bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Device Parameters on a Photoelectrophoretic Display System
Authors: Nakamura Kenichi , Kuroiwa Masao , Nishitani Akito , Iwanari Yoshiyuki
Published: November 2005

The device parameters of photoelectrophoretic display cells with a photoconductor electrode were varied, and the optical characteristics viewed through the front and rear electrodes were measured. The behavior of ions in the suspension as well as that of pigment particles is found to be an important factor in the formation of images. Also, when a smaller amount of particles is present, carrier injection from the photoconductor to the particles has an undesirable effect on the image contrast, particularly at higher voltages and exposures. This effect is significantly diminished by employing an insulator-coated photoconductor electrode. The results obtained are discussed here, using a multilayer model for the pigment particles.
Measurement of Magneto-Optical Kerr Effect Using Piezo-Birefringent Modulator
Authors: Sato Katsuaki
Published: November 2005

An advanced magneto-optical technique is described, which allows simultaneous determination of two mutually-conjugate parameters–Kerr rotation and reflectance magneto-circular dichroism–using a piezo-birefringent modulator. This technique provides a sensitivity of 0.002° for Kerr rotation at λ=500 nm with 12 nm resolution, using a halogen lamp (150 W) as the light source. The wavelength region covered by the method can be extended from 300–2500 nm by suitable selection of gratings and light detectors. The new technique was used to measure magneto-optical hysteresis loops for several wavelengths and magneto-optical spectra on an rf-sputtered amorphous Gd-Co film, and the results are reported here.
Flow Visualization of a Two-Dimensional Water Jet in a Rectangular Channel
Authors: Ouwa Yasuhiro , Watanabe Masaaki , Asawo Harumi
Published: November 2005

The flow patterns of a two-dimensional water jet in a rectangular channel are studied in detail by the method of colored emission. The transition from symmetric to asymmetric flow and the dynamic behavior of the flow patterns are studied for various different cases and qualitative explanations are given.
Influence of Mechanical Vibrations on Microscopic Growth Rates in GaSb Pulled Crystals
Authors: Quang Nguyen V. , Hayakawa Yasuhiro , Kumagawa Masashi
Published: November 2005

GaSb single crystals were pulled from the melt by the Czochralski method. During growth, mechanical vibrations with a small velocity amplitude and a constant periodicity were transmitted to the pulling rod in order to investigate the influences on the microscopic growth rates. It was found that the influence of mechanical vibrations on the amplitude of variation of growth rates decreased when the crystal diameter or the pulling rate was increased. On the other hand, thermal convection currents and/or forced convection currents which lead to irregular variations of the microscopic growth rate at the off-faceted region have no effect on the faceted region.
Pierce-Type Electron Gun with a Large Concave LaB6 Cathode
Authors: Shintake Tumoru , Ohba Kunio , Matoba Masaru , Katase Akira
Published: November 2005

A Pierce-type electron gun with a concave cathode of lanthanum hexaboride (LaB6) 30 mm in diameter is described. At an accelerating voltage of 3 kV and a cathode temperature of 1340°C, a focussed electron beam of DC 300 mA was obtained.
Deep Impurity Levels in InP LEC Crystals
Authors: Yamazoe Yoshimitsu , Sasai Yoichi , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

Deep impurity levels in InP LEC single crystals have been investigated by deep-level transient spectroscopy (DLTS) and photoluminescence (PL) measurements. The effects of heat treatment on DLTS and PL signals have been investigated, the results indicating that a deep impurity level whose emission activation energy is 0.42 eV is closely related to the well-known PL emission band at 1.1 eV. It seems that these DLTS and PL signals originate from a certain complex including P vacancies and defects, since some behaviours of these signals can be well explained by a configuration-coordinate model. Two other deep levels with emission activation energies of 0.31 and 0.60 eV have also been observed. The origin of these deep impurity levels might be due to native defects in the InP LEC crystals.
Magnetic Properties of Plastically Deformed Iron Single Crystals
Authors: Maruyama Hiroko , Takeuchi Tomoyuki , Nosé Hiroshi , Ōyama Isao
Published: November 2005

Iron single crystals were elongated along the [001] and [011] axes at temperatures of -78, -50, 22 and 200°C, and their magnetization curves were measured using picture frame specimens. The [011] crystal elongated at 22 and 200°C showed a large increase in coercive force H
c, and the [001] crystal elongated at -50°C showed a small increase in H
c in spite of considerable work-hardening.
It is concluded that the main origin of the increase in H
c is not dislocation densities, but the local crystal misorientation between neighboring cells which develops with the increase of deformation.
On the Studies of Solid Solution Hardening
Authors: Suzuki Taira
Published: November 2005

A historical survey of progress in the study of solid solution hardening is given, and then the present state of knowledge is explained. The advances in statistical treatment related to the motion of dislocations through random arrays of solute atoms promoted by the recent discovery of inertial effects is most spectacular.
Raman and Infrared Spectra of Rhombohedral Selenium
Authors: Nagata Kiyofumi , Ishibashi Katsunori , Miyamoto Yasuhiko
Published: November 2005

Raman and infrared spectra of rhombohedral selenium have been measured and the fundamental bands observed in these spectra are assigned by analogy to the S6 ring molecule. Calculation of the normal mode vibration for the Se6 ring using a modified Urey-Bradley force field confirms this assignment.
Anomalous softening of the A1g stretching mode relative to other modes and to the corresponding A1 mode in the Se8 ring was observed. This phenomenon is explained by the idea of interference of inter-molecular interaction with the intra-molecular bonding.
Comparison of the observed spectra of rhombohedral selenium with those of other allotropes (α-monoclinic, trigonal, and amorphous selenium) suggests that Se6 ring molecules may exist in amorphous selenium.
Crystal Structure and External Shape of Fine Particles of Beryllium Produced by Evaporation in Inert Gases at Low Pressures
Authors: Fukano Yasushige , Nakao Katsuji
Published: November 2005

It has been found by electron microscopy and electron diffraction that fine particles with the monoclinic lattice are formed in beryllium smoke produced by the evaporation of beryllium metal in inert gases at low pressures. The lattice constants are determined as a=5.49, b=6.10, c=4.10 Å and β=98.5° within an error of 0.2%, the space group is either Cs
4 or C2h
6, and the external shape of the particles is very like a rhombic dodecahedron. This monoclinic beryllium is a new allotrope of beryllium. Rhombic dodecahedral particles of α-beryllium are also found, produced from the monoclinic particles by martensitic transformation.
Cleavage Steps from Screw Dislocations of Inclusion-Growth Spiral Pairs in Stearic Acid Crystal
Authors: Sato Kiyotaka , Komikado Masanori , Okada Masakazu , Seto Tsuneo
Published: November 2005

The existence and structure of screw dislocations along the long-chain axis were examined by a careful cleavage technique, in order to characterize the inclusion-growth spiral pairs in stearic acid crystals grown from solution. First, the correspondence between various kinds of dislocation etch pits and the originating centers of cleavage steps on the basal {001} planes was confirmed. Then the cleavage step structures were observed with a reflective Nomarski interference microscope on planes which were created by cutting the crystal between the growth spiral steps and the inclusions. The features of the originating points and the geometrical step structures of the cleavage steps are discussed in relation to the morphological characteristics of the inclusion-growth spiral pairs. As a result, the existence of screw dislocations in the inclusion-growth spiral pairs was clearly confirmed.
Mixing Effects on the Cotton-Mouton Constant of 3OCB and 5OCB in Isotropic Phase
Authors: Muta Ken-ichi , Takezoe Hideo , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

To find a material with large magnetic-field-induced birefringence Δ
n/H
2, we have studied the mixing effects on K
C and (Δ
n/H
2)
T=T
c
of 4'-n-propyloxy-4-cyanobiphenyl (3OCB), which has the largest value of K
C, and 4'-n-pentyloxy-4-cyanobiphenyl (5OCB), which has the largest value of (Δ
n/H
2)
T=T
c
among the cyanobiphenyls so far investigated. Here K
C is the proportionality constant in the relation Δ
n/H
2=K
C/(T-T
c
*); (Δ
n/H
2)
T=T
c
is necessary because the relation may not hold as the temperature approaches the clearing point T
c. The mixing is effective and both K
C and (Δ
n/H
2)
T=T
c
attain the maxima at x=0.2 and 0.6, respectively, where x=[5 OCB]/([3 OCB]+[5 OCB]). The phase field in which the isotropic and nematic phases coexist appears to be less than 0.07°C. The K
C(x) and T
c(x) curves have mirror symmetry with respect to a line parallel to the abscissa; larger K
C corresponds to lower T
c. To understand their dependence on x, we have also discussed what phenomenological parameters in the Landau-de Gennes theory are responsible for K
C and (Δ
n/H
2)
T=T
c
.
Photoelectronic Properties of p-Type CdTe in an Aqueous Solution
Authors: Nashimoto Yasunobu , Fuyuki Shigeru , Akutagawa Tadamasa , Hayakawa Sohachiro
Published: November 2005

The current-potential relations under monochromatic irradiation and the quantum efficiency-wavelength relations of p-type CdTe with different acceptor concentrations have been measured in a 0.1 N NaOH solution. The photocurrent was observed under cathodic polarization and the photoresponse spectra agreed approximately with those estimated theoretically. The quantum efficiency was found to be strongly affected by surface recombination, and it had a maximum value of 0.85 with an N
a acceptor concentration of about 1016 cm-3.
Lattice Distortion and Magnetic Inhomogeneity in Fe-Ni Invar Alloy
Authors: Arai Juichiro
Published: November 2005

X-ray diffraction and magnetization measurements were carried out on Invar alloy with magnetic inhomogeneity over the temperature range from room temperature to 400°C.
The temperature dependence of the lattice strains on the (311), (220) and (200) planes were calculated from the diffraction line breadths. It was found that the average lattice strain (Δ
d/d) at room temperature amounts to 1.17×10-3 and almost vanishes above the Curie temperature, and furthermore the temperature dependence is similar to the temperature dependence of the magnetization. The origin of the large lattice-distortion is discussed on the basis of the anomalous magnetovolume effect and the related lattice instability in Invar composition.
Structural Changes and Melting Behavior of γ-Irradiated Polyethylene
Authors: Kato Kazuo , Ametani Kazuo , Imai Masahiko , Seto Tsuneo
Published: November 2005

The structural changes and melting behavior of high density polyethylene irradiated at room temperature were studied by X-ray diffraction and differential scanning calorimetry up to about 4000 Mrad. The melting point and the heat of fusion were depressed by irradiation. A monotonic lattice expansion and an increase in overall specific volume with increasing dose, which lead to a decrease in the specific volume of the amorphous region, were also observed. These changes are thought to be caused by the formation of crosslinks near the surfaces of crystallites and in the amorphous region. The melting point depression can be explained by the effects of lattice distortion and crosslinks outside the crystallites introduced by irradiation. Above 1000 Mrad, a phase transformation into the hexagonal form was observed below the melting point.
Threshold Gas Flow Rate of Halide Materials for the Formation of Oxide Particles in the VAD Process for Optical Fiber Fabrication
Authors: Kawachi Masao , Sudo Shoichi , Edahiro Takao
Published: November 2005

The state of oxides produced by the flame hydrolysis reaction of halide materials, in particular whether the oxides exist as vapor or as solid particles in the oxy-hydrogen flame, is investigated because of its connection with the VAD process for optical fiber fabrication. Each halide gas is found to have a threshold flowrate below which the oxide product does not form solid particles in the flame but remains in the vapor state. The threshold flowrate of halide materials examined in this work is in the order TiCl4, SiCl4<GeCl4, BBr3<SnCl4<PCl3. This peculiar order is dominated by the saturated vapor pressure values of the oxides produced at high temperatures in the flame. The relation between the experimental results and the refractive-index formation mechanism in the VAD process is discussed.
The Effect of Reducing Gases on the Conductivities of Metal Oxide Semiconductors
Authors: Yamamoto Naoto , Tonomura Shoichiro , Matsuoka Tsugufumi , Tsubomura Hiroshi
Published: November 2005

The electrical resistance of a disk of silver oxide (Ag2O) decreases enormously at room temperature when it is exposed to carbon monoxide gas. Using this effect, carbon monoxide in air can be detected selectively and quantitatively over a wide range from 10 ppm to 105ppm. The direction of the change in resistance due to carbon monoxide is difficult to explain from a simple adsorption model of electron-donating gases on a semiconductor if Ag2O is assumed to be a p-type semiconductor. We conclude that this change can be explained by taking into account the reduction of the Ag2O surface by carbon monoxide. A similar resistance change due to carbon monoxide has been found in p-type CoO, MnO2and NiO.
Properties of Amorphous Iron-Metalloid Thin Films
Authors: Tsunashima Shigeru , Mitsuya Seishiro , Uchiyama Susumu
Published: November 2005

Amorphous Fe-B, Fe-Si-B, Fe-B-C and Fe-Si-C films 0.6 to 0.9 µm thick were prepared by the r.f. sputtering technique. The metalloid content in the films was varied in the range 10 to 30 atm.% and the soft magnetic properties and thermal stabilities were investigated. In the as-prepared state, most of the amorphous films had coercivities of less than 1 Oe. On annealing in a magnetic field, the coercivity of Fe80B20 and Fe73Si18C9 films decreased to 0.04 Oe. The anisotropy energy induced by the field annealing at 300°C is 3 to 5×103 erg/cm3, which is much larger than those of melt-quenched alloys. In thermal stability, Fe-B, Fe-B-C and Fe-Si-B films are nearly the same as or slightly worse than corresponding melt-quenched alloys, while Fe-Si-C films, which have not yet been prepared in ribbon form, have good thermal stability and continue to exhibit low coercivity after annealing at 400°C.
Computer-Aided Spot Indexing for X-Ray Laue Patterns
Authors: Ohba Ryoji , Uehira Ichiro , Hondoh Takeo
Published: November 2005

A method that applies pattern recognition techniques to the computer-aided indexing of X-ray diffraction spots is proposed. The indices of a set of spots are determined based on an analysis of the set of mutual angles between every pair of reciprocal lattice vectors corresponding to those spots. The method is applied to the automatic determination of the crystallographic orientation of an ice crystal.
Adsorption of CO on Iron Single Crystal Surfaces
Authors: Yoshida Kiyohide
Published: November 2005

The adsorption of carbon monoxide on a stepped Fe(111) surface around 300 K was studied by low energy electron diffraction, thermal desorption spectroscopy and Auger electron spectroscopy. Similar detailed experiments on Fe(110) and (111), some of which were reported in Surf. Sci. 75 (1978) 46, were also performed.
On a stepped (111) surface, CO adsorption produced a diffuse pattern very similar to the (1×1) pattern obtained with a flat (111) surface. Thermal desorption spectra from the stepped (111) surface showed two kinds of desorption states, α- and β-CO, as from the (110) and (111) surfaces, which are ascribed to molecularly and dissociatively adsorbed CO, respectively. The spectra also showed that the catalytic activity of C-O bond breaking was higher on the stepped (111) surface than on the (111) and (110) surfaces. The effect on CO adsorption of residual carbon on iron surfaces is almost negligible, while that of residual oxygen is high.
Cathodoluminescence of Terbium Activated Metaphosphate Glasses
Authors: Takahashi Tatsuo , Yamada Osamu
Published: November 2005

Cathodoluminescent properties of several alkali and alkaline earth terbium metaphosphate glasses were investigated at an applied voltage of 100 V to 2500 V in a vacuum diode structure. Light outputs were compared with that from a Zn2SiO4:Mn (Pl) phosphor.
Performance of Magnetic Filter for HGMS
Authors: Hiresaki Yū , Sekizawa Kazuko , Yasukōchi Kō
Published: November 2005

The performance of a grid filter and a stainless-steel wool filter for high-gradient magnetic separation was investigated and compared with theoretical results based on the particle trajectory model using a potential flow scheme. The results on the grid filter agree with the theoretical ones quantitatively, but the results on the stainless-steel wool filter agree with the theory only qualitatively; the reduced capture radius is less by about one order of magnitude than that of the theory. The time dependence of the performance of the grid filter is consistent with the theory.
Anomalous Differential Capacitance of the Schottky Barrier on a Semiconductor with Electric-Field-Dependent Dielectric Constant
Authors: Miyazaki Tomoyuki , Hideshima Osamu
Published: November 2005

The differential capacitance C of a Schottky barrier with bias voltage V
a is derived for the case that near the surface of the semiconductor there are two regions with different electric-field-dependences of the dielectric constant. The d(1/C
2)/dV
a vs V
a characteristics is found to show discontinuity when the edge of the depletion layer passes the boundary between the two regions.
A Measurement System for Interior Projectile Motion and Particle-Velocity Histories for Impact Shock Study with a Two-Stage Light Gas Gun
Authors: Mashimo Tsutomu , Sawaoka Akira
Published: November 2005

This system has been developed for the purpose of precise observations of shock-compression states at pressures higher than several 10s of GPa in solids. Plane impact experiments within an impact tilt-angle of 0.2 degrees, in which the impact velocity can be measured within an error of 0.5% by the X-ray beam cut-off method, are made practicable. Particle-velocity histories at two points were measured by the electromagnetic-gauge technique, within an error of 2% up to a pressure of 59.4 GPa in sapphire and stabilized zirconia.
A Versatile Photostimulated Exoelectron Emission Microscope as Applied to Observing Mechanical Damage on Aluminum Surfaces
Authors: Yamamoto Shigeyuki
Published: November 2005

A photostimulated exoelectron emission microscope has been developed, which enables us to observe mechanically-damaged surfaces in two modes; in one mode it forms a direct image on a phosphor screen by means of an electron optics system including an image intensifier, and in the other it indicates the spatial distribution of the emission intensity or of an electron energy spectrum obtained by scanning the specimen surface with a light spot.
Through observation of aluminum surfaces damaged either by tensile deformation or by friction, it has been demonstrated that the microscope can be operated as easily as a scanning electron microscope and the exoelectron image gives information as to how fresh and critical each damage is.
Optical Emission Spectroscopy of the SiH4-NH3-H2 Plasma during the Growth of Silicon Nitride
Authors: Yokoyama Shin , Hirose Masataka , Osaka Yukio
Published: November 2005

Optical emission spectroscopy of the SiH4-NH3-H2 glow discharge revealed the presence of the reactive species, Si, SiH, NH, H, and H2 in the plasma. The silane flow rate dependence of the emission intensities from these species has been well correlated with the growth rate of the resulting Si:N:H films and their compositional ratio of silicon to nitrogen. Furthermore, the numbers of SiH and NH bonds incorporated in the film are found to be proportional to the emission intensities of the SiH band and NH line, respectively. The growth mechanism of Si:N:H from the reactive SiH and NH molecules is discussed from these results.
Preparation of Ge-S Glass Fibers with Reduced OH, SH Content
Authors: Shibata Shuichi , Manabe Toyotaka , Horiguchi Masaharu
Published: November 2005

Content of OH and SH impurities in Ge-S glasses, which have disturbed the development of low-loss Ge-S glass fibers in the 3–6 µm wavelength region, are reduced by heating the starting materials at 400–500°C under S2Cl2 vapour flow. The absorption losses caused by the OH and SH impurities are lowered one-fourth of the initial values. Optical losses lower than 1 dB/m are achieved at four wavelengths: 2.4, 3.3, 4.7 and 5.1 µm.
Hot Electron Transport Inhibition and Density Modification due to Electrostatic Field
Authors: Yabe Takashi , Mima Kunioki , Yoshikawa Kazuhiko , Takabe Hideaki
Published: November 2005

It is found that an assumed anomalous electron collision rate gives rise to a strong electrostatic field and Joule heating of the cold electrons in laser-produced plasmas. As a result of these anomalous processes, a steep density jump is created near the critical point. This phenomenon is investigated by computer simulation, the results of which qualitatively agree with a simplified theoretical model.
Self-Sustained Pulsation Appearance in InGaAsP/InP DH Lasers during Accelerated Operation
Authors: Fukuda Mitsuo , Wakita Koichi , Iwane Genzo
Published: November 2005

Self-sustained pulsation (SSP) has been observed in InGaAsP/InP double heterostructure (DH) lasers during accelerated operation. The development of SSP depends on the number and absorption coefficient magnitude of dark defects associated with degradation. The absorption coefficient of a dark defect that induces SSP is experimentally estimated to be from 300 to 600 cm-1. The frequency of the SSP is a linear function of the square root of the current density. The fact that dark defects in the active region are one origin of SSP in InGaAsP/InP lasers, as well as AlGaAs/GaAs lasers, is made clear.
Lateral Epitaxial Growth in Poly-Si Film over SiO2 from Single-Si Seed by Scanning CW Ar Laser Annealing
Authors: Sakurai Junji , Kawamura Seiichiro , Mori Haruhisa , Nakano Motoo
Published: November 2005

CVD poly-Si films 0.4 µm thick were deposited on (100) Si-substrate having a thermally grown SiO2 0.4 µm thick. The samples were then annealed to melt and recrystallize the poly-Si films with scanning cw Ar laser. Laser-annealing in a unidirectional mode with overlapped beams was found to produce a single crystal (100) Si as large as 36 µm in maximum width and more than 140 µm in length in the poly-Si film on SiO2 along the Si seed. However, the lateral epitaxial growth was restricted in size by formation of long crystallites from unannealed poly-Si peripheries and of grain boundaries probably due to the stresses generated by the poly-Si/SiO2 interface.
Impurity Absorption Loss due to Rare Earth Elements in a Fluoride Glass
Authors: Ohishi Yasutake , Mitachi Seiko , Shibata Shuichi , Manabe Toyotaka
Published: November 2005

Optical spectra for each of the rare earth element doped BaF2-GdF3-ZrF4 glasses were measured. It was found that, in the 2–5 µm wavelength region, Ce, Pr, Nd, Sm, Tb and Dy contribute to the absorption loss and the loss magnitude due to each rare earth element of lppmw is several tens of dB per kilometer at the absorption peaks. It was concluded that the rare earth impurity concentration in fluoride optical fibers should be decreased to less than 0.1 ppbw in order to make the absorption loss 10-3 dB/km in the 3–4 µm wavelength.
The Effect of Ion Bombardment on Carbon Films Prepared by Laser Evaporation
Authors: Fujimori Susumu , Nagai Kazutoshi
Published: November 2005

Carbon films have been prepared by laser evaporation of powdered graphite simultaneously with Ar ion bombardment on a deposited substrate. The effect of the ion bombardment on film properties, composition and structure has been investigated. Films with higher transmittance, resistivity and hardness are obtained by simultaneous ion bombardment, and are supposed to present a random network structure.
Simplified Dual Channel Optical Transmission Using Integrated Light Emitters and Photodetectors
Authors: Sakai Shiro , Aoki Takahiro , Tobe Miharu , Umeno Masayoshi
Published: November 2005

The simplified dual channel wavelength division multiplexed (WDM) system that uses a two-color LED and wavelength demultiplexing photodiode is tested. The total crosstalks at shorter (1.13 µm) and longer (1.36 µm) wavelength channels are -15 dB and -17 dB, respectively, which are determined by the spectral crossover of emission spectra of the LED and the spectral sensitivities of the photodetector. The possibility of the WDM system that does not need a “multiplexer” and “demultiplexer” is demonstrated in this letter.
Experiments of MHD Activities of Low Modes in the Heliotron-D
Authors: Kinoshita Shigeyoshi , Motojima Osamu , Iiyoshi Atsuo , Uo Koji
Published: November 2005

Experiments of current-driven magnetohydrodynamic activities are performed in the Heliotron-D, which has a large rotational transform that is greater than unity and a strong shear. It was found that the dominant modes of the MHD activities are M=1 modes, where M is a poloidal mode number, and that they have different properties for the direction of the plasma current. The experimental results agree well with the theoretical expectations.
Contribution of Some Metallic Electrodes to TGS Domain
Authors: Izumi Nagahide
Published: November 2005

Effect of some metallic electrodes on ferroelectric domain structure in (010) plate of TGS has been observed by a carbon depositing technique. It is found that dislocations can be produced at desired sites by the use of an electrode which was evaporated with gold through a sheet mesh and was painted with Ag paste. The magnitude of stress field around these dislocations may be very large and these dislocations act as seeds when the domains are reformed.
Relation between Polarity of Substrate Surface and Liquid Crystal Molecular Orientation
Authors: Ohgawara Masao , Uchida Tatsuo
Published: November 2005

A new method to measure the polarity of the substrate surface by applying the principle of chromatography is proposed. By using this method, the relation between the liquid crystal molecular orientation and the polarity of the substrate surface is made clear. That is, liquid crystals with amphiphilic impurities align perpendicular to the strong polar surfaces such as In2O3 or Al2O3.
Improvement of Crystalline Quality of SOS with Laser Irradiation Techniques
Authors: Kobayashi Yutaka , Suzuki Takaya , Tamura Masao
Published: November 2005

The crystalline quality of silicon layers grown on sapphire substrates by vapor-phase epitaxial growth is improved by exposing the layers to multiple doses of laser irradiation of a suitable energy density. SOS wafers have been irradiated with 25 ns pulses from a Q-switched ruby laser. The samples have been analyzed by Hall mobility, defect density and channeling. The electron Hall mobilities of samples exposed 2–4 times at an energy density of 1.5 J/cm2 are twice those of as-grown SOS. Under the same conditions, etch pit density and stacking fault density decreased by a factor of 3–4 and 10, respectively.
Continuous Growth of High Purity InP/InGaAs on InP Substrate by Vapor Phase Epitaxy
Authors: Susa Nobuhiko , Yamauchi Yoshiharu , Kanbe Hiroshi
Published: November 2005

Growth conditions and crystal properties for InP and InGaAs layers successively grown by vapor phase epitaxy are described. After InGaAs lattice-matched to a (100) InP substrate is deposited, InP is successively grown by using a sliding substrate holder and changing the growth temperature profile. Optimum growth conditions to reduce etch pit density and unwanted interface states at the heterointerface are discussed. Planar InP/InGaAs photodiodes fabricated from grown crystals have dark current density of 2.4×10-5 A/cm2 at -40 V. Carrier densities for InP and InGaAs are about 3.5×1015 cm-3, which is suitable for photodiodes with small capacitance.
Characteristics of the Relief Patterns in Ion-Beam Lithography
Authors: Grigaitis P. , Pranevi\ucius L.
Published: November 2005

Characteristics of the relief patterns of negative and positive resist materials in ion-beam lithography are determined. It is found that the same resist materials are more suitable to exposure by ions than by electrons. Relief patterns of positive resist have a high resistivity to plasma-chemical etching. The relief pattern view observed with a scanning electron microscope is demonstrated.
Li-Ti-O Superconducting Compounds Prepared by Hot-Pressing
Authors: Inukai Takashi , Murakami Toshiaki , Inamura Takahiro
Published: November 2005

Dense Li-Ti-O ceramics were prepared by hot-pressing of mixtures of Ti2O3 and Li2Ti2O5 in order to investigate the relation between superconducting properties and preparation conditions. They become superconducting in the Ti/Li atomic ratio range of 1.5–3.1 at a hot-pressing temperature of about 900°C, or in the temperature range of 870–970°C at an atomic ratio of 2.0. The highest T
c of 13.4 K (onset 13.8 K) is obtained on the sample prepared at 900°C and at an atomic ratio of 2.6.
Organometallic Vapor Phase Epitaxial Growth of In1-xGaxP (x ∼0.5) on GaAs
Authors: Yoshino Junji , Iwamoto Takashi , Kukimoto Hiroshi
Published: November 2005

In1-x
Ga
x
P (x∼0.5) layers have been grown on GaAs by low-pressure vapor phase epitaxy using triethylindium (TEI), triethylgallium (TEG) and phosphine. The observation of surface morphology and the measurements of peak energy and half-width of photoluminescence spectra indicate that high quality layers lattice-matched to GaAs substrates can be grown by controlling the substrate temperature and the TEI and TEG flows. The best sample has shown a room-temperature photoluminescence efficiency comparable to that of LPE layers of the same composition.
InSb1-xBix Films Grown by Molecular Beam Epitaxy
Authors: Oe Kunishige , Ando Seigo , Sugiyama Koichi
Published: November 2005

InSb1-x
Bi
x
thin films were grown on InSb substrates by molecular beam epitaxy. The band-gaps of the films were confirmed to shift to longer wavelength with the increase of InBi mole fraction in the films by the measurement of p-n junction photovoltaic response.
Ultrasonic Shear Mechanical Impedance of Smectic-A Liquid Crystals
Authors: Kawamura Yasuaki , Okano Koji , Iwayanagi Shigeo
Published: November 2005

The ultrasonic shear mechanical impedance of octyloxy cyanobiphenyl and cyanobenzylidene octyloxyaniline was measured by the torsional quartz crystal method. The measured impedance suggested a finite shear elasticity in the smectic-A phase, which was interpreted as an evidence of the existence of the finite smectic layer compression modulus giving rise to a propagating “second sound mode”. From the impedance the smectic layer compression modulus was evaluated as ∼107 cgs for both compounds and it showed a pretransitional decrease as the nematic phase was approached.
Electro-Optical Effects in LC (MBBA) Sandwich Cell Including a Micropore Membrane
Authors: Yatsuzuka Kyoko , Watanabe Akira
Published: November 2005

Light-scattering characteristics for DSM in two types of cell, one that includes the micropore membrane and the other that does not, were compared. The scattered light is not observed when a voltage is applied directly to the LC columns in micropores of the membrane, however, if an LC layer is introduced between one side of the membrane and the nesa glass, the light-scattering phenomenon is noted. The results show the possibility of the growth of higher order agitations of the LC molecules in the former type cell. The LC cell including a micropore membrane can be utilized for high speed display or light valve devices.
Time Dependent Dielectric Breakdown of Thin SiO2 Films
Authors: Hirayama Makoto , Asai Sotoju , Matsumoto Heihachi , Sawada Kokichi , Nagasawa Koichi
Published: November 2005

Time dependent dielectric breakdowns (TDDB) of thin SiO2 films are described. The breakdowns are composed of two logarithmic normal distributions having different mean time to breakdown. One is area dependent and the other is independent. With increasing the area of capacitors the distribution of dielectric breakdowns shifts toward only one logarithmic normal distribution dominated by the area dependent breakdown having the shorter mean time to breakdown. The results are compared with usual voltage ramping method. In addition, electric field acceleration factor is measured 102.7/MV/cm for the area dependent mode and 105/MV/cm for area independent mode. The thickness dependence is also described.
Surface Structure of Si(111)- √3 ×√3-Ag Studied by Averaged LEED Analysis
Authors: Terada Yasushi , Yoshizuka Tohru , Oura Kenjiro , Hanawa Teruo
Published: November 2005

Low energy electron diffraction constant momentum transfer average (LEED/CMTA) technique has been applied to the Ag/Si(111) surface. The specularly reflected (00) beam analysis for the Si(111)- √3×√3-Ag structure verifies the recently proposed model where the ordered Ag layer is embedded below the topmost Si layer. A considerable displacement of the Si subsurface is also suggested.
Electron Spin Resonance in Discharge-Produced Silicon Nitride
Authors: Yokoyama Shin , Hirose Masataka , Osaka Yukio
Published: November 2005

ESR signal from the defects in plasma-deposited silicon nitride has been observed, for the first time. The g-value (2.0055) is identical with that of silicon dangling bonds in amorphous Si:H, and the linewidth (14.5 G) is two times as large as that of amorphous Si:H for spin densities below 1018 cm-3, above which narrowing of the linewidth takes place as in the case of amorphous Si:H. It is suggested that most of dangling bonds of nitrogen atoms in the silicon nitride are passivated by bonded-hydrogen and silicon dangling bonds are mainly responsible for the ESR signal. A correlation between the spin density and leakage current through the film is also discussed.
An Application of Dye-Laser-Induced Fluorescence Technique to Absolute Calibration of a Vacuum Monochromator
Authors: Oda Toshiatsu , Usui Tatehito
Published: November 2005

An application is decribed of the dye-laser-induced fluorescence technique to improve the atomic branching ratio method of the absolute calibration of a vacuum monochromator and detector system. A model experiment shows that a new type of line pair, such as the Hαand the Lαline, of which the VUV line originates from the lower energy level in a transition relating to the visible or the near ultra-violet line, can be used for calibration by using the optical pumping technique.
A Dispersive Method of Measuring Extended X-Ray Absorption Fine Structure
Authors: Kaminaga Ukyo , Matsushita Tadashi , Kohra Kazutake
Published: November 2005

A novel method of EXAFS measurement has been developed, in which all the data points of a spectrum are collected simultaneously. A convergent X-ray beam, whose energy varies with beam direction, is realized with a transmission-type (Laue-case diffraction) crystal disperser. By measuring the spatial intensity distribution across the beam path behind the focus at which the specimen was placed, an EXAFS spectrum of an iron metal foil is measured in about 15 hr with a statistical accuracy better than 0.16% using a sealed-off X-ray tube operated at 15 keV and 35 mA. Some measures to shorten the measuring time to the order of minutes are discussed.
Computer Aided Detection of Slow Motion of Defects in GaP Light Emitting Diodes
Authors: Ogura Mutsuo , Sakaue Katsuhiko , Takagi Mikio , Adachi Yoshio , Ikoma Toshiaki
Published: November 2005

Light emitting diodes usually degrade nonuniformly in space and it is needed to analyze a change of light intensity distribution in order to investigate in depth the degradation mechanism. We show here that the digital image processing technique is a powerful tool to analyze quantitatively a change of light intensity pattern and can detect a very small and slow motion of defects by visualizing the “degradation velocity pattern”.
Relief of Residual Strain in Silicon-on-Sapphire by Heat-Assisted Pulsed-Laser Annealing
Authors: Yamazaki Ken-ichi , Yamada Masayoshi , Yamamoto Keiichi , Abe Kenji
Published: November 2005

Heat-assisted pulsed-laser annealing is proposed to relieve residual strain in silicon-on-sapphire (SOS). It is performed by irradiating Q-switched ruby laser light to Si-ion-implanted SOS samples while they are thermally heated. It is found from Raman scattering measurements that the residual strain is relieved by annealing with the laser energy density of 1 J/cm2 to 3 J/cm2 at the heating temperature of 400°C to 500°C.
Bistable Optical Device Using the Electrostrictive Displacement Transducer
Authors: Gomi Manabu , Uchino Kenji , Abe Masanori , Nomura Shoichiro
Published: November 2005

A bistable optical device of a Fabry-Perot-resonator type with nonlinear feedback have been made using the PMN electrostrictor. The output light intensity of this device exhibits much more reproducible bistability with respect to input intensity than in the hard PZT piezoelectric device. Nearly constant transmitted power can be obtained over a wide range of input power.
Relaxation of Amorphous Gd-Co Films through Electrical Resistivity Measurement
Authors: Kajiura Masako , Togami Yuji , Kobayashi Kikuo , Teranishi Teruo
Published: November 2005

Irreversible decrease of electrical resistivity in an amorphous Gd-Co alloy film has been observed and is analyzed assuming a simple relaxation process. An apparent activation energy of 0.5 eV is obtained.
Experiment on the Extraction of Microwave Pulses from a Superconducting Cavity
Authors: Minami Kazuo
Published: November 2005

Microwave pulses are extracted from a superconducting cavity by changing mechanically the coupling factor to the output circuit. The peak output power is about 10 times that of the steady state. The results are explained fairly well by theoretical analysis. Possible improvements for obtaining high peak powers are discussed.
Measurements of the Dispersion Relation of the Low-Frequency Ion Acoustic Instability in the Turbulently Heated TRIAM-1 Tokamak Plasma
Authors: Mitarai Osamu , Watanabe Takechiyo , Nakamura Yukio , Nakamura Kazuo , Hiraki Naoji , Toi Kazuo , Kawai Yoshinobu , Itoh Satoshi
Published: November 2005

Density fluctuations in the frequency range of several MHz are observed in the turbulently heated TRIAM-1 tokamak plasma by means of a 4 mm microwave scattering method. It is found from measurements of the dispersion relation that this instability is considered to be the low-frequency ion acoustic instability.
Chemical and Physical Sputtering in F+ Ion Beam Etching of Si
Authors: Tachi Shin'ichi , Miyake Kiyoshi , Tokuyama Takashi
Published: November 2005

Silicon etching was performed by a mass-selected, low-energy, F+ ion beam in an ultrahigh vacuum and the amount of etched Si was measured by the “in situ” quartz crystal oscillator microbalance technique. Through this method, it was possible to derive separate chemical and physical sputtering yields for Si over the incident ion energy range of 100 eV∼3000 eV. The chemical sputtering yield was found to be larger than the physical one when the incident ion energy became less than 200 eV.
Direct Atomic Site Determination of Foreign Atoms in a Crystal Surface Layer by X-Ray Photoelectron Diffraction
Authors: Nihei Yoshimasa , Owari Masanori , Kudo Masahiro , Kamada Hitoshi
Published: November 2005

X-ray photoelectron diffraction (XPED) patterns for A12p, Ga3d and As3d from Ga1-x
Al
x
As (110) are measured. XPED patterns for Ga3d and As3d show characteristic differences due to the difference in atomic sites of Ga and As atoms in Ga1-x
Al
x
As crystal. On the other hand, the XPED pattern for A12p is almost identical to that for Ga3d. The results show a clear corresondence between XPED patterns and sites of photoelectron emitter atoms in the crystal. Based on the results, applicability of XPED measurements to direct atomic site determination of foreign atoms in a crystal surface layer is discussed.
Photoluminescence Associated with Nitrogen in Silicon
Authors: Tajima Michio , Masui Tsumoru , Abe Takao , Nozaki Tadashi
Published: November 2005

A new photoluminescence line at 1.1223±0.0001 eV has been observed for the first time in nitrogen-doped silicon crystals. This line never appears unless the crystal is intentionally doped with nitrogen. The relative intensity of the line increases with nitrogen concentration. These results show that the luminescence center responsible for the 1.1223-eV line is associated with nitrogen.
Structural Study on Amorphous-Microcrystalline Mixed-Phase Si:H Films
Authors: Matsuda Akihisa , Yoshida Toshihiko , Yamasaki Satoshi , Tanaka Kazunobu
Published: November 2005

Isochronal annealings have been done on the amorphous-microcrystalline mixed-phase Si:H, and its structure has been investigated through X-ray diffraction and ir absorption measurements. The number of microcrystals increases with an increase in annealing temperature up to 500°C, while crystallite size is kept unchanged. The crystallite size starts growing larger when the annealing temperature exceeds 550°C. On the basis of the results, a structural model has been presented for the mixed-phase Si:H films.
Rotation of the Electric Vector of the Polarized X-Rays by Diffraction in Crystals
Authors: Annaka Shoichi , Kohra Kazutake , Ando Masami
Published: November 2005

The electric vector ( E-vector) of linearly polarized X-rays rotates after diffraction in a crystal, because the diffraction amplitudes of the σ and π components are different. This rotation phenomenon is important in diffraction experiments using the polarized synchrotron radiation. This phenomenon has experimentally been studied for the Bragg case diffraction of the Bragg angle of 45° with the use of grooved perfect Ge crystals and Cu Kα radiation. Fine structures of the rotation of the E-vector have also been studied, which are due to the difference in the rocking curves for the σ and π states. Modified polarization factors are presented for some cases of the polarized incident X-ray beams.
Preparation of Perpendicular Magnetic Co-Cr Films by Vacuum Evaporation
Authors: Maeda Yasushi , Hirono Shigeru , Yoshii Shizuka
Published: November 2005

The vacuum evaporation technique has been applied to the preparation of perpendicular magnetic hcp Co-Cr films. It was necessary to suppress formation of the tetragonal phase in order to obtain films with high [0001] orientation perpendicular to the substrate.
New Type Hollow Cathode Discharge Tube with Continuously Variable Voltage
Authors: Iijima Tetsuo
Published: November 2005

New type hollow cathode discharge tube in which the operating voltage can be adjusted continuously without interchanging the electrode configulation and gas pressure is developed. Intensity ratio of the HeII to HeI lines emitting from this tube is increased with increasing the operating voltage. Moreover, in this type of discharge, the operating voltage is capable of increasing with axial magnetic fields.
Annealing of Self-Interstitials in Germanium
Authors: Fukuoka Noboru , Saito Haruo , Yoshida Hiroyuki
Published: November 2005

It has been reported that not all of the self-interstitials produced in germanium exchange position with impurity atoms, especially in crystals with low impurity concentration. The self-interstitials which did not perform the position exchange at room temperature were found to be annealed to lattice site at about 200°C with an activation energy of 1.4 eV. Another result reported here is that substitutional gallium atoms as a dopant do not perform position exchange with self-interstitials whereas other impurities do.
Counting of Cs Atoms by Selective Photoionization Method
Authors: Maeda Mitsuo , Nomiyama Yoshitsugu , Miyazoe Yasushi
Published: November 2005

A small number of individual Cs atoms was counted by means of two-step photoionization method with a pulsed dye laser. The number of the ion-electron pairs was counted by a secondary electron multiplier as a function of the number of atoms in the interaction which was calculated from vapor pressure data. Although there was a difference between them by a factor of five, detection less than one atom in the interacting region was demonstrated. One can expect to detect 10-3 atoms by this method, by increasing the repetition rate of the laser up to 100 pps.
Frequency Stabilization of a He-Xe Laser Using a Stark Spectrum in H2CO
Authors: Siio Itiro , Ohtsu Motoichi , Tako Toshiharu
Published: November 2005

The frequency of a 3.51 µm He-Xe laser has been stabilized without frequency modulation by means of the derivative signal of the Stark-modulated inverted Lamb dip in the ν5 transition of H2CO. We have obtained σ=1.2×10-14 as the square root of the Allan variance of the frequency fluctuation for an integration time of 25 s, showing comparable stability to that obtained using a conventional method.
A Distributed-Index Planar Micro-Lens Made of Plastics
Authors: Oikawa Masahiro , Iga Kenichi , Sanada Takeshi
Published: November 2005

A new distributed-index lens, a planar micro-lens, which can be monolithically fabricated on a planar substrate has been realized with optical plastics by means of a monomer exchange technique. A lower index plastic MMA (n=1.494) is diffused into a planar plastic substrate of DAI (n=1.570) with a higher index from around the circular disk mask of 3.6 mmφ. The spot diameter of focused light was as small as 27 µm with a focal length of 25 mm, and a clear image was observed by this lens.
Low Temperature Growth of Gallium Nitride
Authors: Gotoh Hideki , Suga Toru , Suzuki Hideo , Kimata Morihiko
Published: November 2005

High-quality single crystal GaN films have been obtained by RMBE method using the reaction of Ga with NH3. Then, the addition of ionized N2 with decreasing NH3 improved the electrical properties of GaN. Residual H2 decomposed from NH3 has been disturbing the GaN growth and promoting generation of nitrogen vacancies and the complexes.
Waveform Analysis of Acoustic-Emission
Authors: Iida Shoji
Published: November 2005

From an analysis of the initial signal of the acoustic-emission emitted from a solid material when it is fractured, a characteristic spectrum is obtained, which is considered to be dependent on the material. In order to explain this spectrum generation, the volumetric change of the fractured part, which provided the source of the acoustic-emission, was estimated.
Tunneling Characteristics of NbN/NbN Josephson Junctions with Glow-Discharge-Produced Amorphous Silicon Barriers
Authors: Shoji Akira , Shinoki Fujitoshi , Kosaka Shin , Hayakawa Hisao
Published: November 2005

The tunneling characteristics have been systematically measured for NbN/NbN Josephson tunnel junctions with glow-discharge-produced amorphous silicon layers as tunneling barriers. Junction quality parameters, the junction capacitance and the maximum Josephson current density have been obtained as a function of the thickness of the amorphous silicon layer. It is shown that a significant improvement in tunneling characteristics can be achieved by using an amorphous silicon barrier.
X-Ray Absorption Spectra of Uranium by Synchrotron Radiation
Authors: Adachi Hirohiko , Fujima Kazumi , Taniguchi Kazuo , Miyake Chie , Imoto Shosuke
Published: November 2005

The X-ray absorption spectra of U, UO2and UCl4near the U OIVand OVthresholds have been measured by use of synchrotron radiation. The absorption peaks at about 100 eV and 110 eV are observed for all of these materials. However, the detailed structure of the spectra depend on the chemical state.