bluuebunny/crossref_metadata_2025 huggingface dataset:
Fundamentals of Mutual Conversion of Electrical Energy and Mechanical Energy by Simultaneously Ferroelectric and Ferroelastic Crystals
Authors: Aizu Kêitsiro
Published: November 2005

The concept “ferroelasticity” is analogous to “ferroelectricity,” mechanical strain and stress in the former corresponding to electric polarization and field in the latter. Crystals which are both ferroelectric and ferroelastic can (in principle) be applied to mutual conversion of electrical energy and mechanical energy. A thermodynamic investigation is made into basic problems in this application–domain structure of the crystal element, optimum conditions for conversion, rate of conversion, and others; here the crystal concerned is assumed to be such that the ferroelasticity may phenomenologically be regarded as induced by the ferroelectricity through piezoelectric coupling or, oppositely, such that the ferroelectricity may phenomenologically be regarded as induced by the ferroelasticity through piezoelectric coupling. For the sake of comparison, the case is also considered where a typical, simple piezoelectric crystal is used instead.
Theory of the Conduction of Heat in Foamed Plastics II. Square Array of Cylindrical Cell Gas
Authors: Oka Syoten , Yamane Kuniko
Published: November 2005

The conductivity of a plastic foam with a square array of cylindrical cell gas is treated theoretically. Since the approximate formula obtained by Lord Rayleigh is applicable only for small values of the volume fraction λ of cell gas, we have developed a general theory of the conductivity of heat of such a plastic foam which will be valid in a wider range of λ. The effective conductivity of the plastic foam is shown to be a function of λ and σ, which is the ratio of the conductivity of the cell wall to that of the cell gas. In order to calculate the effective conductivity as functions of λ and σ, it is necessary to solve a system of linear equations in an infinite number of variables. The conductivity has been calculated approximately for various values of λ and σ with the electronic computer.
Effect of Heat Treatment on Gallium Arsenide Crystals II. Properties of Crystals Heat-Treated in Chalcogen Vapor
Authors: Toyama Masaharu , Ikoma Hideaki
Published: November 2005

Melt-grown n-GaAs crystals were heat-treated in a sulfur vapor or a mixed vapor of sulfur and arsenic, and their electrical properties were investigated. The chalcogen vapor appeared to suppress thermal conversion of crystal from n-type to p-type conductivity. The crystals showed two donor levels with ionization energies of nearly 0.15 eV and 0.002 eV, respectively. Concentration of the 0.15 eV deep donor was lower for the samples heat-treated at higher temperatures and in a vapor of lower sulfur content, and tended to decrease with increase in acceptor concentration. The deep donor was thus attributed to a complex center, including arsenic vacancies, and its dissociation energy was estimated to be nearly 1.5 eV. The product of the concentration and the scattering cross section of space-charge region, N

s

A, was found to increase in proportion to acceptor concentration. This fact indicates that the space-charge region arises where shallow donors are strongly compensated for with acceptors.
Self-Modulation and Picosecond-Pulse Generation by Stimulated Raman Scattering
Authors: Shimoda Koichi
Published: November 2005

The regular structure in frequency broadening spectrum of the self-trapped laser and Raman radiations is produced by the phase-modulation of light waves propagating in the filament with intensity-dependent index of refraction. A quantum-mechanical calculation of double quantum transition in a three-level system is shown to explain the process of self-modulation and the production of picosecond pulses in the Raman process.
Coherent coupling of the laser and the Stokes waves produces mutual modulation of large amplitude, if the optical field is strong and the vibrational relaxation time is long. Numerical evaluation for CS2 gives a modulation frequency of about 1011 Hz, when an optical power of 10 kW is trapped in a filament of 2 µm radius.
Besides, the effect of self-modulation on the spatial distribution of anti-Stokes emission along the filament is discussed and shown to agree with the experimental results observed by Stoicheff and his co-workers.
Excitation of Fabry-Perot Resonator III. Wave Incidence through Semi-Transparent Mirror
Authors: Yoshida Yasuo , Ogura Hisanao , Ikenoue Jun-ichi
Published: November 2005

The excitation problem is theoretically analysed for the plane wave incident through a semi-transparent mirror of the resonator. The authors' foregoing analysis of the forced excitation of a resonator with perfect mirrors is extended in this paper, using the additional boundary condition across a dielectric mirror. The formulation is generally made for an oblique incidence of plane wave on the dielectric mirror. The analysis in the case of free oscillation yields the one-transit loss which equals the ordinary diffraction loss plus half the transmission coefficient. For the normal incidence input characteristics and amplitude and phase distributions of the field are computed for some transmission coefficients of the mirror. Similar computations are made approximately for the oblique incidence and the field distributions are represented as the contour maps, where rotationally asymmetric modes are more excited as the incident angle increases.
Measurements of Phase Bunching in Electron Linacs by RF Deflector
Authors: Toda Tetsuo , Irie Koichi , Nemoto Yoshiaki
Published: November 2005

A method for measuring directly phase distribution of electron bunch in linacs with a high phase resolution is presented.
A bunched beam is introduced into an RF deflector of travelling wave type, which is synchronously excited with the same frequency as that of the linac. Deflection of electrons corresponds to their phase in the deflecting field. Electrons of near zero phase pass through the narrow slit placed on a line of the deflector. By means of a phase shifter, which controls input RF phase, the phase of the bunch as to the deflecting field is shifted and phase spread of the bunch can be measured.
Principle of the RF deflector used in this measurement is described fully. Phase resolution is discussed in detail and it is shown that the phase resolution of a few degrees is obtainable. Results of measurements are also reported.
Large Signal Analysis of Read Diodes
Authors: Matsumura Masakiyo
Published: November 2005

This paper presents the results of numerical and analytical calculation of large signal properties of Read diodes. The results indicate that (i) threshold current density is proportional to the square of the oscillation frequency and that (ii) dc current density that causes microwave power saturation is proportional to oscillation frequency. It is elucidated that the optimum values of dc current density and ac voltage are determined mainly by the field distribution in the drift region. The optimum field profile of Read diode differs from the profile proposed by Read and resembles the profile of p-n-n
+ diode.
Effect of Depolarization Field on Electromechanical Properties of Piezoelectric Semiconductors (Theory)
Authors: Ogawa Tomoya
Published: November 2005

The electromechanical properties of piezoelectric semiconductors are treated taking the generalized depolarization factor, in which the corrections due to the leakage of electrical flux from the specimen is included, into account. The stress-strain relations analytically obtained include the generalized depolarization factor.
Effect of Depolarization Field on Electro-Elastic Properties of Photoconductive CdS Crystals (Experimental)
Authors: Ogawa Tomoya , Kojima Akira , Makino Tadayori
Published: November 2005

The sound velocity and mechanical loss of photoconductive CdS crystals are measured by the composite-bar method. The experimental results are analyzed by the stress-strain relation, which has been obtained previously by using the depolarization factor. The depolarization factors obtained by the elastic data are in mood agreement with the depolarization factor obtained from Bozorth-Chapin's data.
Fluctuation Distribution of Collimated and Focused Gaussian Beams Propagated through a Random Medium
Authors: Asakura Toshimitsu , Kinoshita Yasuaki
Published: November 2005

Three-dimensional distributions of the log-amplitude and phase fluctuations of a gaussian beam propagating through a randomly inhomogeneous medium are studied by evaluating their mean-square values. Diagrams are given of the lines of equal fluctuations of normalized log amplitude and phase for a collimated beam and a focused beam. The dependence of the three-dimensional fluctuation distribution upon the beam shape as functions of the beam radius and the focal length is discussed.
Phase Analyzer of Bunched Electron Beam
Authors: Takeda Yasutsugu , Matsui Isao
Published: November 2005

A method is proposed for analyzing a phase distribution of electrons in a bunched beam. An electron beam from a buncher is led into a re-entrant cavity, in which the beam is deflected at a gap by a transverse electric field of the same frequency with that of the buncher. The deflection angle of electrons corresponds to their phases in the bunched beam; consequently, if electron collectors are set at different deflection angles, their output simulates the phase distribution of the electrons.
A model experiment has been tried with a pre-buncher of a linac. The results are consistent with one-dimensional ballistic theory. When the pre-buncher was attached to a 6 MeV linac, the 45% increase of the output current was observed in good accordance with the estimation from the experimental phase-analysis.
Thickness Fringes of Complicated Profiles in Electron Micrographs of Magnesium Oxide Wedge Crystals
Authors: Takakashi Hidewo
Published: November 2005

Thickness fringes from single crystals of magnesium oxide were taken at 100 kV, 350 kV and 500 kV. By the use of a tilting stage, the direction of the incident beam was adjusted nearly parallel to the [01̄1] direction where many diffracted beams were excited and the complicated thickness fringes were produced. Their profiles and spacings were studied systematically. It was proved that the profiles become more complicated at higher voltages and that spacings are roughly in agreement with those calculated by using Bethe's second approximation.
On the Initial Stage of the Reduction Growth of Iron Whiskers
Authors: Tino Yosiaki , Mukoyama Etsuzo
Published: November 2005

The initial stage of the growth of iron whiskers was investigated using the Brenner method of the hydrogen reduction of ferrous chloride. A number of micro-crystals were formed on a fused quartz substrate, and their growth was followed. It was found that the growth of a whisker crystal did not always occur around a single axial dislocation, but took place as the result of the coalescence of several micro-crystals existing in a very narrow range. The reason why a perfect or nearly perfect crystal can be grown upon such a superposition of a number of nuclear crystals was explored experimentally, and then, a model of the possible mechanism was offered.
Enhanced Carrier Diffusion Associated with the Instability in Germanium Slice
Authors: Miyazaki Kazuhiko , Yamaguchi Jiro
Published: November 2005

Enhanced carrier diffusion associated with the density wave instability due to the gradient of carrier density in germanium slice was estimated at 77°K from the observations of (1) the distribution of carrier density along the direction of the thickness of the slice in the transverse magnetic field and (2) the transient time necessary for the decrease of the gradient of carrier density. The results show that when the instability occurs, the ambipolar diffusion constantDaof hot carriers becomes very large,i.e.,Da∼105cm2/sec (at 700 V/cm) which is larger about an order of magnitude than that before the instability occurs. The phenomenon is discussed in conjunction with the current oscillation (wherein microwave emission was also observed) in germanium slice, as well as the frequency response of the devices relative to the magnetic barrier layer effect.
Preparation and Electroluminescent Properties of p-n Junctions in Cd1-xMgxTe
Authors: Yamamoto Ryoichi , Itoh Kohji
Published: November 2005

Solid solutions of MgTe and CdTe were prepared throughout the range 0∼0.35 mole fraction MgTe. P-n junctions were formed from CdTe, Cd0.8Mg0.2Te and Cd0.65Mg0.35Te by diffusing P under Cd atmosphere for 10 to 72 hours and electroluminescent properties were investigated at room temperature.
The diode with x=0.35 emitted visible red light (∼6800 Å) with external quantum efficiency of 2×10-6 for 10 mA at 300°K. The emission spectra of Cd1-x
Mg
x
Te diodes (x\neweq0) are similar to the spectra due to Schoen-Klasens type transition as supposed in CdTe diodes. Capacitance measurements, current-voltage characteristics and transient effect measurements imply that, at high current density (∼100 A/cm2), diffusion current rather than the recombination current in the space-charge region relates to radiative recombination.
Effects of Oxygen on the Electron Current from a Heated Tungsten Field Emission Tip
Authors: Takai Munezo , Matsuda Tetsuro , Sato Kiko , Niu Hirohiko
Published: November 2005

The emission current from a tungsten tip was measured as a function of O2 pressure (9.4×10-11∼3.9×10-9 Torr) and of tip temperature (1170∼1530°K). Following results have been shown: (1) With the elapse of time, a sequence of a minimum and a maximum appears in the emission current. (2) The minimum and the maximum decrease with increase in O2 pressure. (3) The maximum decreases as the tip temperature is lowered or raised from 1290°K. (4) The time t
0 at which the maximum appears decreases as the O2 pressure p increases. Linear relations hold between log
p and log
t
0; the slope of the straight line decreases with increase in the tip temperature.
It is shown that a combined consideration of O2 adsorption and build-up of tungsten oxides may account for the results.
Acoustic Relaxations in Toluene and Alcohols in the Frequency Range of 10 to 300 kHz Measured by the Resonance Reverberation Method
Authors: Ohsawa Toshihiko , Wada Yasaku
Published: November 2005

The acoustic absorption in toluene at frequencies 10 to 300 kHz is measured by the improved resonance reverberation method. The relaxation is found around 100 kHz (20°C). The relaxation strength increases and the relaxation frequency shifts toward high with increasing temperature. The relaxation is assigned to the coupling of translational motion of molecules with intramolecular vibration of C-H stretching in the methyl group. A good agreement between experiment and theory is obtained in the relaxation strength over covered temperatures.
The absorption coefficient of acoustic waves in n-BuOH, i-BuOH and t-BuOH is measured by the same technique as in toluene. The relaxation is observed around 30 kHz (n-BuOH), 20 kHz (i-BuOH), and below 10 kHz (t-BuOH) at 30°C. The activation energy is 8.7 and 9.4 kcal/mole for n-BuOH and i-BuOH, respectively. The relaxation strength decreases with increasing temperature. The relaxation is interpreted in terms of the reaction between associated complexes, cyclic polymer and cyclic dimers.
A Simplified Method for Calculation of Strain Dependence of Internal Friction in Transverse Vibrations
Authors: Asano Shigeru
Published: November 2005

Damping phenomena in higher modes of free-free transverse vibration are analysed and tire effects of the distribution of the vibrational strain on the apparent internal friction are treated quantitatively. The functional relation of the observed internal friction with the maximum strain amplitude or the maximum displacement amplitude is different when different mode of vibration is used. A simplified method for finding the true strain amplitude dependence of the internal friction is presented where the average strain amplitude is used as an experimental variable. It is suggested that the amplitude-dependent part of the internal friction can be dependent on the frequency of the vibration.
Preparation of Fine Metal Particles by the Gas Evaporation Method with Plasma Jet Flame
Authors: Wada Nobuhiko
Published: November 2005

Fine particles prepared by means of evaporation in inert gas have been expected to show various interesting physical or chemical properties, By the conventional method of heating by tungsten wire, only ten milligrams of particles were produced in one cycle of evaporation. In the present experiment a plasma jet flame with helium gas is used for heating and a gram of particles were produced in five minutes continuously. The produced particles of Fe-Co-Ni alloy are examined by electron-microscope and a X-ray diffractometer. The crystal structure, oxidation, lattice imperfection and sizes of the particles are discussed.
Superconducting Tunnelling in Metal-Semiconductor Junctions
Authors: Tsuda Nobuo
Published: November 2005

Superconducting tunnelling effects were observed for mechanically contacted Nb–Si, Pb–Si, and Nb–GaAs junctions. The I–V curves of Nb–Si junctions largely deviate from the usual BCS curve. Deviations for Nb–GaAs and Pb–Si junctions are much smaller than that for a Nb–Si junction. This large deviation is explained by the uniformly distributed surface states on the boundary.
The upper critical fields H

c2 and H

c3 of the junctions are much larger than those of a bulk niobium.
Effect of Thermal Treatment in Cd or Se Atmosphere on Electrical Properties of CdSe
Authors: Hung Ming-Pan , Ohashi Nobumitsu , Igaki Kenzo
Published: November 2005

CdSe single crystals grown by the Prior method were treated in a broad range of Cd or Se vapor pressures and quenched to room temperature. The Hall coefficients and electrical resistivities of specimens were determined between room temperature and liquid nitrogen temperature. Effect of thermal treatment in metal or chalcogen vapor on electrical properties of CdSe was examined as a function of the vapor pressure. The result shows that electron concentration of CdSe prepared from 6-nine Cd and 5-nine Se does not depend on Cd vapor pressure but, it seems to depend on Se vapor pressure. On the contrary, electron concentration of CdSe prepared from 5-nine Cd and Se seems to vary as P

C
d

1/3. Dependence of resistivity on P

C
d
and P

S
e
2
is also reported.
Observation of Surface Phenomena of Rhenium by F.E.M. and F.I.M.
Authors: Kuroda Tsukasa
Published: November 2005

Clean and smooth surface is usually obtained by the field-evaporation in field-ion microscope. The state of the surface obtained in this way is different from that obtained by annealing. By annealing, the chemical potential of the surface which is mainly controlled by the migration energy of surface atoms would become minimum.
The effect of the applied high electric field should be taken into consideration in the study of adsorption with the field emission and field ion microscopes. The adsorbed atoms with atomic polarization are largely influenced by the tangential component of the electric field.
By the adsorption of carbon monoxide or oxygen, the field evaporation voltage decreased for tungsten, molybdenum and iridium but didn't for rhenium. This fact and the “build-up” phenomenon of alkali-carbonyl would show that the carbon monoxide adsorbs weakly and like Re←\oversetC\undersetO\interleave on rhenium.
Thermal Etching of NaF Cleavages
Authors: Patel A. R , Chaudhari R. M.
Published: November 2005

Freshly cleaved surfaces of sodium fluoride have been thermally etched in the range of temperature between 860°C and 930°C for the required time. The formation of circularly terraced pits has been discussed. The topography of thermal etch patterns is studied by multiple beam interferometry. Interaction of circular etch fronts from the point of nucleation of two or more dislocations is illustrated. Under controlled conditions of thermal etching, in addition to the thermal etch pits, spiral structures have been observed. It is conjectured that these spirals might have been formed as explained by Lang (1957). It is conjectured that the etch patterns appearing similar to the pattern observed at the Frank-Read sources might have been formed due to a pair of dislocations of opposite sign.
Current Saturation in GaAs Induced by Sound Amplification
Authors: Tsuji Mikio , Inoue Seiichirou
Published: November 2005

A nonlinear theory is presented of the current saturation in GaAs induced by the amplification of thermal phonons due to the piezoelectric coupling between the conduction electrons and the sound waves. A linear amplification coefficient obtained classically is used. An infinite growth of the thermal phonons to be amplified is suppressed by the nonlinear term (three-phonon process) due to the usual lattice anharmonicity, not due to the so-called Hutson mechanism responsible for the current saturation in CdS. The calculation shows that the current saturation becomes complete as the electron concentration becomes large. The results are compared with the experiment of Leroux-Hugon.
Electroluminescences of Zn-diffused GaP Diodes and Their Electrical Characteristics
Authors: Miyauchi Takeshi , Sonomura Hajimu , Yamamoto Nobuyuki
Published: November 2005

Electroluminescences and electrical characteristics were investigated concerning three kinds of Zn-diffused GaP diodes prepared from undoped, oxygen-free and oxygen-doped n-type crystals. Experiments have shown that the so-called red luminescence is closely related to the impurity oxygen, which is introduced into the crystals from quartz container during fabrication.
At low temperatures below 100°K, all the diodes exhibited a breakdown phenomenon associated with negative resistance, and at the same time, a new orange luminescence. Both these phenomena are considered to be correlated closely with the impurity band conduction. The orange luminescence may be due to the transition between the impurity bands (the donor band and the acceptor band), and the breakdown may be caused by the impact ionization of electrons and holes of the impurity bands into the conduction band and the valence band.
Electrical and Magnetic Properties of Cu3Se2 and Some Related Compounds
Authors: Okamoto Kimihiko , Kawai Shichio , Kiriyama Ryôiti
Published: November 2005

The electrical conductivity and magnetic susceptibility of binary compounds CuxSe (x=2.0, 1.8, 1.5, 1.0 and 0.5) and CuxS (x=1.8 and 1.0) were studied over the temperature range from -150°C to 150°C. These compounds are near metallic conductors with resistivities of 100 to 6000µΩ·cm. It is found that Cu3Se2 may be antiferromagnetic, while the others are diamagnetic or weakly paramagnetic. A qualitative discussion is presented on the basis of the valencies of constituents and coordination configurations in order to explain the physical properties of these substances.
Interface Characteristics of the Reactively Sputtered Al2O3-Si Structure
Authors: Tanaka Toshio , Iwauchi Shigeki
Published: November 2005

The interface characteristics of Al2O3-Si structures formed on silicon wafers by dcreactive-sputtering of aluminum in an oxygen ambient are evaluated. The presence of a dispersion of interface state time constants was found by measuring the parallel conductance of the MOS structures. An attempt is made to analyze the experimental results by using the tunneling model. We conclude that traps are distributed in the Al2O3 to a depth of 4.8Å from the interface with densities of the order of 1011/eV·cm2 or less. These densities were further reduced by hydrogen treatment. The electron capture cross section of the traps located at the interface is about 1.5×10-14 cm2 and that for holes is smaller by about a factor of 10.
Transport Properties of Metal-Silicon Schottky Barriers
Authors: Arizumi Tetsuya , Hirose Masataka
Published: November 2005

Schottky barrier diodes were fabricated by vacuum depositions of Au, Ag, and Cu onto chemically cleaned silicon surfaces and their current-voltage and capacitance-voltage characteristics were investigated in details over a temperature range between 100°K and 350°K. The current-voltage characteristics obtained are of nearly ideal Schottky barrier type and the current transport in the barriers is dominated by the thermionic emission and the image force effect. The temperature coefficient of the barrier height, the forward “n”, and the image force dielectric constant were found to be (2.67±0.60)×10-4 eV/°K, 1.01∼1.02, and 11.5ε
0 respectively. The departure from the ideal characteristics was explained by the generation-recombination current in the barrier region.
Application of Holographic Interferometry to the Measurement of Poisson's Ratio
Authors: Yamaguchi Ichirou , Saito Hiroyoshi
Published: November 2005

Holographic interferometry is applied to obtain the contour lines of deformation of a plate by pure bending. According to the theory of elasticity they are hyperbolas and from the angle between their asymptotes Poisson's ratio of the plate material is determined. By the real time method an accuracy of 1% is attained in the case of steel plates. The dependence of the value on the plate shape is also examined.
Effects of Auxiliary DC Discharges on the Performance of a Linear MHD Generator Using Potassium-Seeded Argon Plasmas
Authors: Shirakata Hirofumi , Hiramoto Tatsumi , Yano Syukuro
Published: November 2005

Experimental results are described concerning the effect of preionization by DC discharge parallel to the magnetic field on the performance of the linear MHD generator. Experiments were made with a blow-down facility, using a potassium-seeded argon or a K2CO3-seeded argon in the temperature range of 1600°–1950°K at 1 atm and Mach number below 0.27.
When the discharge was stable and uniform, the short-circuited current increased with increase in the applied discharge current, and the decrease in the nonuniformity of the electron density in the normal direction was indicated. However, the effective Hall parameter was not increased by the discharge. The enhancement in the electron density in the central flow region due to the discharge was concluded. However, the existence of the magnetically induced nonequilibrium state could not be verified. A discussion is made on the estimation of the recombination coefficient.
The Existence of the Field Minimum Line with Arbitrary Curvature and Torsion
Authors: Sometani Taro , Yamamoto Kenzo
Published: November 2005

In the light of plasma containment by means of a magnetic well containing closed flux surfaces, the existence of the vacuum field minimum line with arbitrary curvature and torsion is shown. An orthogonal curvilinear coordinate system related to a non-planar curve is used for calculating field components. It is shown that the existence of such field minimum is possible at least with a class of vacuum fields.
Construction of a New Type X-ray Diffraction Camera for High Pressure Studies and Its Application to the Measurement of Compressibility of β-SiC
Authors: Saito Shinroku , Ozaki Yoshiharu
Published: November 2005

This report contains a new apparatus for x-ray diffraction study at very high pressure and the measurement of compressibility of β-SiC. The x-ray camera is based on a Debye-Scherrer type geometry and Mo K
α radiation is used. The point is that the x-ray tube and camera are oscillated synchronously around the pressurized sample. This is useful for obtaining clearer diffraction pattern and for doing single crystal analysis at very high pressure. Using the apparatus, the effect of pressure up to 170 kbars was measured on the lattice parameter of β-SiC. The determind compressibility K=4.8×10-7/bar of β-SiC showed no significant influence of pressure. From this result, Grunneisen's constant γ=0.78 was calculated.
On the Stability of Nonhomogeneous Shear Flows
Authors: Banerjee Mihir B.
Published: November 2005

The equilibrium of a parallel shear flow in an inviscid, non-heat-conducting, incompressible fluid of density ρ which varies as a function of the vertical coordinate z is examined in the present paper. The principal results established are as follows; (a) Neglecting the effect of heterogeneity of the fluid on the inertia in comparison to its effect on the potential energy, the non-existance of non-singular as well as singular neutral modes has been proved for any general velocity profile U(z) provided the local Richardson number J(z) is less than -1 every where in the flow domain (b) a necessary condition for the existance of stable modes is obtaind under most general conditions. (c) bounds for the phase velocity, c
γ, has been obtained for stable modes and (d) a sufficient condition of instability is established for a certain class of velocity and density distributions.
A Method of Determining Dead Time of an X-Ray Detecting System
Authors: Fukamachi Tomoe
Published: November 2005

An improved single-foil method to determine the effective dead time of a pulse-detecting circuit is described. Experimental comparison with other methods showed that a better accuracy was achieved. The present method is also useful for determining accurately the absorption factor of a sample and the attenuation factor of absorbers.
Growth of a Large Number of Iron Whiskers by the Reduction of Halides
Authors: Kittaka Shigeyoshi , Kaneko Tsutomu
Published: November 2005

A great number of iron whiskers have been grown by the reduction of iron halides with addition of a small amount of carbon black. The addition of carbon black to the halides was effective for growing a large number of iron whiskers in the atmosphere of hydrogen and a charcoal-air system. Some of the whiskers had a foreign particle at the tip, and their mechanical property and morphology were similar to that of the normal whisker. The whiskers of another type were fine and often grew outward from a carbon black particle in a bundle form. Most of the halide in the original charge was reduced to iron whiskers. Some properties of the whiskers and the growth mechanism were discussed. Experimental results indicate that a chemical reaction at a growth step is required and carbon black added provides the growth site as foreign particles.
Some Properties of Silicon Nitride Films Produced by Radio Frequency Glow Discharge Reaction of Silane and Nitrogen
Authors: Kuwano Yukinori
Published: November 2005

Silicon nitride films are deposited on silicon wafer at low temperature by radio frequency glow discharge reaction of silane and nitrogen. The main peak position of infrared transmission spectra, the growth rate and the etch rate of the nitride films change respectively from 870 to 820 cm-1, from 0.8 to 6.5Å/sec and from 150 to 5Å/sec in 15% HF etchant with changing silane concentration from 0.1 to 2.5 mol %. The etch rate is larger than that of the thermally grown silicon nitride. The dielectric constant of nitride films changes from 8 to 5 with changing substrate temperature from 500 to 25°C. The nitride film deposited at as high temperature as 500°C shows a large hysteresis of C–V curve. The silicon nitride film deposited at the substrate temperature of 300°C and at the silane concentration of 0.5 mol % is stable against B–T treatment as well as thermally grown silicon nitride films. The value of flat-band surface charge ranges from 7 to 14×10''/cm2, the value is relatively small in comparison with that of thermally grown nitride.
Thermoelecric Effect in Semiconducting Barium Titanate
Authors: Brahmecha B. G.
Published: November 2005

Thermoelectric measurements were carried out on polycrystalline semiconducting barium titanate systems. Doping elements used were erbium and terbium. The ambient temperature of the samples was varied from room temperature to 200°C. It was found that the thermoelectric power changes its sign beyond the transition temperature and becomes positive, even though the carrier concentration remains constant. A possible mechanism based on the idea of electron-phonon Umklapp process has been suggested to explain this reversal of sign.
Frequency Limit of LSA-Mode Oscillations Estimated from the Hot Electron Problems in the High Frequency Electric Field
Authors: Nakamura Michiharu
Published: November 2005

The frequency dependence of the drift velocity-field characteristics of n-type GaAs and the frequency limit of LSA-mode oscillations were investigated by solving the time dependent conservation equations of the electron number, momentum and energy for the lower and upper valleys. The velocity-field characteristics at high frequencies differed significantly from that for DC field and showed hysteresis loops. The maximum frequency of the LSA mode oscillation was estimated to be about 150 GHz.
Junction Temperatures under Breakdown Condition
Authors: Okuto Yuji
Published: November 2005

A method of determining the junction temperature under breakdown condition is described.
The junction temperature T
1 is calculated from the applied voltage and the current in the following equation:
V
1=V

B0·{1+β(T
1-T
0)}+I
1·ρ
s
c0·{1+γ(T
1-T
0)},

where V
1 and I
1 are the applied voltage and current, V

B0 and ρ
s
c0 are the breakdown voltage and the space charge resistance at the ambient temperature T
0, and β and γ are the temperature coefficients of V

B
and ρ
s
c
, respectively.
Based on this method, the burn-out temperatures of mesa-type Si p
+–n junction diodes are found to be between 200∼300°C.
The cause of burn-out at such a low temperature is also discussed.
Electrical Detection of Etching and Regrowth Processes in Sn Solution Regrowth Method
Authors: Nii Riro , Honda Takashi , Kawasaki Yasuhiro , Shimizu Nobuo
Published: November 2005

A technique to control both etching and regrowth processes in Sn solution regrowth method is proposed.
Two Sn melts were made into contact on both sides of a n-type GaAs wafer, and constant current was passed through them. The detected voltage between Sn melts was used for the control of the wafer thickness. From the analysis of the contact properties of molten Sn and GaAs, it was found that, in the etching process, the voltage was mainly equal to the sum of ohmic drop in GaAs bulk and the drop of Schottky barrier resistance at Sn-GaAs contact. In the regrowth process, the Schottky barrier diminished abruptly, owing to the n
++ layer deposited on GaAs. The electrical signals corresponding to these processes could be used for the control of n and n
++ layer thickness.
C-V Characteristics of MOS Diodes Prepared by SiH4-NO2System
Authors: Haneta Yuichi
Published: November 2005

Properties at the Si-SiO2interface associated with vapor deposited SiO2films at low temperature were studied experimentally using the MOS diodes. SiO2films were deposited on then-type silicon substrates by the reaction of SiH4with NO2at a temperature of 450°C. The effects of surface treatment of silicon substrate prior to deposition, substrate orientation, and electric stress in MOS diodes were examined, as well as the location of the surface states. The results indicate that the properties at the Si-SiO2interface of MOS diodes prepared by this method are different from those of MOS diodes obtained from thermally grown SiO2films, that is, no orientation dependence of the surface charge density was observed, and the surface treatments of substrate prior to deposition influenced remarkably on surface charge density. It was found that the surface treatments of silicon in an H2O2solution and annealing in hydrogen after vapor etching with HCl are effective to obtain a smaller surface charge density. The surface state density is calculated from the the theoretical and experimental C–V (capacitance-voltage) curves measured at high frequency and discussed.
Near Threshold Behavior of Stimulated Brillouin Scattering in an Off-Axis Resonator
Authors: Ito Toshio , Takuma Hiroshi
Published: November 2005

Strong interference of the first Stokes Raman radiation with the stimulated Brillouin radiation has been observed in an off-axis resonator: Brillouin gain decreases appreciably by the presence of the Raman radiation in a medium such as CS2, in which the Raman and Brillouin scatterings can be stimulated simultaneously. Such a type of interference can be explained as the Raman scattering of the Brillouin photons stimulated by the first Stokes Raman photons. A classical theory has shown a quantitative agreement with the experiment. The anti-Stokes Brillouin components have not been observed even though the laser excitation was intense enough to allow the observation of the multiple Stokes components which were excited directly in the off-axis resonator without the feed-back effect of the laser as an amplifier.
Mass Dependence of the Factor (R) in Hull's Equation. Part II.
Authors: Grais Khairi I.
Published: November 2005

An empirical formula is investigated for the mass dependence of the factor (R) in Hull's equation, that was known to calibrate photographic plates for ion detection as a method of quantitative analysis with a mass spectrometer. Hull's equation in its modulated form showed good agreement with the experimental date obtained.
Hologram Schlieren and Phase-Contrast Methods
Authors: Tsuruta Tadao , Itoh Yoshinobu
Published: November 2005

Holography was applied to the schlieren and phase-contrast methods and enabled the visualization of a minute phase change occurring in an object which scattered light. One makes a hologram first with the phase object in position and afterwards illuminates it by the object illuminating beam with the object out of the path. Then the phase change due to the object is made to add to the reconstructed reference wavefront and is rendered visible by spatial-filtering the point image formed by the wavefront. First experiment was carried out of a striation of liquid in a cell which was illuminated diffusely from behind. This principle is also applicable to the removal of aberrations of a conventional arrangement for transparent objects. The second experiment was performed of a hot soldering iron placed in a pipe of glass and a sensitivity competitive to that realized by using an aberration-free arrangement was obtained. An accuracy necessary to locate the hologram plate to its original position and the effect of the emulsion shrinkage were also discussed.
X-ray Diffraction Topographic Studies of Dislocations in Natural Large Ice Single Crystals
Authors: Fukuda Akeharu , Higashi Akira
Published: November 2005

The method of X-ray diffraction topography was adopted to reveal the dislocation structure in natural, large ice single crystals which has been hitherto used for the extensive experiments of plastic deformation. The topographs show clear images of curved and straight dislocation lines lying on the basal planes of the crystal. Dislocation density is in the order of 104 cm-2 and Burgers vectors are (a/3)<112̄0> or c[0001]. In many cases, edge dislocations compose the small angle tilt boundaries of which tilt angle is less than 1° of arc. Size of the subgrains bordered with such boundaries is in the order of 1 mm or more and it differs very much from the size of mosaic blocks evaluated from primary and secondary extinctions of X-rays. Another characteristic feature is that screw dislocations of one Burgers vector are much less than those of other two equivalent Burgers vectors of (a/3)<112̄0> system.
Low Temperature Internal Friction and Modulus Change in Plastically Deformed Iron Single Crystals
Authors: Kakegawa Makoto , Sakamoto Koshiro
Published: November 2005

An experimental study is made of internal friction and modulus change of iron single crystals containing small amounts of interstitial impurities. Measurements are made over a temperature range from 5°K to 150°K, and a broad thermally activated relaxation peak of internal friction is observed near 50°K at the frequency of 100 kHz for the specimens deformed in tension at room temperature. This relaxation peak of Fe single crystals resembles that of other b.c.c. metals such as Nb, Mo, Ta and W. It seems likely that the elementary process which contributes to the thermally activated process at low temperatures is a motion of geometrical kinks produced by the room temperature deformation.
Angular Dependence of the Apparent Work Function of Carbon-Adsorbed Tungsten Tip
Authors: Okuyama Fumio , Hibi Tadatosi
Published: November 2005

Unusually oriented carbon-adsorbed tungsten tips are made by a method developed by the present authors. Changes of the apparent work function and of the emission current on several crystal planes of these tips are measured in a F.E.M. tube as a function of angular distance from its apex. It is found that the work functions of the crystal planes become small in order of {110}, {100}, {221} and {210}, and also that the change in the apparent work function with the increase in angular distance becomes pronounced in this order. The crystal plane having smaller work function is found to show more pronounced decrease of emission current with the increase of angular distance from the apex compared with the crystal plane having larger work function.
Interface-wave Instability in a Parallel Arrangement of Two Semiconductor Sheets with Transverse Magnetic Field
Authors: Okamoto Hiroshi , Mizushima Yoshihiko
Published: November 2005

The property of carrier waves which propagate along a surface of a semiconductor sheet is analyzed in the case with transverse magnetic field. The results show that two eigen-modes of the TM-wave exist in the same manner as in the case without magnetic field. By applying the analysis to the interface of two sheets of semi-conductors arranged in parallel with each other, expression of instability of the coupled surface carrier wave (interface wave) is obtained, which includes also the effect of diffusion. Numerical estimation is made to find the condition of operation at high frequency.
Study of Multi-Wavelength Oscillations in an H2O Laser by Rate Equations
Authors: Takeuchi Nobuo , Kasuya Takahiro , Shimoda Koichi
Published: November 2005

The far-infrared laser oscillations in water vapor is described theoretically in the form of rate equations in which the molecular rotation-vibration interaction of either Fermi or Coriolis type is taken into account.
The theory is developed for the case of pulsed operation of relatively long duration on the assumption that the rotational relaxation time is much shorter than the duration of the excitation pulse. Theoretical expressions for (1) the output power in the steady state as a function of pumping rate and (2) the start-oscillation condition are given. The effects of multi-wavelength oscillations are also obtained and compared with experimental results.
Nuclear Magnetic Resonance of Polyamino Acids. I
Authors: Tsutsumi Akihiro
Published: November 2005

In order to study molecular motion in polyamino acids in solid state, nuclear magnetic resonance measurements were carried out over a wide range of temperature for following ten polymers; poly-γ-methyl-L-glutamate, poly-L-methionine, poly-γ-benzyl-L-glutamate, poly-δ,n-carbobenzoxy-L-ornithine, poly-ε,n-carbobenzoxy-L-lysine, poly-L-ornithine hydrochloride, poly-L-lysine hydrochloride, poly-sodium-L-aspartate, poly-sodium-D-glutamate and poly-L-tryptophane. Comparison of experimental and calculated second moments showed that all polymers except for poly-γ-methyl-L-glutamate and poly-L-metionine are in rigid state at 77°K. Decrease of the line width and the second moment with increasing temperature was mainly interpreted in terms of motion of side chain. The narrowing temperature was found to be considerably affected by the type of side chain. The polymers which have a benzyl ester group showed a very rapid narrowing at room temperature. It should be noted that more than two methylane groups are required in the side chain to cause such a narrowing. Poly-sodium-L-aspartate, poly-sodium-D-glutamate, poly-L-ornithine hydrochloride and poly-γ-methyl-L-glutamate showed a rapid narrowing at high temperatures. This narrowing was attributed to motion of main chain in randomly coiled state.
Electrical Conduction and Switching in Amorphous Semiconductors
Authors: Hamaguchi Chihiro , Sasaki Yoshiro , Nakai Junkichi
Published: November 2005

Electrical conductivity, thermally stimulated current, plaotoconductivity and switching effect have been investigated in amorphous semiconductors of As-Te, As-Te-Ga and As-Te-Ga-Ge-Si chalcogenides. The electrical conductivity σ is found to be expressed by σ=σ0exp (ΔE/kT) with conductivity activation energyΔEranging from 0.12 eV to 0.47 eV depending on the compositions in the temperature range of 300°K to 500°K. A memory effect appears in conductivityvs.temperature curves of such a specimen that shows memory effect in the switching experiments; high conductivity state atT=500°K remains unchanged down to room temperature. Thermal quenching gives the initial low conductivity at room temperature. From thermally stimulated current measurements, the energy levels of trapping centers are found to be about 0.18 eV and 0.23 eV. Switching experiments are made in thin and thick specimens at room temperature.
Desorption and Migration of Cesium Adsorbed on Tungsten in the Presense of an Electric Field
Authors: Nomura Setsuo , Sugata Eizi
Published: November 2005

Studies of the field desorption of cesium from tungsten and the equilibrium concentrations of cesium under electric fields are made by a field emission microscope (FEM). It is observed that, at small concentrations, the desorption begins from (211) vicinities and proceeds along cross-bone zones, while, at large concentrations, the desorption occurs instantaneously from the whole surface of the tip apex. The threshold field strength for desorption increases with the increase of the surface concentration of cesium. Surface migration of Cs atoms towards the tip apex from the tip shank following the field desorption is suppressed by an applied negative electric field, and the equilibrium concentration between the apex and the shank appears. These equilibrium concentrations under various electric fields are determined, and the results are used to calculate the dipole moments of the ad-atoms for many concentrations.
Infrared and Red Photoluminescence in Gap: Zn, O
Authors: Maeda Keiji , Naito Makoto
Published: November 2005

Intensity ratio of infrared to red photoluminescence in GaP crystals doped with various amounts of Zn and O is measured at room temperature. The ratio is constant for low Zn concentrations but decreases for higher Zn concentrations. The results are explained qualitatively by a simple model of excitonic recombination at Zn-O complex and infrared pair recombination.
Investigation of Energy Dissipation of Electrons in Al- and Cu-Targets by Monte Carlo Method
Authors: Shimizu Ryuichi , Honji Masahiro , Murata Kenji
Published: November 2005

A couple of formulae for mean ionization potentialJin Bethe's expression for stopping power was exemplified as for it's adaptability to calculate the energy loss distribution of electrons and the depth distribution of X-ray production by Monte Carlo Method, which will be significant in the field of scanning electron microscope (SEM) and electron probe microanalyser (EPMA). The contributions of mean ionization potential to the final phenomena such as energy dissipation, backscattering ratio and X-ray production etc. were investigated by simulating them by Monte Carlo calculation and the results were compared with the experiments on the normalized energy loss distribution in silicon oxide reported recently by Hoff and Everhart and on the depth distribution of characteristic X-rays.
Charge Exchange of Carbon and Nitrogen Ions in Nitrogen Gas
Authors: Tonuma Tadao , Miyazawa Yoshitoshi , Karasawa Takashi , Kohno Isao
Published: November 2005

Electron loss and capture cross section of carbon and nitrogen ions were measured at 3.5∼7 MeV/nucl., i.e. velocities of 2.6∼3.7×109 cm/sec in nitrogen gas. Cross sections obtained were σ45, σ56, σ65, for carbon ions and ∑\limits
k=5
7σ4k for nitrogen ions when they passed through the charge exchange (collision) chamber. Cross sections of single electron loss σ45 and σ56 are nearly proportional to v
0/v and those of single electron capture σ65 are proportional to (v
0/v)6, where v
0 is the atomic unit of velocity and v is ion velocity.
This paper reports also on the comparison between the beam attenuation of N4+ ions, which were accelerated in the IPCR 160 cm cyclotron, caused by charge exchange at collisions with residual gases, and the attenuation calculated from measured ∑\limits
k=5
7σ4k in nitrogen gas.