bluuebunny/crossref_metadata_2025 huggingface dataset:
Ferrite-Plating in Aqueous Solution: A New Method for Preparing Magnetic Thin Film
Authors: Abe Masanori , Tamaura Yutaka
Published: November 2005

We describe the principle and performance of the new method. It facilitates formattion of crystalline-spinel films at low temperature (<80°C) for various compositions, and on substrates of not only metal but also oxide and organic compounds. Hydrolyzed metal ions in an aqueous solution (pH=6∼11, T=40∼80°C) are incorporated into the spinel film on the substrate associated with air oxidation or anodic oxidation of ferrous ion. We have plated Fe3O4 and CoFe2O4 films on substrate of Cu, PET and stainless steel. They are polycrystalline with no preferred orientation, exhibiting no magnetic anisotropy. Polar Kerr rotation of these films has been measured.
Resistance Anomaly of Nb–Si Thin Films
Authors: Ōgushi Tetsuya , Obara Kozo , Anayama Takeshi
Published: November 2005

A resistance anomaly of very thin Nb–Si films is reported. The anomaly is characterized by a sudden drop in the resistance by a factor of ∼103at a temperature (TD) of ∼180Kwithout any application of pressure. The lower resistance-state (∼zero Ω) is constant to 4.2Kso far as we measured.TDdepends on measuring current and on magnetic fields. The anomaly has properties very similar to those of CuCl under high pressure.
Microwave Absorption Lines of 18O2 in its Electronic Ground State (X3Σ-
g)
Authors: Endo Yasuki , Mizushima Masataka
Published: November 2005

Microwave absorption lines of 18O2, in υ=0 and υ=1 states, are observed in the 119 and 60 GHz regions. Precisely determined molecular parameters for the 18O2 species are compared with those of 16O2 previously determined, and isotope dependences of the parameters are briefly discussed.
Reduction of Impurities in Fluoride Glass Optical Fiber
Authors: Mitachi Seiko , Terunuma Yukio , Ohishi Yasutake , Takahashi Shiro
Published: November 2005

A sublimation purification technique was developed for fluoride fiber materials, ZrF4, BaF2, GdF3, and AlF3. Using these purified materials and a “build-in casting” method, the low-transmission-loss of 8.5 dB/km at 2.12 µm was o btained, which is the lowest loss in an infrared ray transmitting fluoride glass fiber. The impurity level of the fiber was estimated as below 0.5 ppm by loss-factor analysis.
Effect of Pre-Annealing in Preventing Gate Oxide Breakdown Voltage Degradation Induced by Polysilicon Gate Delineation Using Ion Milling
Authors: Yamauchi Noriyoshi , Yachi Toshiaki , Wada Tsutomu
Published: November 2005

Polysilicon gate MUS capacitors were fabricated using Kaufmann-type ion milling apparatus in gate electrode delineation. The breakdown voltage of the MOS capacitors was degraded when the polysilicon sheet resistance at the start of ion milling was higher than 20 kΩ/□. The degradation was prevented when the polysilicon sheet resistance was lowered by annealing to less than 2 kΩ/□ before ion milling.
Optical Properties of a-Si:H Ultrathin Layers
Authors: Munekata Hiro , Kukimoto Hiroshi
Published: November 2005

Optical properties of hydrogenated amorphous Si (a-Si:H) in a-Si0.2C0.8:H/a-Si:H/a-Si0.2C0.8:H heterostructures are studied with emphasis on the quantum size effect in an amorphous system. When the thickness of the a-Si:H well layer is reduced to about 25 A, a notable change in optical gap as well as the shape of absorption spectra is observed, while the infrared emission band remains unchanged. The results are explained on the basis of the quantization of the carrier motion in the extended states of the confined a-Si:H. A potential application of the amorphous heterostructure is presented.
Calculation of Electron Attachment Rate Coefficient in Fluorine
Authors: Hayashi Makoto
Published: November 2005

Electron attachment rate coefficients have been calculated for fluorine by the Boltzmann equation. The range of E/N, ratio of the electric field to the gas number density, for which the coefficients were calculated ranged from 70 to 2000 Td.
Characteristics of Polythiophene Battery
Authors: Kaneto Keiichi , Yoshino Katsumi , Inuishi Yoshio
Published: November 2005

A secondary battery utilizing polythiophene films as cathode and anode active materials in an electrolyte of TBABF4/MeCN is studied. The cell potential, energy density and maximum power density (based on the weight of cathode and anode films) are observed to be 3.1 V, 93 Wh/kg and 89 kW/kg, respectively, for the dopant concentration of 24 mol%.
Single Crystalline Germanium Island on Insulator by Zone Melting Recrystallization
Authors: Takai Mikio , Tanigawa Takaho , Gamo Kenji , Namba Susumu
Published: November 2005

Single crystalline germanium islands on insulator have been formed by zone melting with graphite strip heaters. Two types of geometrical patterns for islands, a series of rectangles with 100 µm × 80 µm sides connected with a narrow stripe 30 µm × 10 µm and an isolated island (250 µm × 100 µm) with a peaked side, were successfully used to obtain large single crystalline islands. Most islands were found to be single crystal and the predominant orientation was <100>. Electron concentrations of 1016-1018/cm3 with Hall mobility of 3×103-103 cm2/Vsec were obtained for single crystalline germanium islands.
Elimination of Persistent Photoconductivity and Improvement in Si Activation Coefficient by Al Spatial Separation from Ga and Si in Al–Ga–As:Si Solid System –a Novel Short Period AlAs/n-GaAs Superlattice–
Authors: Baba Toshio , Mizutani Takashi , Ogawa Masaki
Published: November 2005

A superlattice with an exceptionally short period composed of 15 Å AlAs and 25 Å selectively Si doped GaAs is grown by molecular beam epitaxy (MBE). The persistent photoconductivity (PPC) is drastically decreased by the Al and Ga separation, and deep level formation is effectively suppressed by the Al and Si separation compared with n-Al
x
Ga1-x
As (x>0.25), which has the same bandgap as the superlattice. Consequently, an extremely high quality Al–Ga–As:Si solid system is realized for the first time with high donor activation coefficient and low activation energy (<10 meV) for thermal carrier generation.
Effect of Anode Surface Structure on Extracted Ion Beam from Br Pulsed Ion Diode
Authors: Yoneda Hitoki , Horioka Kazuhiko , Takahashi Tsutomu , Kasuya Koichi
Published: November 2005

Effects of anode surface structure on the extracted ion beams from a magnetically insulated diode are examined. Experimental results can be explained qualitatively with two kinds of contributions. The one is the probability of surface flashover, and the other is the energy dissipation according to the capacitance change in diode which affects the production of the anode plasma. Another contribution must be introduced for the case of a refrigerated H2O ion source.
Inspection of Micro Devices over the Passivation Top-Layer Surface Using the Low Voltage SEM
Authors: Uchikawa Yoshiki , Ikeda Susumu
Published: November 2005

Applicability of the low voltage scanning electron microscope to inspection of ICs and LSIs finished with the passivation layer was carefully explored. Experiments with kilo-electronvolt primaries demonstrated that there exist appropriate irradiating conditions of primaries where the passivation surface of MOSFET devices can be imaged without charging disturbances. It was shown that contrasts arise from different voltages applied to the electrodes underneath the passivation layer and also that they disappear as imaging continues. Linearities between the contrast variations and the applied voltages were found.
Thermally Deactivated-Type High Field Conduction in Poly-p-Xylylene Thin Films Polymerized in Vapor Phase
Authors: Takai Yoshiaki , Fujii Mahito , Hayase Yoshihiko , Mizutani Teruyoshi , Ieda Masayuki
Published: November 2005

Electric currents in poly-p-xylylene thin film (300∼400 nm) were found to show a negative temperature dependence at temperatures below the glass transition temperature and at high fields over ∼2 MV/cm. The high field conduction current strongly depended on the electrode metals and was accompanied by electroluminescence emission mainly in the visible region. These phenomena were explained by a model of the hole injection, collision ionization and recombination emission.
Large Area Exposure in Synchrotron Radiation Lithography Utilizing the Steering of the Electron Beam in the Storage Ring
Authors: Tanino Hiroshi , Hoh Koichiro , Hirata Masahiro , Ichimura Shingo , Atoda Nobufumi , Tomimasu Takio , Noguchi Tsutomu , Sugiyama Suguru , Yamazaki Tetsuo
Published: November 2005

It is demonstrated that the vertical (normal to the plane of electron orbit) width of exposed region in synchrotron radiation lithography can be expanded by a factor of more than three by steering the electron beam in the storage ring with a horizontal magnetic field, without losing intensity and homogeneity. The vertical distribution of the developed thickness in the resist and its vertical shift with the steering magnetic field are evaluated. The perturbation in the electron orbit is also estimated from the shifts of soft X-rays and visible illuminated regions.
Efficiency Enhancement in DC Pulsed Gas Discharge Memory Panel
Authors: Okamoto Yukio
Published: November 2005

Much improvement in the luminous efficiency of a dc pulsed gas discharge memory panel for color TV display was achieved by shortening the sustaining pulse duration. High energy electrons can thus be produced in the pulsed discharge with fast rise times. Calculated optimum value of E/P in a Xe gas discharge is 7–8 V/cm·Torr.
Formation of Lead Clusters in Supersonic Nozzle Expansion: Effect of Nozzle Geometry
Authors: Saito Yahachi , Mihama Kazuhiro , Noda Tamotsu
Published: November 2005

Atom-clusters of lead have been produced by adiabatic expansion of the vapor through small nozzles. Effect of nozzle geometry on the formation of clusters has been studied by time-of-flight mass spectrometry following the electron impact ionization. Three kinds of nozzle forms, converging-diverging, converging, and straight nozzles, have been investigated. Of the three, the converging-diverging nozzle produces clusters most effectively. Throat diameter also affects the cluster formation; the mean cluster size becomes larger for the larger throat among three different diameters, 0.3, 0.5 and 0.7 mm.
High Al-Content Visible (AlGa)As Multiple Quantum Well Heterostructure Lasers Grown by Metalorganic Chemical Vapor Deposition
Authors: Kawai Hiroji , Matsuda Osamu , Kaneko Kunio
Published: November 2005

High Al-content multiple quantum well heterostructure lasers, consisting of five (Al0.14Ga0.86)As wells 150 Å thick separated by four (Al0.35Ga0.65)As barriers 40 Å thick have been grown by metalorganic chemical vapor deposition (MOCVD) in an atmospheric pressure. The laser with a self aligned narrow stripe geometry is formed by the two step epitaxial technique. The room temperature CW threshold current for a device 250 µm long is typically 50 mA, which is 30% less than that of a conventional DH laser of the same geometry. Emission wavelength is 782 nm and the characteristic temperature T
0 is 232 K.
Effect of Electrical Conductivity of Substrate on RF-Sputter-Deposition of µc-Si:H at -180°C
Authors: Hashimoto Shin , Miyasato Tatsuro , Hiraki Akio
Published: November 2005

The µc-Si:H was fabricated by the reactive RF-sputtering technique onto low temperature substrate (-180°C). It has been found that the electrical conductivity of the substrate plays a significant role in the fabrication of µc-Si:H, i.e., the –SiH3 rich µc-Si:H is produced on the insulating substrate but the –SiH2– rich one on the conductive substrate. The substantial effect of the electrical conductivity of the substrate is assumed to be that the screening potential by the accumulated electric charge on the insulating substrate reduced the kinetic energy of ions which impinge onto the substrate.
Structure Analysis of the NiSi2/(111)Si Interface by the X-Ray Standing Wave Method
Authors: Akimoto Koichi , Ishikawa Tetsuya , Takahashi Toshio , Kikuta Seishi
Published: November 2005

The atomic structure of the NiSi2/(111)Si interface was investigated by the X-ray standing wave method using synchrotron radiation at Photon Factory. The angular yield of Ni K fluorescent X-rays was measured around the Bragg peak of a substrate Si. By comparing the profile of the experimental curve with that of calculated one, the interface atomic structure was determined.
Fabrication of a New Multilayered Amorphous Silicon Photoreceptor Drum by Glow Discharge Method
Authors: Kakinuma Hiroaki , Nishikawa Satoshi , Watanabe Tsukasa , Nihei Kohji
Published: November 2005

A new multilayered amorphous silicon photoreceptor drum has been developed by means of glow discharge method. Its structure was Al/a-Si: H(p)/a-Si: H(i)/a-SiC: H. The a-Si: H(p) and a-SiC: H act as a blocking layer for electron and hole respectively. The a-SiC: H layer also proved to be an excellent surface passivation layer. The a-Si: H(i) layer was deposited at a rate of ∼12 µm/h by the high power decomposition of a high flow rate pure silane. Excellent electrophotographic properties were obtained: initial surface potential ∼600 V for +7 kV corona, dark half decay time ∼5 sec and photosensitivity ∼0.5 µJ/cm2 at λ=632.8 nm.
Intrinsic Limitations on the High Speed Performance of High Electron Mobility Transistors
Authors: Chiu L. C. , Margalit S. , Yariv A.
Published: November 2005

An order of magnitude calculation has been performed for the qualitative comparison of the polar optical phonon limited electron mobility and drift velocity in GaAs/AlGaAs high electron mobility transistor (HEMT) and ordinary GaAs MESFET.
Low-Field Phonon-Limited Mobility in Semiconducting Heterojunction Structures
Authors: Lee Johnson , Vassel M. O.
Published: November 2005

We have calculated the drift mobility of a quasi-two-dimensional electron gas at an AlGaAs/GaAs interface as limited by acoustic deformation and polar optical phonon scattering, using a relaxation time approximation for the electron distribution function and a momentum-conservation description of the confined motion. The confining potential profile was modeled by an infinite triangular well and by a finite asymmetric square well. Mobility calculations included inter- as well as intra-subband scattering. We have found that the scattering rate is considerably larger than the momentum relaxation rate. Both rates show discontinuities at a multiplicity of energies due to the existence of bound states in the wells. As expected, the mobilities calculated from the momentum relaxation time are larger than those given by the scattering rate and therefore compare more closely with the experimental data. At a given temperature, the calculated mobility as a function of internal field F (square well width d) is dominated by polar optical scattering at lower F (larger d) but by acoustic scattering at higher F (smaller d).
Reignition Voltage and Arc Voltage on Contaminated Insulator Surfaces
Authors: Kaga Akio , Sato Masashi , Akagami Hideo
Published: November 2005

This paper reports investigations of flashover phenomena on insulator surfaces contaminated by NaCl. It discusses the relations between the reignition and the arc voltages, a high alternating voltage with a 50 Hz power frequency is applied to a contaminated insulator surface. The discharge characteristics in air on insulator surfaces are also discussed. These characteristics were obtained between non-contaminated electrodes, and the results are compared with those obtained with contaminated electrodes. The flashover characteristics in air were found to be very different from those on a contaminated surface. This means that under NaCl contamination, the reignition and the arc voltages are greatly influenced by the behavior of Na ions in discharge space and arc column.
New Method of Measuring Underlying Conductivity in Highly-Insulating Materials, with its Application to Nonlinear Conductivity of TTF-TCNQ
Authors: Kubota Hiroshi , Masumi Taizo , Anzai Hiroyuki
Published: November 2005

A new method of observing transport phenomena in highly-insulating materials is reported. The method overcomes several of the difficulties involved in measuring the conductivity of these materials. The usefulness of the method is shown by using it to observe the nonlinear conductivity of TTF-TCNQ at low temperatures.
Electric Field Induced Oscillatory Domains in a Nematic with Positive Dielectric Anisotropy
Authors: Krishnamurthy K. S.
Published: November 2005

Coherent Williams domain oscillations have been observed under AC excitation in a nematic with positive dielectric anisotropy. The special features of these oscillations are described and compared with those of similar oscillations observed recently under DC excitation in a nematic with negative dielectric anisotropy. In particular, it is brought out that such oscillations are not necessarily caused only by DC electric fields.
AC Measurement of Seebeck Coefficient in Disk-Shaped Semiconductors Using CW-Lasers
Authors: Kawai Masatoshi , Miyakawa Toru , Tako Toshiharu
Published: November 2005

A method for the AC measurement of the Seebeck coefficient of semiconductor materials is presented. In the method, a disk-shaped sample is partially irradiated with a chopped-light beam from a CW–CO2 laser, enabling us to estimate the rapid temperature variation of an inhomogeneously-heated sample by measuring the change in its electrical resistance. The inhomogeneity factor F, the ratio of the temperature coefficient of the electrical resistance under a nonuniform change in the temperature of the sample to that under a uniform change, is also presented. The values of the Seebeck coefficient for disk-shaped p-Ge and n-TiO2 samples obtained from the AC-measurement are in good agreement with those from the conventional DC-measurement to an accuracy of 10%.
Preparation of Low-Reflectivity Amorphous Silicon Using DC Magnetron Sputtering
Authors: Makino Takahiro , Kamoshida Kazuyoshi , Yamamoto Eiichi
Published: November 2005

The optical properties of dc magnetron-sputtered amorphous Si (a-Si) films grown under different Ar pressures (1.5≤P
Ar≤12 mTorr) and substrate-target distances (5≤l
s-t≤30 cm) were investigated. The reflectivity was found to decrease with increasing P
Ar and l
s-t, or equivalently with decreasing film density, and was 0.22 at λ=436 nm for the film with the lowest density. The absorption coefficient for this lowest reflectivity film was larger than 1×105 cm-1 at λ=436 nm. These optical properties meet the requirements for anti-reflective coatings in photolithography. Low-reflectivity a-Si could be obtained under deposition conditions for which P
Ar·l
s-t was larger than 150 mTorr·cm. The low density and low reflectivity were found to be due to a self-shadowing effect and thermalization of sputtered Si atoms.
Theoretical Considerations on ZnTe-Iodine Transport in a Closed-Tube System
Authors: Nishio Mitsuhiro , Ogawa Hiroshi
Published: November 2005

The AN (Arizumi and Nishinaga) theory is modified by adopting different values of the diffusivitity for different gas species. This approach enables us to give an absolute value of the transport rate, because it contains no unknown parameters. The theoretical calulation by this model is applied to the analysis of ZnTe-iodine transport in a closed-tube system, and it is established that the mean diffusivity (D
0) varies from 0.038 cm2/s to 0.015 cm2/s in the range of iodine concentration from 2×10-3 mg/cm3 to 2×10-1 mg/cm3 as a result of the appearance of two different main reactions depending upon the iodine concentration. It is concluded that this analysis is valid for explaining a transport process with more than one main reaction, whereas the AN calculation gives a good description only for a system dominated by a single main reaction.
Effects of Phosphorus Implantation and Post Annealing on Palladium Silicide Schottky Barrier Diode Characteristics
Authors: Kikuchi Akira
Published: November 2005

Schottky barrier diodes were fabricated on silicon surfaces whose impurity concentrations were controlled by ion implantation of phosphorus. The barriers were produced by Pd2Si. The forward voltages of these Schottky barrier diodes showed far greater lowering than predicted for implanted doses of 5×1013 cm-2 and higher. This was due to the reduction in the effective barrier height caused by accumulation of the phosphorus atoms at the Pd2Si–Si interface during the formation of the Pd2Si. This lowering is enhanced by post annealing after the formation of the Pd2Si.
Backscattering Studies of Negatrons and Positrons from Thin-Elemental Targets
Authors: Singh M. , Sharma K.
Published: November 2005

Backscattering of 32P negatrons and 22Na positrons has been studied as a function of target thickness in targets of aluminium, copper, tin and lead. The values of target thickness corresponding to saturation backscattering intensity are found to be independent of the nature of target and geometry of experiment but are different for negatrons and positrons. The Z-dependence of thin-target backscattering of negatrons and positrons is represented by an index whose values are found to be 2.0±0.1 and 1.72±0.05 respectively. These are found to be independent of the geometry of the experiment. The lower value of Z-dependence for positrons can be ascribed to their lower scattering cross-sections.
XPS Study of Thin Thermal Oxide Films on PbIn Alloys
Authors: Suzuki Mineharu , Hayashi Takayoshi
Published: November 2005

Properties of the thermal oxide films of PbIn alloys have been studied by means of XPS. Prior to the oxidation, Ar sputtering and subsequent storage in UHV were carried out in order to relax the sputtering effect. The oxide films were then formed by exposing the alloys to O2 for 30 minutes. Pb oxide and In oxide were determined to be PbO
x
and In2O3 according to their XPS chemical shifts. By using angle resolved-XPS, PbO
x
was found to exist in a small oxide layer. On the assumption that an oxide layer consists of an overlying PbO
x
, layer and an underlying In2O3 layer, the thickness for each layer was also measured by XPS. The total oxide thickness has a maximum at In ∼12 wt.% in alloy. The In2O3 volume fraction in oxide layer increases monotonically with an increase of In concentration in alloys, and PbO
x
is formed only in the region below In ∼30 wt.%.
Electrical Transport and Electron Spin Resonance in Electron-Beam-Irradiated Polyacetylene in the Presence of SF6 Gas
Authors: Hayashi Shigenori , Ishii Gaku , Yoshino Katsumi , Okube Jiro , Moriya Tomoyoshi
Published: November 2005

Electron-beam-irradiated polyacetylene, (CH)
x
, in the presence of SF6, is investigated by means of dc-conductivity and electron spin resonance (ESR) measurements. The electrical conductivities of cis- and trans-(CH)
x
doped with SF6, which has no effect on the conductivity in the usual vapour-phase doping, are found to be enhanced, and the sample weight to be increased, by electron-beam irradiation. The ESR line width of cis-(CH)
x
is dramatically decreased by irradiation in the presence of SF6. These experimental facts indicate that the electron beam induces the formation of a charge-transfer complex, accompanied by simultaneous isomerization in the case of cis-(CH)
x
.
Construction of an Electron Diffraction Unit for Gases as Fitted for the Use of Photographic Sheet Films
Authors: Taguchi Masami , Iijima Takao
Published: November 2005

A new type of electron diffraction unit for the structural determination of gases has been constructed. The unit employs a telefocus electron gun of the Steigerwald type. Plastic sheet films are used as the photographic detector instead of the glass plates usually used in such units. To check the reproducibility of the film-setting and other relevant functions of the unit, a large number of diffraction patterns of CS2 were taken and the values of the C-S distance were examined. The reproducibility was found to be as good as that in experiments using glass plates. It was thus concluded that sheet films are suitable for use as photographic detectors in high-precision diffraction experiments. The systematic errors inherent in the present unit are discussed in this paper.
Epitaxial Growth of Se Films Deposited on UHV-Cleaved KI Irradiated by Electrons
Authors: Nagashima Seiichi , Ogura Iwao
Published: November 2005

The epitaxial growth of Se deposits on UHV-cleaved KI surfaces irradiated by electrons at a dose of 1014–1018 electrons/cm2 at 250–1000 eV has been studied by transmission electron microscopy and electron diffraction. In the absence of electron irradiation, the Se deposits have a strong preferred orientation (101̄0)Se//(001)KI and [0001]Se//[110] and [11̄0]KI. With electron irradiation, the (336̄8̄) plane of the deposits is approximately parallel to the substrate surface, and the [1̄100] direction of Se is parallel to the [100] and [010] of KI in addition to the above orientation. The epitaxial growth of the (336̄8̄) plane depends on the irradiation dose rather than on incident electron energy, and the deposition rate ranges from 0.5 to 8 Å/s. The morphology of the Se deposits changes drastically depending on the rate of deposition and/or time of exposure to a UHV atmosphere after electron irradiation.
Study of Oxidation of TiSi2 Thin Film by XPS
Authors: Yang Wei Yi , Iwakuro Hiroaki , Yagi Hideichi , Kuroda Tsukasa , Nakamura Shogo
Published: November 2005

Titanium was deposited on a single-silicon wafer and made to form TiS2 by thermal annealing in vacuum. Samples were then oxidized at temperatures from 100 to 1000°C for 60 min in air. When the oxidized TiS2 was studied by X-ray photoelectron spectroscopy (XPS) in conjunction with argon-ion sputtering, SiO2 was found to be dominant in the oxide products at various oxidation temperatures. Full-width at half maximum (FWHM) and Si/Ti atomic ratio analyses led to the conclusion that various Ti oxides exist in oxidized TiSi2, but that the intermediate Ti-silicides (TiSi and Ti5Si3) do not. The growth of a Ti-free layer of SiO2 at 1000°C was also observed. SEM micrographs showed that no surface morphologies varied before or after oxidation in air at temperatures from 100 to 800°C. Above 1000°C, however, the TiSi2 film was thermally grooved at its grain boundaries, and the grain sizes were increased. Analytic electron-microscope photographs showed that the crystalline grains consisted of TiSi2, but that the grain boundaries lay within the Ti-free zone.
Iron-Nitride Thin Films Prepared by Arc-Discharge-Type Ion-Plating
Authors: Umeda Kazuo , Kawashimo Yasushi , Nakasone Masami , Harada Shigehisa , Tasaki Akira
Published: November 2005

Ferromagnetic iron-nitride thin films were studied as part of a programme of research into recording media. Samples were prepared by using a new type of ion-plating called “arc-discharge-type ion-plating”. In order to ionize metal vapor and nitrogen gas effectively, a new ionization electrode was introduced between 2×10-4 and 2×10-3 Torr. Nitrized films were obtained when the films were prepared above 2×10-4 Torr. The composition of the films was analyzed using Mössbauer spectroscopy, and it was confirmed that the films were highly corrosion-resistant.
An Assessment of e-Beam Controlled Discharge Pumping in KrF and XeCl Lasers
Authors: Hara Hideo , Namba Susumu , Hoshino Akihiro , Takuma Hiroshi
Published: November 2005

The characteristics of KrF and XeCl laser media pumped by e-beam controlled discharge have been studied. A glow discharge easily turns into an arc in the KrF laser medium, in which Ar is used as a buffer gas, and a maximum enhancement ratio of 3 only was obtained. A glow discharge is much more stable in the XeCl laser medium, in which Ne buffer gas is used, and a maximum enhancement ratio of 6 was obtained by maintaining stable glow discharge for as long as the electron beam of 150 ns FWHM duration was injected into the medium. The amplification characteristics of the XeCl medium were studied, and a small-signal gain of 1.5%/cm, an absorption coefficient of 0.2%/cm, a saturation intensity of 1.2 MW/cm2 and an internal conversion efficiency of ∼4% were obtained at a pumping density of 0.2 MW/cm3. Thus, e-beam controlled discharge has been found to be useful in the low-pumping-density and long-pulse operation of XeCl lasers.
An Investigation of the Phase Locking of Laser Modes by Continuous Resonator-Length Variation I. Computer Simulation for a Unidirectional Traveling-Wave Ring Laser
Authors: Miyashita Toyokatsu
Published: November 2005

Nowadays, the mode locking of various kinds of laser is a well-established technique. However, the phase-locking phenomenon caused by continuous resonator-length variation, discovered experimentally by Smith in 1967, is very different from other phase-locking phenomena, and its mechanism is still unclear. This paper shows first how this phenomenon can be simulated by numerical calculation of the laser equations, and next describes how the phases and frequencies of the modes change, keeping the envelopes of the phase-locked pulses constant. The catastrophic change to or from the phase-locked state as a function of the rate of resonator-length variation obtained by our numerical calculation is in good agreement with the results of the experiments by Smith.
Hot Electron Effect in Short n+nn+ GaAs
Authors: Mori Toshihiko , Hamaguchi Chihiro , Shibatomi Akihiro , Ryuzan Osamu
Published: November 2005

Current-voltage characteristics are measured by applying pulse voltages in short n+nn+ GaAs with a channel length of 1 µm. The observed non-ohmic behavior is interpreted in terms of the hot electron effect, the analysis being made by taking into account the non-uniform electric field distribution due to the boundary conditions of the short semiconductors. The results reveal that the dependence of the electron mobility on the electric field is not simple as in n-Si, but is complicated by the transfer of hot electrons to the higher-lying conduction valleys. The analysis gives the spatial distribution of the electron drift velocity, indicating the existence of drift velocity overshoot. The observed maximum drift velocity is about 3.2×107cm/s.
Correlation between Plasma Dynamics and Emmision of Deuteron Beam, X-Rays and Neutrons in a Plasma Focus Discharge
Authors: Yamamoto Toshikazu , Shimoda Katsuji , Kobayashi Koji , Hirano Katsumi
Published: November 2005

The correlation between the plasma dynamics and the emission of a deuteron beam, X-rays and neutrons in a plasma focus discharge was investigated experimentally. The dynamics were observed using interferometry in the streak mode and framing mode, and the energy distribution of the deuteron beam was measured using a Thomson parabola analyzer. The plasma column was partially disrupted by the m=0 instability. The deuteron emission started some tens of nsec before the disruption of the plasma column, while the X-ray and neutron signals started some Lens of nsec after the disruption. The m=0 instability was observed in each discharge even if neutrons were not produced. It is concluded that the acceleration field of the ion beam giving the neutron yield is generated not by a rapid change in the plasma inductance but by an abrupt rise in the resistivity of the plasma.
The fine structure of the bubble formed in front of the current sheet propagating downstream was observed.
Nuclear Magnetic and Mechanical Relaxations in the γ-Loss Band of Linear Polyethylene Treated with Fuming Nitric Acid
Authors: Anada Yuichi , Kakizaki Maeko , Hideshima Teruo
Published: November 2005

Measurements of the NMR second moment and mechanical loss tangent for solution-crystallized polyethylene treated with fuming nitric acid at 80°C for 20 h reveal a relaxiation region around –140°C. The relaxation (correlation-time) spectrum for this relaxation region is in good agreement with that for the γ3-relaxation, which is one of the component relaxations of the γ-loss band of untreated polyethylene crystallized from the melt or solution. The γ1- and γ2- relaxations existing in untreated polyethylene are greatly decreased by this treatment. The observed change in the second moment in the γ3- region (ca. 1.5 gauss2), is explained as being due to the rotational motion of part of the ciliary chain on the lamellar surface. It is found that absorbed water changes this relaxation into a new one similar to the γ2-relaxation.
Electrooptic Properties and Raman Scattering in InP
Authors: Suzuki Nobuo , Tada Kunio
Published: November 2005

An accurate measurement of the linear electrooptic coefficient of InP in the wavelength range of 1.06–1.50 µm has been carried out. The results range from r
41
T=-1.32×10-12 m/V at 1.06 µm to r
41
S=-1.68×10-12 m/V at 1.50 µm. The Faust-Henry coefficient, C, of InP at 1.06 µm has also been determined from Raman scattering measurements. The result is C=-0.53, and is thus almost the same as for that of GaAs and GaP.
RF Sputtering Crystal Growth and Spectroscopy of Nd Doped Y3Ga5O12 Substrate for Optical Amplifier
Authors: Yamaga Mitsuo , Miyazaki Yasumitsu
Published: November 2005

Optical amplifiers are very important devices for optical communication and information processing. Nd doped YGaG thin film waveguides which can be used for optical amplifiers were prepared on YAG substrates by rf sputtering. Single crystalline films with high quality were made at the substrate temperature T
sub=750°C. The fluorescence spectrum of Nd ions with emission lines of width 20 cm-1 observed in the film coincided with that in YGaG bulk crystals. The amorphous films fabricated at T
sub=650°C exhibited a broad emission band with half-width at maximum of 200 cm-1, which is ascribed to the different Nd ions with slightly different surroundings. Longitudinal pumping for excitation of Nd ions in the single crystalline films with thicknesses of about 1 µm was much more efficient than transverse pumping.
Beta Ray Backscattering Studies from Multi-Component Systems
Authors: Singh M. , Sharama K. K.
Published: November 2005

Backscattering of beta rays has been studied from two alloy systems, nine compounds, and four systems of aqueous solutions by using three beta emitters, 147Pm, 204Tl, and 90Sr–90Y in an efficient reflection geometry. It is found that the intensity of backscattered radiation can be expressed in terms of the proportions of the constituents of the multi-component system in each case by using the concepts of effective atomic numbers and atomic weights thus allowing the extension of the `Z' dependence results for thick elemental targets to the case of multi-component systems. The importance of these studies in the analysis of multi-component systems is discussed
XPS Study on the Change of Surface Potential of GaSe and InSe Induced by Ar+ Sputtering
Authors: Tambo Toyokazu , Tatsuyama Chiei
Published: November 2005

The changes of surface potential, directly induced by Ar ion sputtering, have been studied using X-ray photoelectron spectroscopy for both p-type GaSe and n-type InSe with no dangling bonds on the cleaved surface. Since the sputtering makes the surface metal-rich in these compounds, it is then predicted that the surface potential dramatically changes. The change of work function due to sputtering is obtained by measuring the emission spectrum of slow secondary electrons. It decreases from 5.7 eV to 5.3 eV in GaSe and increases from 4.5 eV to 5.0 eV in InSe. The magnitude of band bending due to sputtering is estimated from the shift of core levels. It is found that the band bends downwards by about 0.2 eV in GaSe and upwards by about 0.6 eV in InSe. These experimental results are explained in terms of the thin metallic layer and the interface states on the sputtered surface.
Excitation Spectrum of 3.39 µm Tansmission Modulation by Tunable CW–CO2 Laser in p-Ge
Authors: Kawai Masatoshi , Tahira Kenichiro , Miyakawa Toru , Tako Toshiharu
Published: November 2005

Modulated intensity of the 3.39 µm CW–He–Ne laser transmitted through a p–Ge sample is studied as functions of the wavelength and intensity of the exciting CW–CO2 laser madulated at the same frequency. The “excitation” spectrum obtained exhibits a peak at around 10.6 µm and gives complementary information to the two-wave saturation spectrum obtained by Keilmann in the 3 µm region. The experimental result is analyzed as the superposition of thermal effect and of the heavy hole depletion effect. Good fit of the experimental data to the theoretical curves can be obtained for both excitation spectrum and modulation frequency dependence of signal amplitude and phase using parameters which we derived previously.
Electron Mobility Calculations of In0.53Ga0.47As Taking the Two-Mode Lattice Vibrations into Account
Authors: Takeda Yoshikazu
Published: November 2005

Multi-mode lattice vibrations have been observed in certain alloy semiconductors. Since the predominant scattering mechanism in compound semiconductors is longitudinal optical (LO) phonon scattering, the multi-mode lattice vibrations, that is, multi-LO-phonon mode, should be considered in the electron transport phenomena in such alloy semiconductors. In0.53Ga0.47As ternary alloy lattice-matched to InP is taken as an example which has the two-LO-phonon mode. The effects of the two-LO-phonon mode on the electron scattering phenomena and on the electron mobility are calculated and discussed, by taking into account the screening effect of the LO phonons by free electrons. The calculated results are compared with the recent experimental mobilities in terms of the electron concentration dependence and the temperature dependence.
Spectroscopic Investigation of Recombination Process in a Pulsed Discharge Plasma Using Laser Induced Fluorescence Technique
Authors: Usui Tatehito
Published: November 2005

The temporal behavior of the population density of the first excited level of the hydrogen atom in a pulsed discharge plasma of a helium and hydrogen mixture has been measured using the laser induced fluorescence technique, while the population densities of the higher excited levels have been determined from the emission measurements. The population density of each level shows a rapid enhancement in the early stage of afterglow. The experimental results are compared with the collisional-radiative model, including various dissociation processes of hydrogen molecules. The experimental results can be explained well with the model. The population mechanism of the first excited level in the afterglow is found to be sensitive to the optical escape factor of the Lα line
Nb-Oxide-Pb Josephson Tunnel Junctions Fabricated Using CF4 Cleaning Process (II)
Authors: Kato Yujiro , Michikami Osamu
Published: November 2005

The rf plasma cleaning conditions using a CF4 cleaning process (CFCP) giving high-quality junctions are discussed. The C-F radical chemical reaction provides a clean, damage-free Nb surface which is protected from oxygen dissolution by a carbon layer. The carbon layer is possibly effective in forming a high-quality tunnel oxide. The dependence of the maximum dc Josephson current on an external magnetic field shows a uniform current distribution. The total critical current spread was measured in arrays of 50 series-connected junctions with an area of 10×10 µm2 and was found to be within ±2.5% for the best sample at a mean current density of 10.6 kA/cm2.
Hard Magnetic MnAl and MnBi Ribbons Made from Molten State by Rapid Cooling
Authors: Nagata Yujiro , Sano Hiroyuki , Ohta Keizo
Published: November 2005

MnAl and MnBi ribbons were made from the molten alloys by the single-roller rapid-quenching technique, and their crystallographical, mechanical and magnetic properties were studied. Long, flexible MnAl ribbons were produced, and the ferromagnetic τ-phase was obtained by a simple annealing treatment. The best magnetic properties were B
r=3.75 kG,
I

H
c=1.83 kOe and (B
H)max=2.1 MGOe for 56 at%MnAl ribbon. The MnBi ribbons were short and brittle, but they appear to be more stable chemically than the cast alloy. The best characteristics of the MnBi ribbons were B
r=3 kG,
I

H
c=1.5 kOe and (B
H)max=1.6 MGOe.
Automated Indexing of X-Ray Laue Spots for Arbitrary Lattices
Authors: Ohba Ryoji , Yamada Hironori , Watanabe Hidehiro
Published: November 2005

A computer program has been developed for automatic analysis of the orientations of the crystallographic axes of crystals with arbitrary Bravais lattices of known structure using X-ray Laue photographs. The principle and main parts of the system are described. Examples of analysis performed by the system are also presented.
Raman Scattering Characterization of Residual Stresses in Silicon-on-Sapphire
Authors: Yamazaki Ken-ichi , Yamada Masayoshi , Yamamoto Keiichi , Abe Kenji
Published: November 2005

In order to characterize the residual stresses in silicon-on-sapphire wafers, polarized Raman scattering measurements were made by probing both from the silicon-free surface side and from the silicon/sapphire interface (sapphire substrate) side at three different wavelengths. These measurements are described here. A theoretical consideration of the Raman tensors and frequency shifts in silicon crystals stressed by unknown forces is also given in this paper. It is found that the residual stresses are not uniform, but are distributed in the direction normal to the silicon film plane. The residual compressive stress is relaxed from the interface toward the silicon-free surface with an accompanying shear stress. The residual compressive stress is estimated to be 6.0×108∼13.0×108 N/m2 at the silicon/sapphire interface and 5.5×108∼7.5×108 N/m2 at the silicon-free surface.
Raman Studies of Internal Stress and Crystallinity of Pulse-Laser-Irradiated Silicon on Sapphire (SOS) in Relation to Hall Mobility
Authors: Nakamura Minoru , Kobayashi Yutaka , Usami Katsuhisa
Published: November 2005

The changes in internal stress and crystallinity in silicon- on-sapphire (SOS), as caused by pulse laser irradiation, were evaluated by Raman spectroscopy. The vertical distributions of the internal stress and the crystallinity in the silicon layer were found to be significantly affected by the number of laser pulses, although the energy density and width of the laser pulses were kept constant. The change in electron Hall mobility due to laser irradiation is discussed in relation to the internal stress and crystallinity of the SOS. An excessive number of pulses causes a reduction in the orientational order of the constituent crystallites in the silicon layer, with a decrease in the electron Hall mobility.
Mechanism of MOCVD Growth for GaAs and AlAs
Authors: Takahashi Yasuhito , Soga Tetsuo , Sakai Shiro , Umeno Masayoshi , Hattori Shuzo
Published: November 2005

The dependence of the growth rate of MOCVD-grown GaAs and AlAs on the growth temperature and the V/III ratio was investigated. It was found that (1) the growth rate suddenly began to decrease above a critical temperature T
c, (2) the uniformity in the layer thickness deteriorated above T
c, and (3) the growth rate of GaAs began to depend on the V/III ratio above T
c while that of AlAs did not. A new growth mechanism including Ga atoms and Ga-complexes as the active species contributing to the growth is proposed, and it is shown that the most plausible Ga-complex consists of [GaAs]
n
molecules.
Selenium Thin-Film Solar Cell
Authors: Ito Hideo , Oka Masayoshi , Ogino Toshio , Takeda Akitsu , Mizushima Yoshihiko
Published: November 2005

A new selenium thin-film solar cell of superior performance has been developed. The cell incorporates an SnO2/CdSe/Se/Au structure and is fabricated at 250°C or lower by vacuum evaporation only. The maximum efficiency is attained at 60°C, and its value is 4.6% for an AM 1 (Air Mass 1), 100 mW/cm2. This indicates the possibility of using the cell at higher temperature. V
OC, I
SC and F
F are 0.65 V, 13.5 mA/cm2 and 52%, respectively. The efficiency at 400 lx under a fluorescent lamp is 11.6%.
The cell characteristics improved with aging owing to stress release, and stabilized after 40 days at room temperature. Stresses within the selenium film and the internal series resistance are regarded as the major factors determining the cell quality. This paper discussed the mechanism of operation of the cell, an MIS structure including a Schottky barrier.
An Introduction to Applied Cosmic Ray Physics
Authors: Kodama Masahiro
Published: November 2005

This paper describes some possible practical applications of cosmic radiation. One example of this is the measurement of the water equivalent of snow using cosmic-ray-produced neutrons. The technique used in this has also been tried under the ground, where it has a potential use in estimating the moisture content of soil. Another possibile application is in estimating upper atmospheric temperatures from cosmic ray muon components, and this has actually been tried and found feasible. These examples have led us to establish a new field of study–“Applied Cosmic ray Physics”.
Ablation Accelerator (ABLAC) as Driver for Impact Fusion
Authors: Ikuta Kazunari , Ueno Isao , Tanimoto Mitsumori
Published: November 2005

This paper presents considerations on the design both of an ablation accelerator suitable as a driver for impact fusion, and a projectile to be accelerated by the accelerator. We argue that the proposed approach offers an attractive option for accelerating an iron projectile to hypervelocities suitable for fusion applications.
Differential Scanning Calorimetry of the Coalescence Growth of Fine Smoke Particles
Authors: Maeda Shigeo , Iwabuchi Shohei , Shiojiri Makoto
Published: November 2005

To determine the mechanism of coalescence of fine particles in smoke produced by gas evaporation, mixture of Ag smoke particles and Cu smoke particles were examined by differential scanning calorimetry. A broad exothermic peak appeared between 10 and 500°C, and a sharp endothermic peak near the eutectic point of the bulk Ag–Cu alloy, The integrated heat of the exothermic peak is ascribed to the reduction of the overall surface energy of the particles by the coalescence. The coalescence of the fine particles is interpreted here using a theory of sintering by atomic diffusion.
Surface Diffusion of Sulfur on Oxygen-Covered Tungsten Studied by Auger Electron Spectroscopy
Authors: Ishikawa Kazuo , Tanemura Masaki
Published: November 2005

By the electron-beam bombardment of a tungsten surface in an ultrahigh vacuum, we can obtain the surface distribution of sulfur, which localizes at the area of bombardment. Utilizing this phenomenon as a method of depositing localized sulfur, a study was performed by Auger electron spectroscopy on the surface diffusion of sulfur on a polycrystalline tungsten ribbon surface covered with roughly half a monolayer of oxygen. As a result, the activation energy for the surface diffusion of sulfur was determined as 1.03±0.04 eV.
Comparative Study of Anisotropy Fields in Garnet Films
Authors: Murthy V. R. K. , Belt R. F.
Published: November 2005

Measurements of the anisotropy fields were performed on “as grown” Bi-TmFeGa Garnet, Bi-YIG and commercial 2 µm bubble film with compositions that were grown on [111] GGG substrates. Results from three independent measurement techniques of the anisotropy field are compared and reported. These techniques are the dynamic susceptibility (MO), ferromagnetic resonance (FMR) and visual (V) observation of the domain pattern in a changing inplane field. The three measurements give results to agree within 5–10% of each other neglecting the cubic anisotropy energy's contribution. The advantages and limitations of each technique for routine characterization of the magnetic films are discussed.