bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of High-Coercivity Co–Pt Alloy Films by Target-Facing Type of High-Rate Sputtering
Authors: Naoe Masahiko , Hoshi Youichi , Yamanaka Shun'ichi , Kume Minoru
Published: November 2005

Co1-x
Pt
x
(0≦x≦0.2) thin films were prepared by using a Target-Facing type of high-rate sputtering (TFTS). The films deposited at lower argon gas pressure P
Ar(≦5 mTorr) have only a low coercive force H
c (<700 Oe). However, the value of H
c for films deposited at higher P
Ar (≧10 mTorr) increases monotonically as the Pt content increases, and films with high H
c (>1 kOe) can be obtained at a Pt content of above 11 at%. These films, whose crystallites are oriented randomly, also have a large inplane uniaxial magnetic anistropy constant K
1 (\cong2.5×106 erg/cc) and excellent hysteresis loop squareness (S\cong0.87, S
*\cong0.98).
Laser-Oscillating-Mode Dependence of Temperature Distributions in Laser Annealing of Semiconductors
Authors: Yamada Masayoshi , Ariyoshi Hiroshi , Yamamoto Keiichi , Abe Kenji
Published: November 2005

The temperature distributions produced by a moving cw circular or elliptical laser beam oscillating in various modes are calculated in a semi-infinite material. The normalized linear temperature is calculated to cover a wide range of experimental conditions. As an example, the actual temperature for silicon is presented, taking the temperature dependence of the thermal conductivity into account. It is found that the use of a TEM01 or mixed TEM01+TEM10 mode laser is very effective in obtaining a concave or flat-top temperature distribution in the beam.
The Effect of Repeated Operation on Electrochromism in an All-Solid-State Device Using Li-Doped MgF2 Thin-Film Electrolyte
Authors: Yoshimura Tetsuzo , Watanabe Masaki , Koike Yoshio , Kiyota Kohei , Tanaka Masao
Published: November 2005

We have fabricated a thin-film electrochromic device consisting of WO3 and Li-doped MgF2 films. Although the device exhibited excellent coloration and bleaching response (coloration period: ∼100 ms, bleaching period: ∼200 ms), the following changes in the device characteristics were observed upon retreated operation: 1) bleaching was impaired, 2) spontaneous coloration increased while spontaneous bleaching decreased and 3) the threshold voltage for coloration decreased. We have found that these changes can be attributed to the change in the free energy or the Li+ ion.
A Method to Determine Shape of Plasma Cross Section in a Non-Circular Tokamak
Authors: Ida Katsumi , Toyama Hiroshi
Published: November 2005

This paper describes a method for determining the shape of the plasma cross section shot-by-shot with a mini-computer. The magnetic surface is calculated from the magnetic field and flux, which are measured with 12 pairs of magnetic probes and 9 one-turn loops located in the shadow of the limiter. This method is so simple that the execution time is very short and even a mini-computer (LSI-11) can be used to perform the calculation in less than one minute. The control of plasma shape shot-by-shot is thus made possible by this method.
A Target System for p̄p and p̄d Total Cross-Section Measurement
Authors: Sumiyoshi Takayuki , Suzuki Shoji , Nakamura Kenzo
Published: November 2005

A target system with three Mylar target cells of diameter 10 cm was constructed for the precise and efficient measurement of p̄p and p̄d total cross-sections. Two of the target cells were filled with liquid hydrogen and liquid deuterium, and the remaining one was empty. Hydrogen gas was liquefied by a mechanical refrigerator and deuterium gas was liquefied by heat exchange with liquid hydrogen. The driving system of the vacuum jacket allowed any target cell to be brought into the beam within a few minutes, with good position reproducibility. Care was taken to minimize systematic errors caused by the target in determining the total cross-sections.
Long-Range Interaction in Multi-Layered Amorphous Film Structure
Authors: Ogino Toshio , Mizushima Yoshihiko
Published: November 2005

Long-range interactions in amorphous semiconductor have been studied by utilizing an amorphous As40Se60/Ge25Se75 multi-layered film in which the average composition is kept constant. The optical gap shifts to higher energies as the layer pitch decreases. After passing a peak, it finally approaches that of mixed ternary film. This is discussed in terms of a one-dimensional quantum size effect. The photostructural change is not affected by multi-layered structure. Infrared absorption peaks, due to As–Se3 and Ge–Se4 molecular vibrations, shift to higher wavenumbers as the layer pitch decreases. This phenomenon can be described by using the built-in electric field, or coulomb force between As–Se3 and Ge–Se4 clusters, due to the electronegativity difference between As and Ge atoms. This is supported lay the oscillator strength change with the change in layer pitch.
Starting Voltage of High-Pressure Sodium Lamps
Authors: Takahashi Kunihiko
Published: November 2005

Up to now there has been considerable variation in the starting voltage, V
s, of high-pressure sodium lamps, and some lamps do not light when the regular voltage is applied. In this paper, a method by which the value of V
s can be uniformly lowered is presented, together with an examination of the factors which influence V
s. By connecting a choke stability apparatus to the short support line, and by shortening the distrance between the ceramic arc tube and the long support line, it is possible to light a high-pressure sodium lamp with a high V
s value at a low voltage. Measurements of the electric potential distribution using the static electricity probe method indicated that the electric field intensity has a subtle effect on the starting voltage.
Dielectric Breakdown of Polyacetylene
Authors: Yoshino Katsumi , Terauchi Masaharu , Kim San Hyon , Hayashi Shigenori , Inuishi Yoshio
Published: November 2005

Cis-(CH)
x
, with lower electronic conductivity, has a higher breakdown strength than trans-(CH)
x
, with higher conductivity. However, the breakdown strengths of both (CH)
x
film isomers are much lower than those of other insulating polymers such as PE, PS, etc.
The breakdown strength of (CH)
x
increases with increasing temperature from 77 K to around room temperature, and then above some critical temperature T
c, it decreases rapidly. This behavior can be explained in terms of an electronic breakdown process at lower temperatures and by a thermal process at higher temperatures.
Many-Beam Calculation of Reflection High Energy Electron Diffraction (RHEED) Intensities by the Multi-Slice Method
Authors: Ichimiya Ayahiko
Published: November 2005

In order to calculate RHEED intensities by using the dynamic electron diffraction theory, crystals are sliced in thin stabs parallel to the surface. The crystal potential in each stab is taken as constant the normal to the surface. The RHEED intensities are calculated from the products of matrices obtained from Bethe's dynamic diffraction theory for each slab.
Layer Correlation in a-As2(SexS1-x)3 Systems
Authors: Mori Tatsuo , Yasuoka Hiroshi , Saegusa Hiroaki , Okawa Katsumi , Kato Michio , Arai Toshihiro , Fukunaga Toshiharu , Watanabe Noboru
Published: November 2005

The structure factors of a-As2(Se
x
S1-x
)3 (0≤x≤1.0) were measured by neutron diffraction, and the behaviors of the first sharp diffraction peaks with change in x were found to differ greatly from those of the other peaks. The positions of the first peaks did not shift with x. From these behaviors, we were able to confirm the presence of layer correlations in As-chalcogenide glasses. The bond lengths of As–S and As–Se do not change with alloying, and the bonding pairs of As and chalcogen atoms are combined randomly.
Electrical Conductivity and Photoconductivity in Polymethylpentene
Authors: Yun Mun Soo , Ozaki Masanori , Yoshino Katsumi , Inuishi Yoshio
Published: November 2005

Current-voltage characteristics and intrinsic photoconduction in polymethylpentene (PMP) for the wavelength range between 1100 and 1800 Å were studied. The current increases super-linearly with the applied voltage, which can be tentatively explained in terms of the Poole-Frenkel effect. The energy band gap evaluated from the photoconduction spectrum is about 8.6 eV which is comparable to that of polyethylene. From the polarity effect of the photoconduction, the predominant photocarrier is found to be positive carrier. At low temperatures the photoconduction under positive bias saturates at higher field but increases superlinearly at high temperatures, which is tentatively discussed by taking space charge effects into consideration.
Dependence of Superconducting Transition Temperature on Detection Techniques
Authors: Nara Koichi
Published: November 2005

The superconducting transition of indium is investigated to estimate the dependence of its transition temperature on the detection technique. The transition is detected by two techniques simultaneously using a common SQUID. The Meissner effect is directly detected by one technique, and the mutual inductance is detected by the other. The transition temperature determined by the former technique is found to be 0.3 mK higher than that determined by the latter. It is concluded that the detection technique must be specified in order to obtain superconducting fixed points with a reproducibility of 0.1 mK.
Preparation of Low Resistance Contact Electrode in Screen Printed CdS/CdTe Solar Cell
Authors: Kuribayashi Kiyoshi , Matsumoto Hitoshi , Uda Hiroshi , Komatsu Yasumasa , Nakano Akihiko , Ikegami Seiji
Published: November 2005

Heating conditions of carbon electrodes for CdTe and the effect of impurities in the carbon paste on the characteristics of solar cells are investigated. The series resistance (R
s) and the conversion efficiency (ηi) of solar cells exhibit strong dependence on O2 concentration in the heating atmosphere. Addition of Cu to the carbon paste causes R
s and diode factor (n) to decrease, resulting in a remarkable improvement in ηi. As a result of preparation of low resistance contact electrode for CdTe, a cell with 0.78 cm2 active area which was made from 50 ppm Cu-added carbon paste showed V
oc=0.754 V, I
sc=0.022 A, F
F=0.606 and ηi=12.8%.
Luminescence and Coloration in Sulfur-Doped NaCl and NaBr Crystals
Authors: Baba Mamoru , Kimura Norio , Ikeda Toshio
Published: November 2005

Luminescent emission and coloration due to the photochemical reaction arc induced by irradiation into the characteristic absorption bands of NaCl–S and NaBr-S crystals. As-grown crystals usually contain Na2S precipitates and show the characteristic luminescence due to Na2S crystallites. In freshly-quenched NaCl–S and NaBr–S crystals, excitation into the 4.15 eV absorption band due to the S--vacancy complex center does not show any coloration but causes the characteristic 2.0 eV emission. However, excitation by short-wavelength radiation around 5–6 eV produces coloration or luminescent emission depending on the temperature during irradiation. The coloration is due to the formation of the F center or the F center perturbed by the S- ion. The temperature dependence of the coloration is measured and is discussed for NaBr–S crystals.
Nucleation and Punch-Through of a Horizontal Bloch Line Detected in Dynamic Bubble Collapse
Authors: Iwatsuka Shinji , Iida Shuichi
Published: November 2005

The radial wall motion in an ion-implanted garnet film is investigated by using dynamic bubble collapse and chirality switching measurements. Experimental results at low drive fields are explained well in terms of the motion of a horizontal Bloch line (HBL). Chirality switching occurs during the punch-through of the HBL when ψ̄ reaches π. Two types of velocity peaks are detected in the dynamic bubble collapse experiments of x
+ bubbles. As compared with the results of the chirality switching measurements, these two peaks are considered to correspond to the nucleation and the punch-through of a HBL, respectively.
Accurate Measurements of the Wavelengths and Material Constants of 1.5 µm InGaAsP/InP Lasers
Authors: Ohtsu Motoichi , Tagawa Haruo , Kotani Hiroki
Published: November 2005

The wavelengths of single longitudinal-mode 1.5 µn InGaAsP/InP lasers were measured at room temperature to an accuracy of 0.9 pm. An accurate wavementer was constructed for this purpose, and it exhibited an accuracy as high as 0.35 pm. The wavelength shifts of the lasers under unit changes in the injection current I and temperature T were derived from the results. By using the values of these wavelength shifts, the value of the temperature coefficient β of the refractive index in the cavity, and that of the thermal resistance R

T
were accurately estimated. The results of these non-destructive measurements are as follows:
(Laser No. 1) 1.03 × 10-4 K-1≦β≦1.07 × 10-4 K-1 and 79.8 K/W≦R

T
≦98.1 K/W (for 290 K≦T≦295 K and 86 mA≦I≦96 mA).
(Laser No. 2) 0.81 × 10-4 K-1≦β≦0.83 ×10-4 K-1 and 133 K/W≦R

T
≦136 K/W (for 291 K≦T≦295 K and 70 mA≦I≦80 mA).
An Analysis of Various Properties of Surface Discharge Using a Transmission-Line Model
Authors: Kanematsu Atsushi , Sawa Goro , Ieda Masayuki
Published: November 2005

A transmission-line model for surface discharge and the analytical solution of the model have been presented previously. In this paper, an attempt is made to interpret the various properties of surface discharge with this model. The properties discussed are the discharge starting voltage vs the specific capacitance; the propagation length vs the voltage application time; the applied voltage vs the advancing length; and the charge quantity vs the advancing length. It is shown that the analytical relations can explain the qualitative features of published experimental data comparatively well. Because of the lack of fully systematic measurements as well as assumptions contained in the model, however, a detailed quantitative comparison has been left for solution in the future.
Effective Application of Turbulent Heating to High Density Tokamak Plasma
Authors: Watanabe Takechiyo , Nagao Akihiro , Nakamura Yukio , Itoh Satoshi
Published: November 2005

The applicability of turbulent heating to stable high density tokamak plasmas, which are produced by gas-puffing, is experimentally investigated. Up to the line-average electron densityn̄e≈1×1014cm-3the low frequency ion acoustic instability is identified by the application of a relatively small value of pulsed current allowing for the effective ion heating to be confirmed. Calculations of onset conditions for the ion acoustic instability show that the plasma cooling in the outer region by gas-puffing and electron Ohmic heating by pulsed current are advantageous in the excitation of current-driven ion acoustic instability.
Measurement of Minority-Carrier Diffusion Coefficient in Silicon by AC Photo-Current Method
Authors: Morohashi Makoto , Sawaki Nobuhiko , Somatani Toshifumi , Akasaki Isamu
Published: November 2005

The ac photo-current method was studied and improved theoretically as a method of determining the diffusion coefficient and lifetime mapping of a semiconductor wafer. It was found that if the diffusion length of excess carriers is greater than the junction depth of a p-n diode structure, the phase shift of the ac photo-current due to short-wavelength light is independent of the lifetime and is determined by the diffusion coefficient. If the diffusion length is shorter than the junction depth, on the other hand, the phase shift is influenced by the lifetime as well as by the diffusion coefficient. The results were used to measure the diffusion coefficient of holes in n-Si.
High Electron Mobility in p-Type III-V Compound Semiconductors
Authors: Otsuka Eizo
Published: November 2005

Electron scattering by impurities in degenerate semiconductors is calculated by a simplified square well-or-hump potential model. For various III-V compound semiconductors with large hole-to-electron mass ratios m
h/m
e, it is found that the scattering cross-section by a screened acceptor is much smaller than that by a screened donor. The donor-to-acceptor ratio of the cross-sections σD/σA amounts to 550 in InSb at a carrier density of 1018 cm-3. A simple relation σD/σ
A
∝(m
h/m
e)2 exists over the available III-V compounds. The absolute magnitude of the cross-section is also discussed in conjunction with the pseudo-neutral impurity scattering model.
Sausage Instabilities Stabilized by Radial Motion in Z-Discharged Plasma Channel for Beam Propagation in LIB-Fusion
Authors: Murakami Hiroyuki , Kawata Shigeo , Niu Keishiro
Published: November 2005

The stability of current-carrying plasma channels, which have been proposed for transporting intense ion beams from the diodes to the target in LIB-fusion devices, is discussed. The growth rate of the most dangerous surface mode, that is, the axisymmetric sausage instabilities, are examined for plasma channels with or without radial fluid motion. The growth rate of the channel with radial fluid motion is shown to be far smaller than that of the channel with no fluid motion. It is concluded that a stable plasma channel can be formed by radial fluid motion.
Study of Transformations among α, γ and γ' Forms in Nylon 12 by X-Ray and DSC
Authors: Hiramatsu Nobuyasu , Haraguchi Kazunao , Hirakawa Susumu
Published: November 2005

The transformation behaviors of nylon 12 were investigated using wide-angle X-ray diffraction (WAXD), X-ray fiber patterns and differential scanning calorimetry. The γ' form could be distinguished from the γ form in spite of their very similar WAXD patterns, because the γ form cannot be transformed into the α form, while the γ form can be so transformed under high pressure. The γ' to γ transformation occurs on annealing above 110°C at atmospheric pressure. The γ to γ' and α to γ' transformations occur on drawing at atmospheric pressure above 50°C and above 70°C, respectively. The transformation behaviors presented in this paper and in a previous paper [N. Hiramatsu, S. Hashida and S. Hirakawa: Jpn. J. Appl. Phys. 21 (1982) 651] are summarized.
Computer-Controlled Domain Detector
Authors: Pfützner Helmut , Schwarz Gerhard , Fidler Josef
Published: November 2005

This paper is considered a first approach to detecting the domain configuration of coated Si–Fe sheets by computer-controlled field scanning. A topogram of the domains is plotted, and the physical origin of the detected field components is discussed. Also, stray field topograms of magnetized sheets are presented. These indicate that the field intensity cannot be associated with the angle of misorientation of an individual grain.
Change of Energy-Level Distribution of Photoemission Sources in Al and Zn Caused by Scratching
Authors: Shigekawa Hidemi , Iwatsu Reima , Okada Masamichi , Hyodo Shin-ichi
Published: November 2005

Photoemission from Al (99.99% purity) specimens was measured for the photostimulation wavelength ranging from 190 to 700 nm. The specimens were scratched with a steel needle at temperatures from 77 to 290 K and at pressures from 10-5to 10-7Torr. Whereas prior to scratching the emission peaks from Al specimens appeared in a range from 250 to 290 nm, they shifted to a 290–350 nm range after scratching. Although this result is nothing but a manifestation of the so-called exoelectron emission, it has not been well recognized that scratching causes a change in the number of photoemission sources at various energy levels. The wavelength at the peak emission was influenced neither by the specimen temperature nor by the degree of vacuum. Similar results have been obtained for Zn specimens, though the yield observed was two orders of magnitude lower than that for Al.
Low Temperature Reactions at Si-Metal Contacts –From SiO2 Growth due to Si–Au Reaction to the Mechanism of Silicide Formation
Authors: Hiraki Akio
Published: November 2005

When Si is in contact with metal film, it readily reacts at low temperatures (≤200°C) leading to several interesting effects. For example, thick (∼1000 Å) SiO2 growth for a short time (∼10 min) due to Si–Au reaction and uniform silicide layer formations at Si/Pd, Pt, Ni interfaces.
Since Si is a typical covalent semiconductor with high melting point (∼1400°C), without the presence of such effect of metal to weaken the covalent bond of Si adjacent to the metal, the above reactions rarely occur. As a possible mechanism of the bond-weakening, the present author proposes a model postulating electronic screening of Coulomb interaction responsible for the covalent bonding due to mobile free electrons in the metal films. This “Screening model” seems to be evidenced through observations of initial stages of Si-Au and -Pd reaction by both electron and ion scattering spectroscopies.
In addition, new usage of the channeling effect of MeV He+ ions is demonstrated to be a powerful tool for interface and surface studies.
Helical Pitches and Tilt Angles in Room Temperature Ferroelectric Chiral Smectic C Liquid Crystals, MORA n and MBRA n
Authors: Skarp Kent , Flatischler Kurt , Kondo Katsumi , Sato Yuzuru , Miyasato Keita , Takezoe Hideo , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

The helical pitches and the tilt angles are measured as a function of temperature for recently synthesized room temperature ferroelectric Sm C* liquid crystals to examine the possibility as materials for switching devices. The pitch of MBRA 8 is almost independent of temperature except in the range close to the Sm A to Sm C* phase transition, where it appears to decrease steeply as in nOBAMBC. In MORA 8 and 12, it gradually increases with temperature but does not decrease near the transition from Sm C* to isotropic. The tilt angle of MBRA 8 is relatively small as compared with the desired value of 22.5° for the best contrast. The tilt angle of MORA n could not be determined because the spontaneous polarization is too small to unwind the helix for the measurements. The present substances are not suitable for switching devices by themselves, but are pointed out to be useful as mixing components.
Effects of Transition Metal Additives on Electronic Properties in Amorphous GeSeTe Films
Authors: Watanabe Ichiro , Noguchi Shigeru , Shimizu Tatsuo
Published: November 2005

A large electrical conductivity increase has been observed when a small amount of Ni or a considerably larger amount of Mn is added in Ge100/3Se100/3Te100/3 films prepared by thermal evaporation. From measurements of the temperature dependences of the electrical conductivity and thermoelectric power, and of optical absorption, we were able to conclude the following. Neither Ni nor Mn bring about a large shift of the Fermi level. The increase of the electrical conductivity results from the appearance of the variable range hopping conduction through Ni sites in the case of Ni, while it is a result of the decrease of the mobility gap in the case of a large amount of Mn.
Properties of Passivation Film on Silicon due to HF–NO2 Mixed Gas Reaction
Authors: Ito Hideo , Ono Kazumasa
Published: November 2005

The properties and formation mechanism of a surface passivation film on silicon are discussed. The film is produced by a staining reaction in a mixed HF–NO2 gas, followed by a subsequent low temperature oxidation. It is found that the stain film formation reaction is accompanied by the surface etching reaction. From experiments by varying the composition of the mixed gas and conditions of the treatment, it is found that particularly NO2 gas component has an important bearing on the film forming and etching reactions. These reactions are independent of the conductivity type or the specific resistivity of the silicon. The present surface passivating film results in surface stabilization of silicon devices by having high breakdown voltage.
Lamellar and Grain Boundary Models for the Electrical Properties of Post-Oxidized ITO Films
Authors: Mizuhashi Mamoru
Published: November 2005

A very distinctive feature of the resistivity change during the course of heat treatment in air and a rather weak dependence on the impurity concentration are described on the basis of the diffusion of oxygen and the formation of highly resistive grain boundary.
Photoluminescence and Electrical Properties of Undoped and Cl-Doped ZnSe
Authors: Satoh Shiro , Igaki Kenzo
Published: November 2005

Undoped and Cl-doped ZnSe specimens were heat-treated in Zn or Se vapor, or in molten Zn, and the photoluminescence spectra and electron concentration of the specimens were measured. Several new emissions were observed in high-purity ZnSe with Cl concentration ([Cl]) lower than 1015 cm-3 while SA-emission band and a IDEEP
1 line were observed in ZnSe with [Cl]>1015 cm-3 heat-treated in molten Zn. The former was observed to increase with [Cl] and with the Zn vapor pressure, and the latter to increase with [Cl]. The electron concentration at room temperature was proportional to [Cl] for [Cl]<1017 cm-3. This paper proposes a model explaining these effects on the [Cl] dependence of the concentration of defects, ClSe donors, SA-centers (V
ZnClSe) and V
-
Zn.
Effect of Prestressing on the ns Range Electrical Breakdown in Polymeric Insulating Films
Authors: Kitani Isamu , Arii Kiyomitsu
Published: November 2005

The electrical impulse breakdown of prestressed polymer films was investigated in the ns range. The effect of prestressing on the breakdown was observed in polyethylene terephthalate (PET) and polycarbonate (PC), but not in polystyrene (PS) or polypropylene (PP). The amount of space charge estimated from the transient currents was large enough to induce electric field distortion in the bulk for all specimens. The effect in PET and PC is attributed to field distortion due to space charge accumulation near the electrodes, which can be estimated as electrons at the cathode and holes at the anode. The reason why the effect was not observed in PP and PS can be explained as the result of their own high breakdown strength in strong non-uniform fields.
A Waveform Reproduction Study of Time-Domain Reflectometry. II. Quick Determination of Dielectric Relaxation Time
Authors: Hayashi Shigeo , Aihara Ariyuki
Published: November 2005

The systematics of second-order reflections in dielectric time-domain reflectometry are studied with emphasis on the relation between the dielectric relaxation time and the waveform characteristics (fall time and appearance time). A procedure is presented for determining the relaxation time from the characteristics, and has been successfully applied to several Debye-type dielectric substances, whose relaxation times span the range 3–150 ps, the lower of these two times being shorter than the rise time of the incident step voltage from the step generator.
Enhancement of Gas Sensitivity by Controlling Microstructure of α–Fe2O3 Ceramics
Authors: Nakatani Yoshihiko , Sakai Masayuki , Matsuoka Michio
Published: November 2005

We have found that the gas sensitivity of α–Fe2O3 ceramics can be greatly enhanced by controlling its microstructure by adding quadrivalent Ti, Zr or Sn. These metals have the effect on suppressing the grain growth and crystallization, and consequently increasing the specific surface area of the sensing element. With Sn in particular, the sensing element consists of ultra-fine grains as small as about 100 Å and has an extremely large specific surface area of 125 m2/g. However, the additives are effective only in the presence of the sulfate ion, which is considered to localize mainly on the surface of the α–Fe2O3 grains. Thus the surface of the grains, which is fairly amorphous, is thought to play an essential role in the gas sensitive mechanism.
Helical Field of JIPP T-II Apparatus
Authors: Sometani Taro , Tanahashi Shugo
Published: November 2005

The measured toroidal helical field of the JIPP T-II apparatus does not vanish on the geometrical axis of the helical winding, contrary to the prediction of the usual theory. The result of measurement can be explained only by an improved theory. On account of the nonvanishing part of the helical field, the magnetic axis of JIPP T-II should be nonplanar and should be shifted on the average inwards with respect to the geometrical axis.
X-Ray Geometrical Smoothing Effect in Indirect X-Ray-Drive Implosion
Authors: Mochizuki Takayasu , Sakabe Shuji , Yamanaka Chiyoe
Published: November 2005

X-ray geometrical smoothing effect in indirect X-ray drive pellet implosion for inertial confinement fusion has been numerically analyzed. Attainable X-ray driven ablation pressure has been found to be coupled with X-ray irradiation uniformity.
Magnetic Domain Structures in CoCr Films Studied by Lorentz Microscopy
Authors: Ohkoshi Masatoshi , Kusuda Tetsuzo
Published: November 2005

Magnetization distribution and behavior of magnetization in CoCr sputtered films of various thickness are studied by high-resolution Lorentz microscopy. The perpendicular component of magnetization increases with increasing film thickness, corresponding to the increase in the Q-value. The dominant mechanism of magnetization reversal changes from the domain wall displacement mode in the 200 Å thick film to the rotational mode in the 1000 Å thick film. In the 600 Å thick film, elongated domains with a kind of cross-tie walls are formed perpendicular to an AC demagnetizing field in the film plane.
Behaviours of Thermally Induced Microdefects in Heavily Doped Silicon Wafers
Authors: Tsuya Hideki , Kondo Yojiro , Kanamori Masaru
Published: November 2005

Thermally induced microdefects in heavily doped silicon wafers are investigated. It has been shown that the generation of thermally induced microdefects is strongly affected by the type and concentration of dopants, and that microdefects necessary for intrinsic gettering are not easily generated in heavily doped n-type wafers. To generate the microdefects in heavily doped n-type wafers, an improved heat treatment procedure is developed. The observed results are discussed in terms of the difference of point defect density between p- and n-type wafers.
Low Temperature Chemical Vapor Deposition Method Utilizing an Electron Cyclotron Resonance Plasma
Authors: Matsuo Seitaro , Kiuchi Mikiho
Published: November 2005

The plasma deposition apparatus developed in this study can realize a deposition of dense and high quality thin films, such as Si3N4 and SiO2, without the need for substrate heating. It does this by enhancing the plasma excitation efficiency at low gas pressures (10-4 Torr) and by the acceleration effect of ions with moderate energies (10 to 20 eV), using a microwave ECR (Electron Cyclotron Resonance) excited plasma, and a plasma stream extraction onto the specimen table by a divergent magnetic field method. The Si3N4 and SiO2 films deposited are comparable to those prepared by high temperature CVD and thermal oxidation, respectively, in evaluations such as by buffered HF solution etch rate measurement.
A Dual-Stripe Phase-Locked Diode Laser
Authors: Ohsawa Jun , Ikeda Kenji , Takahashi Kazuhisa , Susaki Wataru
Published: November 2005

An AlGaAs dual-stripe laser, where each stripe has an SBH configuration, has been fabricated by means of chemical etching followed by liquid phase epitaxy. Phase-locked oscillation is observed under pulsed and CW operations. This is confirmed by the coalescence of the two longitudinal modes, as well as by the interference fringe measured in the far-field radiation pattern.
Measurements of Ablation Pressure and Mass Ablation Rate Using a Target Pendulum and a Thin Foil Target at 10 µm Laser Wavelength
Authors: Daido Hiroyuki , Tateyama Ryuzi , Ogura Kazuki , Mima Kunioki , Nakai Sadao , Yamanaka Chiyoe
Published: November 2005

The ablation pressure and the mass ablation rate for a 10 µm CO2 laser were measured using two methods: a ballistic target pendulum and shifted X-ray emission images which are equivalent to X-ray back-lighting. The measured ablation pressure was 10 Mbar and the mass ablation rate was 106 g/cm2·sec at the absorbed laser intensity of 5×1013 W/cm2. Comparing the ablation mass rate measured by the pendulum with that derived from the penetration depth of the hot electrons using Kα line emission, we could identify the hot electron driven ablation as the dominant process.
Orientation Dependence of the Quadrupole Relaxation in NaNO2
Authors: Kanashiro Tatsuo , Ohno Takashi , Satoh Mitsuo
Published: November 2005

The ratio of the quadrupole relaxation probability,W2for |Δm|=2 transition toW1for |Δm|=1 transition has been measured at 132K at23Na site in NaNO2by the method of acoustic nuclear magnetic resonance. The orientation dependence ofW1andW2is calculated in terms of the fourth rankM-tensor components using a point charge model. The calculation based on the assumption that the mode of lattice vibrations is completely isotropic shows the opposite tendency to that of the experimental results. Anisotropy of the lattice vibrations and/or other charge distributions of NO-2ion should be taken into account.
Photoconductive and Bolometric Effects in Trans-Polyacetylene by Near Infrared Light Irradiation
Authors: Miura Muneyuki , Kamagami Shin-ichi , Takezoe Hideo , Fukuda Atsuo , Kuze Eiichi , Shirakawa Hideki , Ikeda Sakuji
Published: November 2005

Photoinduced current has been measured in the range 0.5–3.4 eV in trans-polyacetylene of about 100 µm thickness. The typical photoinduced current spectrum shows a peak at 1.4 eV below the interband absorption edge and a sharp decrease below 0.7 eV. By observing the dependence of photoinduced current spectra on sample degradation and compensation with ammonia, it has been concluded that there exist four distinct spectral regions. Photoinduced current in one of them, the lowest energy region, has been ascribed to the bolometric effects, while those in the other regions are genuine photoconductivity.
The Influence of Dislocation Density on the Uniformity of Electrical Properties of Si Implanted, Semi-Insulating LEC-GaAs
Authors: Honda Takashi , Ishii Yasunobu , Miyazawa Shintaro , Yamazaki Hajime , Nanishi Yasushi
Published: November 2005

The electrical homogeneity of the Si implanted layer in LEC-grown, semi-insulating GaAs was investigated by Hall measurements. Variations in electrical properties across the substrate were compared with dislocation density distribution.
An M-shaped sheet resistance and a W-shape sheet carrier concentration variation across the substrate were closely correlated with a W-shaped dislocation density distribution. Almost uniform electrical properties, except for the wafer periphery, were verified for the substrate having a U-shaped dislocation density distribution.
Sausage Instability in a Proton-Beam Transport through Wall-Confined Plasma Channel
Authors: Yamada Tetsuo , Masugata Katsumi , Matsui Masao , Yatsui Kiyoshi
Published: November 2005

An instability observed previously in a 800-keV of proton-beam transport through a wall-confined, z-discharged plasma channel (l-m long) has been identified as a sausage type from measurements made using an image converter campera. Clear evidence of the sausage instability has been obtained from the streak and framing photographs. When the instability grows with time, the wavelength tends to increase. The pinch velocity of the channel has also been measured in a parameter space, which gives reasonable agreement with the existing theory.
Pyroelectricity in Polytrifluoroethylene
Authors: Oka Yoshio , Koizumi Naokazu
Published: November 2005

Pyroelectricity has been observed in polytrifluoroethylene, which was strongly enhanced in the sample subjected to rapid quenching from the melt. The pyroelectric coefficient showed anomalous behavior of changing signs twice over the temperature range of 100 to 330 K. On this point, the nature of the pyroelectricity in polytrifluoroethylene was greatly different from that in other pyroelectric fluorocarbon polymers. It was suggested from the temperature dependence of the pyroelectric coefficient that the origin of the pyroelectricity was the dipole motions in the amorphous region.
Measurement of the Temperature Fluctuation in a Resistor Generating 1/f Fluctuation
Authors: Hashiguchi Sumihisa
Published: November 2005

A new method is devised to measure the temperature fluctuation in a current-carrying resistor. The spectrum of the temperature fluctuation is determined from the values of the resistance fluctuation, the variance fluctuation, and their product. It is found to be proportional to f1.1 and the temperature fluctuation amounts to 0.13 K2 in the frequency range of 104–102 Hz. This agress well with the calculated value of the equilibrium temperature fluctuation in the effective volume generating 1/f noise.
Optical Bistability in a Semiconductor Laser Amplifier
Authors: Nakai Tetsuya , Ogasawara Nagaatsu , Ito Ryoichi
Published: November 2005

Optical bistability has been observed in a semiconductor laser operating as an amplifier. The bistability arises from the refractive index change due to a decrease in the active-region carrier density accompanied by optical amplification. Output pulsations due to the competition between the free-carrier and thermal effects have also been observed.
Silicone-Resin-Clad Germanium-Oxide Glass Optical Fiber
Authors: Takahashi Hiroshi , Sugimoto Iwane
Published: November 2005

Silicone-resin-clad germanium-oxide (germanate) glass optical fiber has been prepared. A minimum loss value of 13 dB/km at 1.1 µm has been obtained by decreasing the scattering loss caused by imperfection of fiber structure at core-cladding boundary.
γ-Ray Radiation-Induced Changes in Switching Current of Polyvinylidene Fluoride
Authors: Takase Yoshihiko , Odajima Akira
Published: November 2005

Transient current measurement of stretched PVDF film revealed that γ-ray irradiation induced retardation in the switching behavior. The change in the transient current appeared most prominently in its hump region. The radiation induced retardation was far more obstinate than the aging induced one. The activation field and energy for the film irradiated with 10 Mrad were 1.31 GV/m and 0.551 eV, a little larger than the 1.15 GV/m and 0.542 eV for the unirradiated one. Retardation was attributed to the decrease in the growth rate of domain and the nucleation probability.
Formation of p+-layer in GaAs by dual implantation of Zn and As
Authors: Kasahara Jiro , Taira Kenichi , Kato Yoji , Arai Michio , Watanabe Naozo
Published: November 2005

Dual implantation of Zn and As in GaAs resulted in a p
+-layer superior to that formed by the implantation of Zn only. Dual implantation improved the electrical activity of Zn significantly. The double-peak often observed in the hole concentration profile of the sample by the implantation of Zn only was eliminated by equal dose co-implantation of As, in which the hole concentration profile was Gaussian-like with a peak at the projected range (R
p
) of Zn. The equal dose co-implantation of As also resulted in lower sheet resistance, suggesting that stoichiometry in the implanted layer is essential for activating implanted impurities in GaAs effectively.
CW Ar+ Laser Pumped by an Intense Electron Beam
Authors: Hara Tamio , Sadamoto Yoshiro , Hamagaki Manabu , Ohgo Tadashi , Dote Toshihiko
Published: November 2005

Continuous-wave laser oscillation has been obtained on the 488.0 nm transition of singly ionized argon in a pure Ar plasma excited by a steady intense electron beam, of which energy and current can be independently controlled up to 300 eV and 11 A, respectively. This scheme has possibilities of increasing the efficiency, power and spectral range of ion lasers.
Carrier Depletion in Sulfur Doped Epitaxial GaAs Layer by Boron Ion Implantation
Authors: Itoh Tadatsugu , Nomura Masahiro
Published: November 2005

The carrier depletion by boron ion implantation in sulfur doped epitaxial GaAs layers has been investigated. Diffusion coefficient of boron in GaAs is vather small and the carrier depleted region in a sulfur doped epi-layer formed by boron ion implantation remains stable after a thermal treatment at 800°C for 20 min by the powder annealing method. The implanted boron atoms deplete carriers in the sulfur doped layer, and concentration profiles of calculated residual carriers using the empirical formula which we have proposed in this paper agree well with experimental results.
A New Crystallographic Shear Structure in Tin Oxide
Authors: Kaito Chihiro , Harada Toshio , Miyano Toshio
Published: November 2005

Tin oxide crystals grown by electron beam irradiation of vacuum deposited amorphous films were investigated by a high resolution transmission electron microscopy (HRTEM) with the aid of computer simulation. A new type of ordered (110) CS structure with 1/2 [110] shear and 1/2[11̄0] glide were found in the reduced Snm+1Om crystals with m=4.
Fluorescence and its Nd3+ Concentration Dependence of Nd-Doped SiO2 Glasses Prepared by Plasma Torch CVD
Authors: Arai Kazuo , Namikawa Hiroshi , Kumata Ken , Ishii Yoshiro , Tanaka Hiroaki , Iida Ichio
Published: November 2005

The time resolved fluorescence spectra and their Nd3+ concentration CNd dependence were observed in Nd-doped SiO2 glasses prepared by plasma torch CVD. The 4F3/2 radiative emissions observed consist of a fast (FDC, τm≃0.35 µs) and a slow (SDC, τm≃470 µs) decay component. The FDC are characterized by the intensity ratio (4F3/2–4I11/2/4F3/2–4I9/2>1), but the SDC by the inverse ratio and the spectral shift to the longer wavelength. The SDC increases and reaches almost constant values in higher CNd. The FDC can not be observed in very low CNd region, but increases abraptly in higher CNd. The FDC is ascribed to the Nd3+ in the clustering microstructure and the SDC is ascribed to the isolated Nd3+ in crystal field unique to unitary SiO2 glass.
A New Method of Grating Spectroscopy
Authors: Yoshihara Kunio , Kitade Atsuo , Tazawa Masato
Published: November 2005

A new spectroscopic method is described which enables a radiation spectrum to be reconstructed by simultaneously measuring the intensity distribution of the Fraunhofer diffraction pattern produced by a single slit or a number of slits without speparating different and overlapping orders. Computer experiments have verified the validity of the method, although ideal resolution has not yet been achieved.
Characteristics of Electro-Optic Device Using Conducting Polymers, Polythiophene and Polypyrrole Films
Authors: Kaneto Keiichi , Yoshino Katsumi , Inuishi Yoshio
Published: November 2005

Detailed characteristics of electro-optic elements (color switching and memory) utilizing the spectral change of conducting polymers by electrochemical doping and undoping are studied. The response time of color switching, for example, red↔blue in polythiophene film in the electrolyte of LiBF4/acetonitrile is 30∼100 msec under the applied voltages of -2.0↔+4.0 V vs. Li plate. More than 103 cycles of color switch are observed quite reproducibly. Three color states of yellow green, dark brown and blue are demonstrated for polypyrrole film.
Fabrication of A15 Nb3Al Josephson Tunnel Junction using CF4 Cleaning Process
Authors: Katoh Yujiro , Tanabe Keiichi , Michikami Osamu
Published: November 2005

A15 Nb3Al thin-film Josephson tunnel junctions having an oxide barrier and a Pb counterelectrode have been fabricated by photolithography. Nb3Al junction characteristics have been found to be drastically influenced by pre-cleaning conditions. Excellent junction qualities with low leakage current were achieved by adopting RF sputter-etching in Ar+CF4 plasma as a pre-cleaning technique, instead of conventional Ar plasma. The chemical reaction of CF4 radicals has been found to provide great utility for obtaining high quality tunnel junctions of an A15 Nb3Al compound with a very short coherence length.
Photoluminescence and Lattice Mismatch in InGaAs/InP
Authors: Yagi Tetsuya , Fujiwara Yasufumi , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

A new photoluminescence (PL) band in LPE InGaAs layers nearly lattice-matched to InP has been observed at 0.69 eV at 77 K. This PL band has a strong correlation with the degree of the lattice mismatch between InGaAs and InP, and the intensity shows the minimum at the lattice mismatch of -0.08∼-0.07%. The in-depth profile of the PL intensity has been also measured, the result showing that the intensity slightly increases in the interface region of InGaAs and InP, though the PL intensity of the InGaAs edge emission is nearly constant in the InGaAs layer. These results are well explained by considering the difference of the lattice parameters of InGaAs and InP at both the LPE growth and room temperature, and might suggest the existence of some defects introduced during the epitaxial growth by the lattice mismatch between InGaAs and InP.
Optical Absorption Characteristics of GaAs–AlGaAs Multi-Quantum-Well Heterostructure Waveguides
Authors: Tarucha Seigo , Horikoshi Yoshiji , Okamoto Hiroshi
Published: November 2005

Optical waveguide absorption characteristics of MBE grown GaAs–AlGaAs MQW doubleheterostructure wafers are studied by measuring edge luminescence under photoexcitation, and are compared with those of conventional GaAs DH wafers. The edge luminescence spectra show a double peak structure which is well explained by waveguide self-absorption, rather than by L0-phonon participation as has been suggested by other workers. The optical absorption loss of the unexcited MQW waveguide at its lasing wavelength is found to be much smaller than that for the conventional DH waveguide.
Achievements of the Quantum Noise Limited Frequency Stability in AlGaAs Semiconductor Laser
Authors: Tsuchida Hidemi , Tako Toshiharu
Published: November 2005

The frequency of an AlGaAs semiconductor laser has been locked to a stable Fabry-Perot interferometer by controlling the injection current. In the integration time range of τ\gtrsim10-4, the resulting frequency stability was in good agreement with the theoretical stability which was estimated taking into account the quantum phase fluctuations of the laser.
Solar Cells Obtained by Incoherent Light Annealing of Phosphorus Implanted Silicon
Authors: Correra L. , Pasini A. , Morettini L. , Pedulli L.
Published: November 2005

Solar cells have been obtained after solid phase regrowth of phosphorus implanted silicon induced by an incoherent light source. Their characteristics are compared with those of identically implanted cells obtained by electron beam and furnace annealing. The main results are: a) the carrier concentration and the mobility profiles are the same of those obtained by electron beam annealing; b) I-V characteristic, quantum efficiency, fill factor and efficiency of the cells annealed by incoherent light are similar to those obtained by the other annealing techniques.
GaAs Molecular Beam Epitaxy on Be Implanted GaAs Layers
Authors: Takamori Akira , Miyauchi Eizo , Arimoto Hiroshi , Bamba Yasuo , Hashimoto Hisao
Published: November 2005

GaAs layers have been grown by molecular beam epitaxy (MBE) on Be implanted GaAs layers using maskless ion implantation. Low-temperature (4.2 K) photoluminescence (PL) of the Be implanted layers and successively grown MBE layers on the implanted layer without post-anneal of implanted damages, has been measured. PL intensity of bound exiton from the implanted layers with dose of 1×1012-1×1013 ions cm-2 at 160 keV decreased considerably compared with the unimplanted layers. However, PL intensity measurement has shown that a high quality GaAs could be grown on top of the implanted layer by MBE at 600°C without post-implantation anneal.
Formation of Very Thin Anodic Oxide of InSb
Authors: Fujisada Hiroyuki , Nakagawa Tadashi , Sasase Takafumi
Published: November 2005

An anodic oxide of InSb has been formed under a constant voltage to control thickness. It is found that the anodic oxide can be voltage-controlled up to 350 Å with a very good optical flatness and up to 500 Å if a small roughness is allowed. The surface roughness of the oxide increases drastically with increasing thickness. The transport number of oxygen ions in the oxide during anodization may be assumed to be 1 at least up to 750 Å.