bluuebunny/crossref_metadata_2025 huggingface dataset:
Superconductivity in Ba1-xSrxPb0.75Bi0.25O3
Authors: Suzuki Minoru , Murakami Toshiaki , Inamura Takahiro
Published: November 2005

In order to investigate the relation between superconductivity and the lattice constant, a perovskite-type Ba1-x
Sr
x
Pb0.75Bi0.25O3 oxide system was synthesized, in which the lattice constant decreased with increasing Sr content. The system was found to be superconducting with x<0.3 and semiconducting with x>0.3. Reduction of the distance between Pb ions was expected to enhance superconductivity, but this was not the case ; the critical temperature T
c was no higher than that of BaPb0.75Bi0.25O3.
Effect of the Angular Velocity on the Sedimentation Constant of Rod-like Macromolecules in the Ultracentrifuge
Authors: Saitô Nobuhiko , Hasegawa Michio
Published: November 2005

The sedimentation constants of tobacco mosaic virus and desoxyribonucleic acid increase with the increase in the angular velocity of the ultracentrifuge, especially in concentrated solutions. This effect is theoretically treated for very dilute solutions taking account of the orientation effect of rod-like molecules under a strong centrifugal force. The effect is not very great in dilute solutions. Calculations are carried out for rod-like pearl necklace models and ellipsoidal particles.
Etch Patterns and the Mechanism of Etching of Germanium by Iodine Vapor
Authors: Arizumi Tetsuya , Akasaki Isamu
Published: November 2005

In the reaction between iodine vapor and Ge, the latter is etched away mainly as GeI2 at temperature between 450° and 550°C. The rate of this reaction is not determined by the supply of positive holes. The relative reactivities of three crystallographic surfaces are in the order: {110}>{111}≥{100}, which is the same order as the densities of surface atoms. Thus {100} and {111} planes of slower etching rate are always revealed and pyramidal pits of two-, three- and four-fold symmetries are developed on the surfaces {110}, {111} and {100}, respectively. A triangular pit formed on the (111) surface is regarded as a positive pit and it does not always correspond to a dislocation.
Vapor Growth of GaAs in the Polar Direction
Authors: Okada Takasi
Published: November 2005

Crystals of GaAs and of Ge are grown on the {111} surfaces of GaAs and of Ge single crystals by the vapor phase reactions using iodine as the carrier gas. GaAs is grown epitaxially on the Ga (111) surface and not on the As (1̄1̄1̄) surface. These phenomena seem to be contrary to the fact that more perfect crystals of GaAs tend to grow from the melts on the As (1̄1̄1̄) surfaces than on the Ga (111) surfaces. It is also observed that (i) Ge is grown epitaxially both on the Ga (111) and on the As (1̄1̄1̄) surfaces, (ii) GaAs is grown epitaxially on the Ge (111) surface, its growth direction being mainly in the <111> axis of GaAs and (iii) growth of GaAs in the <1̄1̄1̄> direction takes place locally on the Ge (111) surface, its area decreasing gradually in the course of growth. A possible explanation is proposed.
Electron Microscope Study of the Crystal Structure of the Martensite in a Copper-Aluminium Alloy
Authors: Nishiyama Zenji , Kajiwara Setsuo
Published: November 2005

The crystal structure of β' martensite in a Cu–11.7% alloy has been studied by transmission electron microscopy and electron diffraction. The structure has a monoclinic lattice, whose unit consists of 6 close-packed layers having a superlattice. It can also be described as an orthorhombic lattice having lattice constants of a=4.49 Å, b=5.19 Å, c=38.2 Å, (a: b: c=√3: 2: 18√\tfrac23), and consisting of 18 layers A
B'C
B'C
A'C
A'B
A'B
C'B
C'A
C'A
B', where the positions of atoms in each layer (a
b plane) are

(A)  Al:(00);    Cu:(0\tfrac12), (\tfrac12\tfrac14), (\tfrac12\tfrac34),    (A')=(A)+(\overrightarrow0\tfrac12),
(B)=(A)+(\overrightarrow\tfrac130),       (B')=(B)+(\overrightarrow0\tfrac12),
(C)=(A)+(\overrightarrow\tfrac230),       (C')=(C)+(\overrightarrow0\tfrac12),

where (A)+(\overrightarrow\tfrac130) means that all the atoms in layer `A' are displaced by the amount of vector (\overrightarrow\tfrac130).
A Note on the Shape of Cathode Tip in the Field Emission Microscope
Authors: Hibi Tadatosi , Ishikawa Kazuo
Published: November 2005

Successive changes in the shape of field emission nickel cathode tips resulting from two types of treatment–simple heat-treatment and heat-treatment with continuous application of 5000 V–were observed. As the results, it was found that in the former case the rate of decrease in length is more pronounced than that in thickness, while in the latter case the tip becomes thinner nearly uniformly over the entire surface until the tip becomes of certain thickness. Also it has been clarified that heat-treatment with continuously applied anode voltage is necessary to obtain a good tip.
Photo-Micrographic Observations on X-Irradiated Rochelle Salt Crystals
Authors: Okada Kenkichi
Published: November 2005

Observations on cavities in damaged rochelle salt and etch patterns on the surfaces are made photo-micrographically. It is found that thin cavities are formed by thermal annealing after irradiation. Etch pits on c– and b–faces change from pyramidal to hip-roof-shaped while cavities are formed. Three type of cavities lie on three basic planes, each of which are arranged in layer structure. Hip-roof-shaped pits correspond to emergence lines of cavity planes on a crystal surface. Certain distributions of the cavities which presumably decorate dislocations were obtained.
Measurement of Anisotropy Dispersion by means of Ferromagnetic Resonance
Authors: Uchiyama S. , Masuda M. , Sakaki Y.
Published: November 2005

It is reported that the magnitude dispersion and the angular dispersion of the anisotropy energy in permalloy films can be measured by means of the ferromagnetic absorption measurement at a radio frequency of about 0.5 Mc/s. Principles of the method for dispersion measurement are developed here on the basis of a particle domain model. The experimental setup as well as the results obtained are also shown.
Surface Structure of Dried Skim-milk Powder Particle by Electron Microscopic Observation
Authors: Taneya Shin'ichi
Published: November 2005

Dried skim-milk has the following peculiar fluid property: when the powder adsorbs about 7% water, its fluidity increases contrary to the behaviour of the ordinary kind of powder. For elucidation of this abnormality, the powder particle is examined under electron microscope. At 7% water content, the development of crystals is observed on the surface, each crystal growing to about 2µ in size. By means of X-ray diffraction as well as of infrared absorption, these crystals are identified as α-lactose hydrate.
Theoretical Analysis of Nuclear Resonance Magnetic Field Control System
Authors: Sasaki Yutaro
Published: November 2005

A precise magnetic-field stabilizer using nuclear resonance techniques is proposed and control characteristics of the stabilizer are analyzed in order to obtain conditions for optimizing control. In this control system, the error signal, which is the output voltage of the nuclear resonance magnetic-field detector, is doubly fed back through an anti-hunt circuit (wide-band DC power amplifier) as usual and further through a drift compensating circuit (integrator using a servomotor). According to the analysis, the control system has a short settling time and zero static error to a unit step disturbance. Moreover, the anti-hunt circuit contributes to making the whole system stable as well as to suppressing the field fluctuations, and the drift compensating circuit plays a role of compensating drifts of the static field. Thus the proposed stabilizer is effective for the precise stabilization of magnetic fields over a long duration.
Nature of Radiation Defects in Silicon Single Crystals
Authors: Saito Haruo , Hirata Mitsuji
Published: November 2005

Floating zone Silicon single crystals containing phosphorus were irradiated with Co 60 γ-rays or electrons of 2 Mev at room temperature. Temperature dependence of Hall coefficient after irradiation showed the presence of two net acceptor levels, 0.17 ev and 0.38 ev below the conduction band. The introduction rate of the deep level increased with increasing phosphorus concentration, while that of the shallow level slightly decreased with increasing phosphorus concentration. The activation energy for the annealing of the 0.38 ev level was found to be 0.94 ev in the temperature range, 120–180°C. All of the results obtained can be successfully explained, if Watkins' model was adopted.
Effects of Heat Treatment on Lead Telluride under Tellurium Pressure:–Carrier Concentration Dependence of Mobility and Etch Pits on Worked Surfaces–
Authors: Sato Yasuo , Fujimoto Masatomo , Kobayashi Akio
Published: November 2005

Single crystals of lead telluride having carrier concentrations from 8×1016to 6×1017/c.c. forn-type and from 1017to 6×1018/c.c. forp-type have been obtained with controlling tellurium pressure. Hall mobility of carriers depends on carrier concentration and has a maximum as a function of carrier concentration. Etch pits on crystal surfaces have been observed. Their density is 7×106/cm2before annealing and decreases to 4×106/cm2after annealing.
Measurement of Collision Broadening of Resonance Lines of Calcium Ion by a Low-Resolution Spectrometer
Authors: Urano Yoshio , Monju Mikio , Harima Hiroshi , Tachibana Kunihide
Published: November 2005

The line widths of calcium ion resonance lines broadened by argon gas are measured. Radiation from the equilibrium region behind the reflected wave in a shock-tube is studied using a rapid scanning spectrometer. A method of measuring the small broadening half-width using a relatively low-resolution spectrometer is devised. The measured broadening coefficients of 2.60(±0.81)×10-20 cm-2 for the H-line and 2.84(±0.85)×10-20 cm-2 for the K-line agree fairly well with previous results.
Compensation Effect in the Electrical Conduction Process in Some Nitroaromatic Semiconductors
Authors: Ghosh Alpana , Jain Kapur Mal , Mallik Biswanath , Misra T. N.
Published: November 2005

The validity of the compensation rule has been studied for some nitroaromatic semiconductors, namely 1,3,5-trinitrobenzene (TNB), 1,4-dinitronaphthalene (DNN) and 9-nitroanthracene (NA). The activation energy (E) of electrical conductivity of these semiconductors was varied by adsorbing different organic vapours and also different amounts of a particular vapour. Only vapours showing fast and reversible adsorption and desorption were used for the purpose. Such vapours, on adsorption on the semiconductor crystallites, enhances the conductivity of these nitroaromatics with concomitant increase in E. It has been observed that specific conductivity in these nitroaromatics follow the compensation equation

log
σ(T)=log
σ0
′+[1/T
0-1/T]E/2K.

The constants E, σ0
′ and the compensation temperature T
0 characterise the semiconductor system, σ0
′ and T
0 being specific to a particular nitroaromatic compound. Various methods used for evaluating σ0
′ and T
0 have yielded consistent values suggesting a physical basis for the compensation effect. T
0 has been found to play a significant role in dark conduction process.
Photoluminescence Measurements for Cd-Diffused InP p-n Junction
Authors: Ohtsuka Ken-ichi , Yamazoe Yoshimitsu , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

An attempt to investigate the diffusion profile of Cd into InP has been carried out by photoluminescence measurements. The PL-intensity profile of a Cd-related D-A pair emission line was measured by scanning the excitation laser beam spot over an angle-lapped Cd-diffused InP surface. The profile agrees well with the previously-reported abrupt Cd-diffusion profile, and the depths are very close to those measured by EBIC. These results suggest that the essential features of the concentration profile of the Cd-acceptor in InP can easily be measured by photoluminescence.
A Picosecond Optical Gate Using Photo-Induced Grating
Authors: Morimoto Akihiro , Kobayashi Tetsuro , Sueta Tadasi
Published: November 2005

A picosecond optical gate using a photo-induced grating created in a nonlinear medium by the interference of two intense picosecond optical pulses is proposed. Diffraction by the photoinduced grating was tested with CS2 (carbon disulfide) Kerr liquid and a mode-locked Nd: glass laser. The experimental results showed that the diffraction can be used as a picosecond optical gate.
Pinning Force of a Nonideal Superconductor Containing Pins with Large Interaction Forces. I. High Pin Density
Authors: Matsushita Teruo
Published: November 2005

The global pinning force density is calculated for a superconductor containing dense and strong pins using a statistical method. The resultant pinning force density is proportional to an elementary pinning strength and obeys a linear summation. The obtained scaling law of the pinning force density coincides approximately with experimental results on irradiated Nb specimens. Quantitative agreements with experiments also seem to be satisfactory.
TEM Observation of Dark Defects Appearing in InGaAsP/InP Double-Heterostructure Light Emitting Diodes Aged at High Temperature
Authors: Ueda Osamu , Komiya Satoshi , Yamakoshi Shigenobu , Kotani Tsuyoshi
Published: November 2005

Dark defects which appear during high temperature aging of InGaAsP/InP 1.27 µm double-heterostructure light emitting diodes, were investigated by transmission electron microscopy and energy dispersive X-ray spectroscopy. Dark-spot defects are often observed in the electro-luminescent patterns of aged diodes, while cross-shaped <100> dark-line defects are rarely observed. The dark-spot defects, which correspond to bar-shaped precipitates, are thought to be generated by the precipitation of the host atoms during operation at certain nucleation centers. The cross-shaped dark-line defects, which are associated with complicated defects consisting of small dislocation clouds and fibrous edge-like dislocations, are thought to be generated by local melting at In and/or P rich inclusions.
Causes of Thickness Non-Uniformity in Silicon Ribbon Crystals
Authors: Kuroda Ekyo , Matsuda Masatoshi , Maki Michiyoshi
Published: November 2005

Three kinds of thickness non-uniformity in silicon ribbon crystals grown using graphite dies were observed, and the cause of each type of non-uniformity pinpointed. One of these, uneven accumulation of molten silicon around the die top, was found to result in a large non-uniform temperature distribution near the growth interface, producing a non-uniform heat release pattern in the crystals. This in turn caused the meniscus to become unstable in shape and split. Uniformly thick ribbons 90 mm wide can be grown by preventing this accumulation, and this technique is expected to help to reduce the production costs of solar energy devices.
Temperature Dependence of the Band-Edge Effective Mass in n-InAs Deduced from Magnetophonon Resonance
Authors: Takayama Junji , Shimomae Koichi , Hamaguchi Chihiro
Published: November 2005

Magnetophonon measurements have been carried out in bulk n-InAs using magnetic field modulation technique to obtain the temperature dependence of the band edge effective mass. Resonance extrema forN=2, 3 and 4 were observed in the transverse magnetoresistance in the temperature range from 150 to 250 K and the effective masses were deduced taking into account the conduction band non-parabolicity and the polaron effect. The masses are 0.0231±0.005mat 150 K and 0.0219±0.005mat 250 K. The observed temperature dependence of the mass is discussed using Kane's formula for the nonparabolic conduction band and the momentum matrix element is determined to beP2=19–21 in units of eV.
Spectroscopy of Laser Scattered Light by Eye Lens
Authors: Sato Hideaki , Suzuki Norihito , Nakatani Hajime
Published: November 2005

The Spectrum of laser light scattered by proteins in an incubated whole lens is measured using a photon correlation spectrometer. From the measurements, it is found that the spectral line has two Lorentzian components, one being a wide spectral linewidth and the other a narrow one; and in cataractous lenses, the wide component cannot be observed. The narrow component shows the existence of aggregated proteins, and the diffusion constant corresponding to the wide component becomes smaller as the cataract progresses. The intensity ratio of the two scattered light components is sensitive to the degree to which the cataract has progressed in cataractous lenses.
Critical Condition of Twist-Domain Generation and the Effect of Pretilt Angles on Such Generation in Twisted Nematic Liquid Crystal Cells
Authors: Nakano Fumio , Isogai Masato , Itoh Ren , Satoh Mikio , Kandoh Yasuhiko
Published: November 2005

The critical conditions governing twist domain generation in twisted nematic cells was investigated theoretically with respect to chiral additives and pretilt angles. It was found that a critical margin twist angle (δc) was greatly affected by even a small change in the size of a pretilt angle. The theoretical analysis was supported by the results of experiments that were carried out with various combinations of cell materials, for example, rubbed organic films and organic sealants. This investigation proved that pretilt angle measurement is a useful means of selecting the combination of materials that will result in completely domain-free twisted nematic cells.
Transport of Photoexcited Carriers in Evaporated GexSe1-x Glass Films
Authors: Kim Gi Il , Shirafuji Junji , Inuishi Yoshio
Published: November 2005

Measurement of the time-of-flight of optically injected carriers was carried out in evaporated Ge
x
Se1-x
(0.2\leqslantx\leqslant0.4) glass films. The charge signal induced by drifting electrons showed the existence of two components corresponding to fast and slow electrons. The fast component was due to the nondispersive drift of electrons with high mobility which has been observed similarly in thick bulk samples while the slow component showed a dispersive transport character. The effective drift mobility was estimated from the kink point of the log-log plot of the current versus time. The magnitude of the fast component of the induced charge signal tended to saturate at high electric fields. On the basis of a simple model, the mobility and the carrier lifetime were separately estimated. Holes showed only the dispersive transport and the value of the effective hole mobility was close to that of the slow electrons.
Dependence of the Growth Rate of Interstitial Loops on Irradiated Crystallographic Directions in Electron Irradiated Pure Aluminum
Authors: Tanaka Kunihiro , Shimomura Yoshiharu
Published: November 2005

Pure aluminum was irradiated at 120°C with 200 keV electrons in an electron microscope to examine the dependence of the growth rate of interstitial loop (I-loop) on the direction of incident electrons. I-loops grew proportionally with the irradiation time at 120°C. When the specimens were irradiated so that the I-loops were visible by diffraction contrasts, the growth rate depended on both directions of the incident electrons and the diffraction conditions, while it did not depend on the diffraction condition when all the I-loops were invisible. The dependence of the growth rate of I-loops on the diffraction condition may be due to the change of effective electron flux along the atomic rows by dynamic diffraction. The displacement cross section is determined by the growth rate of I-loops when all I-loops are invisible. The threshold energy profile of the fundamental triangle in pure aluminum was obtained with a combination of the steepest descent and the conjugate gradient technique.
Liquid Phase Epitaxial Growth of CuGaSe2 on ZnSe
Authors: Asai Hiromitsu , Sugiyama Koichi
Published: November 2005

Liquid phase epitaxy of CuGaSe2 layers on ZnSe (111)A substrates with Bi and Pb solvents is described. Structural and compositional properties of the epilayers were investigated by means of X-ray diffraction, electron probe microanalysis and photoluminescence. The epilayers are composed of two layers of CuGaSe2-ZnSe solid solutions. The upper layers have the chalcopyrite structure whose lattice parameters are nearly the same as those of stoichiometric CuGaSe2, but the lower layers are considered to have the zincblende structure. Photoluminescence spectra with emission peaks at 750 and 800 nm were observed at 77 K for the upper and the lower layers, respectively.
Field-Ion Microscope Studies of Ni4W Type Ordering in the Near-Surface of Ni-16.6 at%W Alloy
Authors: Kingetsu Toshiki , Yamamoto Masahiko , Nenno Soji , Fukura Hidenori
Published: November 2005

Field-ion microscope observations were made on Ni-16.6 at.%W alloy quenched from the high temperature α phase region to investigate Ni4W type ordering in the near-surface during in-situ annealing. Somewhat below the peritectoid temperature, disc-shaped Ni4W domains of the particular variants were formed preferentially at some of {420}FCC planes on the surface regions with their disc faces being {110}BCT superlattice planes (at 950°C for ca. 5 min). The relaxation time of occurrence of an ordered domain at one of the {420}FCC nucleation sites and the rate of its thickness-increase were evaluated to be 520±260 s and 0.10±0.08 Å/s, respectively. Surface layers of a few to fifteen angstrom in thickness with lower degree of order were formed upon annealing for a few minutes at 920–860°C. The degree of order in the near-surface also decreased upon annealing partially ordered tips at the same temperatures.
Thermally Stimulated Current Properties of Mobile Ion in SiO2 Film of MOS Structure and Its Numerical Analysis
Authors: Yamashita Ken , Iwamoto Mitsumasa , Hino Taro
Published: November 2005

The behavior of sodium ions in the SiO2 layer of MOS structures was analyzed using a new numerical method. The method is based on ionic hopping, and drift in the space charge field and diffusion were also taken into account. The computed results were applied to interpret the properties of a thermally stimulated current obtained experimentally. This is a useful method for measuring transient ionic motion in insulating films. It was found that the observed characteristics could be understood by ionic hopping, without assuming a surface ionic trap which has been proposed as a model for the behavior of ions in the SiO2 film of MOS structures.
Pressure and Temperature Dependence of Dielectric Properties of Trissarcosine Calcium Chloride
Authors: Fujimoto Sanji , Yasuda Naohiko , Takagi Keisuke
Published: November 2005

The pressure (0–6 kbar), temperature (-200∼-70°C) and dc bias field (0–9×105V/m) dependence of the dielectric properties (permittivity, spontaneous polarization, coercive field and phase transition temperatures) of trissarcosine calcium chloride (TSCC) were measured. The effect of pressure on the dielectric properties was remarkable. A remarkable decrease in the permittivity occurred at a pressure of about 5 kbar, where the ferroelectric state terminates. The new phase III appeared when pressure was applied and became more stable with increasing pressure. Judging from the dc bias field and temperature dependence of the permittivity and the non-occurrence of hysteresis loops and other considerations, the pressure-induced phase III is believed to be antiferroelectric. The dielectric properties associated with the paraelectric-ferroelectric transition in TSCC are also successfully interpreted in terms of a phenomenological theory.
New Restricted Contact LEDs Using a Schottky Barrier
Authors: Chin A. K. , Zipfel C. L. , Dutt B. V. , Giuseppe M. A. Di , Bauers K. B. , Roccasecca D. D.
Published: November 2005

High radiance LEDs for optical communications require a small light emitting region to efficiently couple the emitted light into the optical fiber. The small light emitting region is generally accomplished by restricting the electrical contact on one surface of the device and isolating the remaining portions of the semiconductor surface from the conducting heatsink using a dielectric layer. In this paper, planar restricted contact LEDs, in which electrical isolation is achieved with a metal layer that forms a high resistance or non-ohmic contact (Schottky barrier) to the semiconductor, are demonstrated in the GaAlAs and InGaAsP/InP materials systems. These LEDs show comparable I-V characteristics and current restriction as devices fabricated with dielectric isolation. This new method of electrical isolation simplifies the fabrication procedure by eliminating the need for dielectric deposition and photolithography. Experiments to determine the long term reliability of these devices is in progress.
Time Behaviours of Visible Lines in Turbulently Heated TRIAM-1 Plasma
Authors: Hiraki Naoji , Nakamura Kazuo , Nakamura Yukio , Itoh Satoshi
Published: November 2005

Spectroscopic studies were carried out on turbulently heated TRIAM-1 tokamak plasma.
The temporal evolutions of the line radiance of visible lines were measured and two types of time behaviours of the line radiance were identified. The observed remarkable reduction of the line radiance of visible lines which have low ionization potential and are localized in the skin-layer due to the application of a pulsed electric-field for turbulent heating is attributed to the strong plasma heating in the peripherical region.
Spatial profiles of neutrals and ions which are related to these lines are calculated, and the temporal variations of these profiles caused by the application of the heating pulse are discussed.
Estimation of Escape Probability of Photons from Proportional Counters Filled at Different Low Pressures
Authors: Ansari M. Afzal
Published: November 2005

A special type of proportional counter has been constructed in which the source can be placed internally with provision for its covering and uncovering by an absorber, without disturbing the pressure inside the counter. Using this counter, the variation of the escape probability f
K of argon KX-rays with pressure was estimated. The intensity ratio I(KX-rays)/I(14.4 keV γ-rays) for a Co57 source at five different pressures was also determined and compared with the theoretical value. The Constancy of this ratio at these pressures supports the reliability of experiment.
Magnetic Instabilities in High Field Superconductors
Authors: Akachi Tatsuo , Ogasawara Takeshi , Yasukōchi Kō
Published: November 2005

In the process of magnetizing cylindrical specimens of a typical high field superconductor Nb-50 at.%Ti, flux jumps were induced by magnetic disturbances. The stability limit field H
fj increased steadily with increasing temperature, and no magnetic instability occurred for temperatures in excess of about 6.5 K. The calculation of H
fj was performed taking into account the cylindrical sample geometry and the critical state equation J
c
B
1-γ=α. According to the relative magnitudes of the magnetic diffusivity D
m and the thermal diffusivity D
t, the expression of H
fj was derived for two cases; (1) D
m>D
t, and (2) D
m ≪D
t. Good agreement between experiment and theory was obtained on the stability limit field H
fj and the temperature above which magnetic instabilities do not take place.
Josephson Effect in Magnetic Superconductors. I. Formulation
Authors: Yamashita Kazuhiko
Published: November 2005

The equations which describe the magnetic field, the persistent current and the energy in two magnetic superconductors joined together by an infinite junction were derived in the temperature region between the superconducting- and magnetic-phase-transition temperatures by means of the boson theory. The magnetic field distribution in the system was numerically estimated for a simple case. The magnetic field induced by the persistent current crossing the junction and the persistent current along the junction, and the spin magnetization magnetized by this field were calculated. The total magnetic flux in the range of one period along the junction which is the sum of spin magnetization and persistent current contribution is quantized. As a result, the current inversion was found to occur in the portion away from the junction.
Time-Resolved Reabsorption Effect on the Fluorescence Decay of Anthracene Crystal and Solution
Authors: Shimura Hiroshi , Ohba Yujiro
Published: November 2005

The wavelength dependence of the fluorescence decay time for an anthracene crystal, is discussed with reference to a time dependent reabsorption model, and the time dependence of the reabsorption is shown to be related to the distribution of excitons. From the time-resolved analysis of the temperature dependence of the fluorescence decay, the reabsorption effect is shown to increase over the whole decay period. In order to analyze the concentration dependence of the fluorescence decay in a solution, the Stern-Volmer type equation is applied to the experimental data with two new parameters being introduced. Optimum values of the parameters are obtained from the calculated curves which agree fairly well with the experimental data. The reabsorption effect in the solution increases during a certain time period, but afterwards it decreases.
Absolute Density Measurement of Metal Atoms by Laser Resonance Scattering with the Aid of Rayleigh Scattering
Authors: Hamamoto Makoto , Maeda Mitsuo , Muraoka Katsunori , Akazaki Masanori
Published: November 2005

The absolute density of metal atoms such as iron and aluminium atoms, the knowledge of which is urgently needed for study of the high temperature plasma-wall interaction, was measured by the laser resonance scattering method within an accuracy of 50%. The calibration of the optical system was performed by using the Rayleigh scattering from argon gas at subatmospheric pressure, and the accuracy of the metal density measurement was confirmed by using accurately adjustable metal vapour from a Knudsen cell as a scattering target.
Heating and Particle Diffusion due to Lower-Hybrid Resonant Parametric Instability
Authors: Fujiyama Hiroshi , Watanabe Yukio , Akazaki Masanori
Published: November 2005

Heating and particle diffusion due to lower-hybrid parametric instability (resonant decay into lower-hybrid waves and backward ion-cyclotron waves) were investigated experimentally. From the measurement of the phase difference between density- and potential-fluctuation of backward ion-cyclotron waves, it was found that the former leads the latter as the parametric instability grows. This mechanism can be qualitatively explained by a simple fluid theory. The increase of this phase difference is followed by the anomalous increase of plasma particle flux across a magnetic field over the Simon diffusion.
Conducting Liquid Conveyer of Plasma Rings
Authors: Tomita Yukihiro , Mohri Akihiro
Published: November 2005

Current-carrying plasma rings can be conveyed in a cylindrical channel with a conducting liquid flow to which the outer poloidal fields of the rings freeze. Fast tilting motion of the ring is stabilized when the liquid surface is set close to the ring within a critical distance. The effects of a resistive tube duct installed for the liquid are also examined.
An Analysis of the Transient Responses of Acoustic Delay Lines
Authors: Okano Tatsuo , Tominaga Goroh
Published: November 2005

Transient responses of acoustic delay lines (ADLs) were simulated on the assumptions that gas molecules in each segment of an ADL were in thermal equilibrium and that the straight-through component in the intruding gas was negligibly small. The flow rate of gas through an orifice was evaluated by using expressions of orifice conductance applicable in a wide pressure range. In order to examine the adequateness of the present method, the results of simulations were compared with several experimental data. The influence of the location of vacuum pumps and of arranging a high speed shutter at the entrance of an ADL were also simulated.
Fabrication of SiO2 Grating Patterns with Vertical Sidewalls by SOR X-Ray Lithography and Reactive Ion-Beam Etching
Authors: Matsui Shinji , Moriwaki Kazuyuki , Masuda Noboru , Nakamura Takehiro , Aritome Hiroaki , Namba Susumu
Published: November 2005

SOR X-ray lithography is an effective means of obtaining surface relief structures with submicron line width, vertical sidewalls and large aspect ratios in resist, because it has advantages of high contrast and small beam divergence. Moreover, reactive ion-beam etching realizes a high fidelity pattern transfer from patterns delineated in resist into underlaying substrates. In this paper, it is shown that SiO2 grating patterns with sharp vertical sidewalls can be fabricated by CHF3 reactive ion-beam using masks of PMMA grating patterns replicated by SOR X-ray lithography. This result demonstrates that the combination of SOR X-ray lithography and reactive ion-beam etching is an excellent microfabrication technique.
Preparation of Monodomain Cells of Ferroelectric Liquid Crystals and Their Evaluation with an Optical Microscope
Authors: Kondo Katsumi , Kobayashi Fumiaki , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

We have observed the growing process of high quality homogeneous cells directly in a high magnetic field by using a microscope with an elongated tube of 846 mm in length. For improving the cell quality, the application of the magnetic field is the most effective in comparison with other methods, such as the application of an electric field, SiO oblique evaporation, rubbing, etc. Factors affecting the cell quality were also studied by counting the number of characteristic defects that are always produced during the growing process. As expected, the cell quality is improved when the magnetic field is high, the cooling rate is low, the temperature control is accurate, the cell is thick, the sample is passed through the membrane filter and when the annealing time elapses. For the zone-refined sample, however, the cell quality is lowered unexpectedly; the reason for this is discussed.
Formation of Voids in Pure Aluminum Quenched in Hydrogen Gas
Authors: Shimomura Yoshiharu , Moritaki Yoshijiro
Published: November 2005

Pure aluminum foil, nominally 99.999% pure and 50 µm thick, was heated at temperatures between 400°C and 650°C in hydrogen gas by passing direct current and then quenched in a liquid at temperatures between -10°C and 30°C. The number density of voids was examined by electron microscopy. At a constant quenching temperature, the number density was found to be constant for the variation of liquid temperature. In hydrogen at normal pressure, the concentration of voids increased as C
void=A×exp
(-E
void/k
T
Q) with an increase in the quenching temperature T
Q. A was determined to be 0.0011 and E
void=0.86 eV. The number density of voids was found to be proportional to the square root of the partial pressure of hydrogen in a gas. These results indicate that a void is nucleated at the site of a single hydrogen atom dissolved in pure aluminum at high temperature, and that the concentration of voids corresponds to that of hydrogen dissolved in solid solution in pure aluminum.
A Phase Equilibrium Study of Tungsten-Bronze Type Solid Solution in BaO-SrO-Na2O-Nb2O5 System
Authors: Mikami Noboru , Ikeda Takuro
Published: November 2005

Phase equilibria in the quarternary BaO-SrO-Na2O-Nb2O5 system were investigated with particular interest in the tungsten-bronze type solid solution. Curie point and lattice constants of ceramic specimens depended considerably on the firing condition. Based on a careful examination of such effects, distribution maps were determined under a unified firing condition (1350°C, 10 h). Several crystals were pulled from the melts and their compositions were identified referring to these maps. The knowledge of tie-lines enables us to infer the behavior of liquidus and solidus surfaces for the solid solution and suggests the absence of a quaternary azeotropic point.
Phase Diagram of Amorphous and Crystallized Fe-B Alloy System
Authors: Takahashi Minoru , Koshimura Masami , Abuzuka Toshiyuki
Published: November 2005

A study of the structure change with temperature for Fe100-x
B
x
alloys (x=2∼33 at.%B) fabricated by a rapid quenching technique has been carried out by measuring magnetization, electrical resistivity and thermal expansion and also by structural analysis by X-ray diffraction. The amorphous alloys with 11≦x≦13 at.%B transform into α-Fe(B) around 300°C which has a smaller lattice constant than that of α-Fe. Then α-Fe(B) decomposes into two stable α-Fe and Fe2B at about 450°C. For the amorphous alloys with 14≦x≦25 at.%B, the amorphous phase transforms into both α-Fe and tetragonal Fe3B compound at about 400°C. With further heating, an orthorhombic Fe3B compound can be observed clearly in addition to these 2 phases for 17≦x≦25 at.%B. For temperatures beyond 600∼700°C, they transform to the equilibrium phases of α-Fe and Fe2B compound.
Approximate Formulas for a Low-Q Electromechanical Resonator and Their Applications to Electrostrictive PMN-Based Ceramics
Authors: Tsuchiya Yuzuru , Uchino Kenji , Nomura Shoichiro
Published: November 2005

A new approximate method for calculating the electromechanical coupling factors (k
p and k
31) related to transverse vibration in piezoelectric ceramics is proposed, which is applicable to a wide range of coupling factors with a considerable mechanical loss. The induced-piezoelectric resonance was measured by the transmission method on PMN-based electrostrictive resonators under an applied bias field. The electromechanical parameters were determined by using the new approximation in the temperature range -100°C to 100°C under fields up to 12×105 V/m. The electrostrictive Q
31 coefficient obtained is -5.5×10-3 m4C-2 for PMN, which is in good agreement with that determined by other methods.
Multiwire Proportional Chambers with Bidimensional Readout for p̄p Total Cross-Section Measurement
Authors: Iwasaki Hiroyuki , Nakamura Kenzo , Takeda Tsuneaki , Yamauchi Masanori
Published: November 2005

Multiwire proportional chambers with bidimensional readout were used for a low-momentum p̄p experiment. One coordinate was obtained by the usual anode readout and the other by cathode-coupled delay-line readout. The calibration and performance of these chambers under actual experimental conditions are reported with emphasis on the cathode readout.
Analysis of Dark Currents and Minimum Detectable Powers for InGaAsP Optical Receivers
Authors: Takanashi Yoshifumi , Horikoshi Yoshiji
Published: November 2005

The dark current for 1.3 µm InGaAsP and In0.53Ga0.47As avalanche photodiodes was found to consist of two components: (1) a band-to-band tunneling current observed near the breakdown voltage and (2) a generation current at a lower bias voltage. An extensive estimation of the dark current for both diodes is made over a wide range of the donor density for epitaxial wafers on the basis of experimental results. Calculations of the minimum detectable power are made for InGaAsP optical receivers, including avalanche photodiodes and PIN diodes, as a function of various parameters according to the theory by Smith et al. A comparison between minimum detectable powers for avalanche photodiodes and PIN diodes reveals that for λ=1.3 µm, 1.3 µm InGaAsP avalanche photodiodes can provide a better sensitivity than In0.53Ga0.47As PIN diodes whereas for λ=1.5 µm, In0.53Ga0.47As PIN diodes can provide a sensitivity comparable to or better than In0.53Ga0.47As avalanche photodiodes.
Hydrodynamic Description on Double Sheath in Hot-Cathode, Low Pressure Discharge
Authors: Miyajima Shigeki , Kitoh Yoshihiko
Published: November 2005

A double sheath which is normally present in front of a hot-cathode in a low pressure discharge is described on the basis of hydrodynamics. The present theory is compared with Crawford and Cannara's theory and their experiment and good agreement is obtained.
Empirical Formulas for the Backscattering of Light Ions from Solids
Authors: Tabata Tatsuo , Ito Rinsuke , Morita Kenji , Itikawa Yukikazu
Published: November 2005

Empirical formulas have been developed for the backscattering of H, D and He ions normally incident on solid targets. The parameters considered are the number-backscattering coefficient R
N, the energy-backscattering coefficient R
E and the mean fractional energy r
E of backscattered particles (ions and neutrals). The formulation utilizes the fact that the scaling law predicted earlier for R
N and R
E as a function of the Thomas-Fermi reduced energy ε is improved when these parameters are multiplied by S
t/S
e
LSS. Here S
t is the total stopping-power, in which expressions including the Z
2-oscillations are used for the electronic stopping-power, and S
e
LSS is the electronic stopping-power given by the LSS theory when the projectiles are much lighter than the target atoms. The formulas obtained are valid for 10-3\lesssimε\lesssim102.
Far Infrared Spectra in (As2Se3)1-x(Sb2Se3)x Glasses
Authors: Kato Michio , Onari Seinosuke , Arai Toshihiro
Published: November 2005

Far infrared reflectivity spectra in (As2Se3)1-x
(Sb2Se3)
x
(0 ≤x ≤0.4) glasses were studied in the spectral region 80–500 cm-1 at room temperature. Two-mode type behavior of the dominant modes observed in the spectra is shown to be characterized quite well by the local vibrations of As-Se3 and Sb-Se3 pyramidal molecular units. The oscillator strength for the Sb-Se3 unit is ca. 2.5 times larger than that for the As-Se3 unit. Predominance of heterobonding and valency conservation for the elements are deduced from this study. The effective charge e
* for the dominant mode of the Sb-Se3 unit is calculated to be ca. 3.70e which is about 1.7 times larger than that of the As-Se3 unit. The stretching force constants K
As-Se and K
Sb-Se were calculated to be ∼1.77 and ∼1.65×105 dyns/cm, respectively.
Compact Antennas for Lower Hybrid Wave Heating
Authors: Ohshima Shigeki , Takamura Shuichi , Okuda Takayoshi
Published: November 2005

A T-shaped antenna loaded with alumina was designed and constructed for lower hybrid wave heating of toroidal plasmas. The theoretical power spectra showed that a T-shaped antenna can be used for both ion and electron heating, and the accuracy of the calculation was verified by measuring the antenna's impedance. The dependence of the impedance on the power fed to the antenna was also investigated, and it was found that the R.F. pressure affected the coupling between the antenna and the plasma.
Field-Ion Microscope Observation of Thermal Faceting in Ni4Mo Emitter
Authors: Kingetsu Toshiki , Yamamoto Masahiko , Nenno Soji
Published: November 2005

Modes of thermal faceting in emitters of Ni4Mo alloy quenched from the α region (FCC structure) were investigated by field-ion microscopy, using in-situ annealing without an applied field. Faceting with FCC configuration occurred, not only at 1110–1300 K or about 770 K where ordering does not practically occur in bulk, but even at 1100–990 K where nucleation of the β phase (ordered BCT structure) is very active in bulk. At 940–870 K, however, a particular type of faceting occurred at the {751}FCC poles. An interpretation of this faceting was successfully made in terms of crystallography of the ordered structure. Those facets were superlattice {211}BCT facets of the six orientation variants of the β phase. All the variants had equivalently developed. The ordered regions associated with the facets were found to be disc-shaped, a few tens of nanometers in diameter and less than about 2 nm in thickness.
X-Ray Photoelectron and Electron Energy Loss Studies of Si-SiO2 System: Angular Variation
Authors: Ito Toshimichi , Nishikuni Masato , Iwami Motohiro , Hiraki Akio
Published: November 2005

X-ray photoelectron and electron energy loss spectroscopies (XPS and ELS) were performed on silicon with a top oxide layer (\lesssim60 Å) using Mg-Kα radiation and primary electrons with energies of 0.3 to 1.8 keV. The comparison of the experimental results with phenomenological calculations, which contained an assumption that Si-SiO2 couples had a layer structure with an abrupt interface, indicated a good agreement between exprimental and calculated values. Some difference was observed in the polar-angle dependence of XPS and ELS spectra measured using a cylindrical mirror analyzer. This was interpreted as the difference in attenuation length between incident particles, i.e. photons (XPS) and electrons (ELS).
Thermal Quenching and Thermally-Assisted Optical Quenching Effects of Photocurrents in Evaporated Thin Films of β-Copperphthalocyanine
Authors: Mizuguchi Jin
Published: November 2005

The temperature dependence of photocurrents under steady light excitation was investigated in evaporated thin films of β-copperphthalocyanine in the near ultraviolet, visible and near infrared regions under an ultra-high vacuum. Thermal photocurrent-quenching has been observed in every spectral region, and thermally-assisted optical quenching has been newly observed in the near ultraviolet and visible regions. The mechanisms are explained by the scheme that excitons produced by light quanta cannot be dissociated into free carriers in the definite absence of adsorbed gases and that thermal desorption and thermally-assisted photodesorption of these gases cause the thermal and thermally-assisted optical quenchings to occur, respectively. These quenching effects are characteristic of extremely thin films.
Effect of Oxygen and Hydrogen on the Thermal Quenching and Thermally-Assisted Optical Quenching of Photocurrents in Evaporated Thin Films of β-Copperphthalocyanine
Authors: Mizuguchi Jin
Published: November 2005

The effect of oxygen and hydrogen on thermal quenching and thermally-assisted optical quenching of photocurrents in evaporated thin films of β-copperphthalocyanine has been investigated in the spectral region from the near ultraviolet to the near infrared as a function of temperature. Thermal quenching and optical quenching were observed in an oxygen atmosphere under near ultraviolet and visible excitations, and their onset temperatures were slightly higher than those under an ultra-high vacuum. Hydrogen, however, inhibits the thermal quenching and thermally-assisted optical quenching; no thermal quenching was observed in any region investigated, and only slight optical quenching occurred at high temperatures under the excitation of near ultraviolet light. This effect can be ascribed to the fact that hydrogen, adsorbed tenaciously on the surface, still acts as a dissociator of excitons without being desorbed even at high temperatures and under intense illumination.
Magnetization Process of Exchange-Coupled Ferrimagnetic Double-Layered Films
Authors: Kobayashi Tadashi , Tsuji Hisao , Tsunashima Shigeru , Uchiyama Susumu
Published: November 2005

Magnetization curves are theoretically calculated for exchange-coupled ferrimagnetic double-layered (ECDL) films, each layer of which has a uniaxial anisotropy with the easy axis perpendicular to the film plane and exhibits a rectangular hysteresis loop. With this model are obtained the conditions for the appearance of anomalous and inverted hysteresis loops observed by the Kerr magneto-optic method. Experiments are made on Gd-Fe/Tb-Fe double-layered films deposited successively in a vacuum better than 10-6 Torr. By comparing the experimental switching field for the Gd-Fe layer in ECDL films with the theory, the energy density of the interface wall is estimated to be 1–2 erg/cm2.
Study on Measurement of Carrier Effective Lifetime in Furnace and Laser Annealed Diodes
Authors: Rahman Mohammad Mahmudur , Furukawa Seijiro
Published: November 2005

A new and simple method by which it is possible to separate the bulk generation-recombination current from the externally flowing edge leakage current of ion implanted p-n mesa diodes is introduced. Using this method, the value of the carrier lifetime as well as its profile along the depth is determined. Having demonstrated the effectiveness of this new method for furnace annealed samples, investigations were then carried out for laser annealed ones. It was observed from the results obtained from laser annealed (Q-switched, Ruby) diodes that the lifetime does not vary with depth at energies greater than 1.6 J/cm2. In this energy region, the lifetime becomes longer as the energy is increased reaching an optimum at 2.05 J/cm2, after which a further increase in energy causes a sudden shortening of the lifetime.