are described the experimental results of magnetic flux reversal by partial switching in 80Ni–20Fe thin films electrodeposited onto copper plates. The flux reversal was realized by means of pulsive magnetic fields, whose rise time are 10 nsec and 1 nsec. The output of switching was observed with a pickup wire fixed perpendicular to a driving wire.
The dependence of the switching time and the output voltage on driving field intensities and on the direction of the field relative to the magnetic easy axis were studied. A possibility of high-speed switching nearly in 1 nsec has been proved, which is equivalent to that of films evaporated onto glass substrates. It has also been found from the studies of the switching characteristics of electrodeposited films from 2100Å up to 16800Å thick that there exist an optimal film thickness which give a high level output and a fast switching, and that the optimal thickness depends upon the rise time of driving pulse. The effect of eddy current damping on the switching phenomenon is also discussed.
An Electron Microscope Study on Fine Metal Particles Prepared by Evaporation in Argon Gas at Low Pressure
Authors: Kimoto Kazuo , Kamiya Yoshihiro , Nonoyama Minoru , Uyeda Ryozi
Published: November 2005

Fine particles of various metals (Mg, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Sn, Au, Pb and Bi) were prepared by evaporation in argon gas at low pressure. The evaporation was carried out in an ordinary vacuum evaporation unit using a tungsten wire basket heater, after introducing the gas into the vacuum chamber. The average particle size was controlled by changing the pressure of the argon. Particle diameter varied from about one hundred Angstoms at 1 mm Hg to a few tenths of a micron at 30 mm Hg. It was proved by electron diffraction that the particles of all the metals (except Pb) were not seriously oxidized in the air. Electron micrographs showed well defined crystal habits for some metals, e.g. hexagonal plates for magnesium and cubes for chromium. Remarkable “necklace-like arrangements” were observed for particles of the ferromagnetic metals. Many electron micrographs and diffraction patterns are reproduced to show the size, shape, arrangement and state of oxidation of the particles.
Pulse Propagation Method for Line-Shape Parameter Analysis in a Slightly-Saturated Laser Amplifier: Application to the Xenon 3.5 µm Line
Authors: Sato Heihachi , Gamo Hideya
Published: November 2005

Applying a quasi-CW approximation for the rate equations with density matrix elements, the formulae for wide optical resonant-pulse propagation are derived in a partially homogeneously broadened, saturated gain medium. From the theoretical formulae of the pulse intensity, pulse duration and pulse delay time as a function of plasma length and these experimental results for various input intensities, we can determine the saturation intensity, the Lorentzian linewidth, the Doppler linewidth and the gain parameter by using the quadratic Taylor series expansion in the theory and the least-squares fit to the experimental results. This method is applied to the xenon 3.5 µm transition, showing that the parameters obtained are consistent with those obtained by the CW method within a small difference.
Epitaxial Growth of Aluminum Nitride on Sapphire Using Metalorganic Chemical Vapor Deposition
Authors: Morita Mizuho , Uesugi Norihiko , Isogai Seiji , Tsubouchi Kazuo , Mikoshiba Nobuo
Published: November 2005

Epitaxial aluminum nitride (AlN) films were grown on the basal planes of sapphire substrates using metalorganic chemical vapor deposition (MO-CVD), and the following results were obtained. (1) The substrate temperature and the trimethylaluminum (TMA) concentration dependences of the growth rate suggested that the growth process is limited by mass transport. (2) The crystalline perfection of epitaxial films is strongly affected not only by the substrate temperature but also by the gas flow pattern. (3) Single-crystal AlN films which include no misoriented grains can be grown epitaxially at ∼1200°C under carefully-controlled gas flow patterns. (4) Crystalline imperfection is caused mainly by (1 1̄01)-oriented grains which correspond to the hillocks observed in the surface morphology.
Ion Temperature Measurements of Turbulently Heated Tokamak Plasma by Doppler-Broadening of Visible Lines in TRIAM-1
Authors: Hiraki Naoji , Nakamura Kazuo , Toi Kazuo , Itoh Satoshi
Published: November 2005

In the turbulent heating experiment of the high-field tokamak TRIAM-1, the bulk ion heating shown by the neutral energy analyzer measurement is confirmed by the Doppler broadening measurement of visible lines. The increasing rate and decay time of the Doppler ion temperature are almost the same as those derived from the neutral energy analyzer measurement.
From both methods of ion temperature measurements, it is shown that the ion temperature has a parabolic profile within 50 µs after the application of the heating pulse.
Li In- and Out-Diffusion Processes in LiNbO3
Authors: Fukuma Masaharu , Noda Juichi
Published: November 2005

Li in-diffusion and out-diffusion processes in LiNbO3 crystals, when treated in Li2CO3 powder, were investigated through second harmonic generation phase matching temperature measurement using a YAG laser. After annealing at 600°C for more than 52 hours in Li2CO3, in-diffused Li ions caused a slight decrease in the ordinary refractive index near the surface of the polished LiNbO3 substrate. These samples showed a large decrease in extraordinary refractive index after being annealed at 1050°C in air. Wrapping the LiNbO3 substrate in platinum foil to prevent direct contact with the Li2CO3 powder was found to be a successful method to suppress Li out-diffusion without surface degradation.
Resonant Coupling of the Guided Mode with Surface Plasma Mode in a Stratified Structure Containing a Metal-Clad Dielectric-Film Waveguide Having Low-Refractive-Index Buffer Layer
Authors: Kitajima Hiroe
Published: November 2005

When the guided mode in a dielectric film waveguide couples with the surface plasma mode, the dispersion of the coupled guided mode, which depends on the thickness of buffer layer between the film waveguide and metal substrate, exhibits anomalous characteristics, and therefore the film waveguide supports even and odd guided modes. However, owing to the collision loss of the free electrons, the phase velocities of these modes degenerate and the dispersion becomes zero in the vicinity of the surface plasma mode, with an optimum buffer layer thickness. When the degenerate modes are optically excited through a prism region, this stratified structure exhibits double tuned absorption characteristics with a flat absorption peak. These resonant coupling phenomena were studied.
Current Dependency of the Noise in Space-Charge-Limited Solid-State Diodes
Authors: Takagi Keiji , Kaku Yasuhiko
Published: November 2005

Experimental evidence shows that the noise current is proportional to 1/2 power of the current I in the limiting white noise region and to 3/2 power of current I in the 1/f noise region for laboratory-made SCL diodes. The noise analysis is carried out as for a FET. The limiting white noise level agrees quantitatively with the thermal noise level analyzed in this paper, while the 1/f noise agrees qualitatively with the analytical result derived from Hooge's empirical expression.
Measurement of Electrical Resistivity of CVD-BN Passivation Film from Gate Charge Decay Time of a MOS Transistor
Authors: Kim Chol , Shono Katsufusa
Published: November 2005

The electrical resistivity of a passivation film used on integrated circuits can be determined from the gate charge decay time of a MOS transistor, where the edge wall of the gate insulator films is covered with a passivation film. For example, we determined the electrical resistivity of CVD-BN (boron nitride), which can be used as a diffusion source of boron into Si in the fabrication process and as a surface passivation of the edge wall of gate insulator films to improve device reliability. The electrical resistivity obtained is between 1011 and 1015 ohm-cm depending on the deposition temperature in the range of 400 to 550°C, although heat treatment at 720°C for Si3N4 deposition and at 1200°C for boron diffusion were also carried out during the fabrication of a test p-MOS transistor.