bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dynamic Properties of a Monolithic Mechanism with Notch Flexure Hinges for Precision Control of Orientation and Position
Authors: Tanaka Mitsuru
Published: November 2005

An algorithm for estimating the elastic coefficient, eigen frequency and effect of disturbing vibrations in the environment is derived for a monolithic mechanism with notch flexure hinges used for precision adjustments. The feasibility of the algorithm for the actual design of mechanisms is confirmed by experiments on a mechanism consisting of a quadrilateral of links. The concept of reduction of a diagram is introduced to simplify design procedures for such mechanisms, and several important examples of the mechanisms are described. The generalized algorithm for estimating the dynamic properties of a link mechanism with notch flexure hinges is discussed with a view to developing a software system for computer-aided design.
State of Hydrogen in BCC Metals: Its Quantum-Mechanical Character
Authors: Fukai Yuh
Published: November 2005

A consistent quantum-mechanical description is given of some atomistic properties of hydrogen isotopes in bcc metals, including in particular the energy and wave functions of a hydrogen atom, its preference of the type of interstitial sites, distortion of the surrounding lattice, and its effects on crystal structure. A general systematics in the site-preference–a transition from T sites to O sites in more congested circumstances–is noted and explained physically. Results of our recent experiments on hydrogen in V and Fe are also presented.
A 10.7-m Grazing Incidence Spectrometer for the Study of Highly-Ionized Atoms
Authors: Ando Kozo , Mori Kazuo , Okazaki Kiyohiko
Published: November 2005

A high-resolution grazing incidence spectrometer has been constructed for the purpose of analysing the spectra of highly-ionized atoms. The diameter of the Rowland circle is 10.7 m and the grazing angle can be varied from 0.5 to 1.0 degrees. The wavelength coverage is from 100 Å down to several Å. The characteristics of the spectrometer are described here in detail. The shortest wavelength observed in our light source is the 8.34 Å line of Al Kα. The resolution is found experimentally to be better than 0.016 Å at about 42.2 Å, judged from two close lines of the Mo XVII spectrum taken with an entrance slit 3 µm wide and a grating of 300 grooves/mm. This spectrometer is used mainly as a spectrograph, but it can also be used as a monochromator.
Conduction of Sodium and Nonbridging Oxygen Ions in Sodium Silicate Glass
Authors: Doi Akira
Published: November 2005

From thermally-stimulated polarization/depolarization current studies of bulk glasses of Na2O–2SiO2 and Na2O–3SiO2, the following conclusions were made. First, the great reduction of dc conductivity down to a few hundredths with decreasing sample thickness is explained in terms of the presence of inherent microheterogeneity in the glass structure. Second, the peak which previously was assigned generally as due to localized motion of nonbridging oxygen ions in the alkali-depleted region near the anode is better assigned as due to conduction polarization of those ions. Then the activation energy for conduction of nonbridging oxygen ions is estimated to be roughly 6±2 kcal/mole more than that for alkali conduction. And third, because of the high conductivity of bulk samples, degradation of alkali conduction by space charges accumulating near the electrodes during polarization generates the peak at around 10-8–10-7 Ω-1 cm-1.
Some Properties of Intrinsic and Phosphorus Doped Amorphous Silicon Thin Films
Authors: Ray Swati , Chaudhuri P. , Batabyal A. K. , Barua A. K.
Published: November 2005

The dark conductivity σD and the photoconductivity σPh of intrinsic and n-type (phosphorus doped) a-Si: H films prepared by rf glow discharge of silane gas has been studied. The samples have been prepared under different experimental conditions which include change of rf power, substrate temperature and dopant concentration. The most significant result has been the change in dark conductivity and photoconductivity with the change of rf power within a limited range of 2 to 30 Watts. As shown by infrared spectroscopy the chances in σD and σPh with rf power are mainly due to the change of hydrogen content. The appearance of a kink in σD vs 1/T plot (at T' with higher slope at T>T') has been explained as due to the effect of statistical shift of the Fermi level E
F.
Some Electrical Properties of γ-Fe2O3 Ceramics
Authors: Nakatani Yoshihiko , Matsuoka Michio
Published: November 2005

We have observed some electrical properties of γ-Fe2O3 ceramics made by oxidizing Fe3O4. The change in electrical resistance during the oxidation from Fe3O4 and the transformation to α-Fe2O3 are discussed first. The effects of additives and mechanical treatment on the transformation of γ-Fe2O3 to α-Fe2O3 were also studied, by measuring the electrical resistance. A high gas sensitivity was observed in γ-Fe2O3 ceramics, and the gas sensitivity decreased as the amount of α-Fe2O3 precipitated in the γ-Fe2O3 increased. The transformation to α-Fe2O3 could thus be investigated by evaluating the gas sensitivity.
Growth of Cr Needle Crystals Induced by Field Electron Emission
Authors: Okuyama Fumio
Published: November 2005

This paper describes the growth of needle crystals of Cr on a field cathode operating in Cr(CO)6 vapor at 2–5×10-2 Torr. The products are classified into two categories depending on the magnitude of the applied potential; (1) thickly-distributed, tree-like needles obtained at 0.5–5 kV and (2) sparsely-distributed, fibrous needles obtained at higher potentials. The former needle growth is possibly promoted by Cr+ ions from a corona plasma while the latter is promoted by the same ions from an arc plasma. The needle morphology is sensitive to temperature in the former and to field strength in the latter. Both types of needle consist of agglomerated crystallites oriented randomly, and their structure can be an fcc one with a lattice spacing of about 4.14 Å. It is hypothesized that this fcc structure is attributable to the growth mode of the needles in an extremely strong electric field.
A New Microbridge with an Improved I-V Curve
Authors: Kobayashi Masanori , Musha Toshimitsu
Published: November 2005

The I-V curves of microbridges of uniform thickness and given geometry are calculated, and the results are in good agreement with those of Pb thin-film microbridges with the corresponding geometries. Using this result, we have designed a microbridge of new geometry with metallic balls at the edges of the bridge part which prevent the normal state from expanding into the electrodes when the electric current is increased. A very simple technique for fabricating this new microbridge is described. With the new microbridge, more Shappiro steps have been observed than with conventional microbridges, up to a voltage as high as 0.7 mV.
Unstable Regions in Type A1-x-yBxCyD III-V Quaternary Solid Solutions Calculated with Strictly Regular Solution Approximation
Authors: Onabe Kentaro
Published: November 2005

Solid-state immiscibility in type A1-x-y
B
x
C
y
D III-V quaternary solid solutions is analyzed on the basis of the strictly regular solution approximation. The calculated spinodal isotherms for various temperatures show that the existence of unstable regions, and hence miscibility gaps, which are always found on the ternary side, is a common feature of these quaternaries, although the extent of these regions depends strongly on the particular quaternary system and the temperature. Fairly large unstable regions are expected for quaternary systems with mixing on group V element sublattices at ordinary growth temperatures. These results indicate the limitations of these quaternaries for practical applications such as optical sources.
Electron Microscopic Study of Transition Structures Formed from Titanium Oxide Evaporated Films
Authors: Yamada Yukio
Published: November 2005

The transition structures made from films formed by evaporating TiO1.28 and TiO1.0 onto NaCl substrates have been studied by electron microscope. The structure of the films formed from TiO1.28 at various substrate temperatures is changed to transition structure I with ordered titanium-vacancy-rich planes by in situ heating in the electron microscope. On the other hand, transition structure II with ordered oxygen-vacancy-rich planes is formed in films made from TiO1.0 in the titanium-rich composition range. The former structure is found to be distorted more from the parent NaCl-type lattice than the latter, and their axial ratios c
f'/a
f' are 0.93 and 0.97, respectively. The difference in the distortion is discussed from the point of view of the difference in the atomic volumes of titanium and oxygen.
Ion Sampling Study in Gaseous Plasmas Using a Simple QMF
Authors: El-Kelish Salah , Uchida Yoshiyuki , Hattori Shuzo
Published: November 2005

A simply-constructed Quadrupole Mass Filter (QMF) was used to study the plasma ionic constituents in the positive column of a dc discharge. The instrumental calibration constant, the ratio of the detected ion current I
i to the electron density n
e produced at the positive column source, was measured as a function of the discharge pressure and current. The electron density n
e was measured by the floating double-probe method. Measurements in the low-pressure region of the discharge below 2 Torr showed an approximate proportionality between I
i and n
e, except for a slight dependence on discharge current and pressure. Some experimental data are reported on the ion current ratio measurements I(Ar2
+)/I(Ar+
) for argon discharge at pressures varying from 0.4 to 9 Torr and for a discharge current density of 220 mA/cm2. The ion ratios obtained here are compared with those obtained by other authors.
Plasma Electron Energy Distribution of a Beam-Plasma Type Ion Source
Authors: Ishikawa Junzo , Ektessabi Ali Motamed , Takagi Toshinori
Published: November 2005

The plasma electron energy distributions of a beam-plasma type ion source are experimentally investigated in relation to the ion source operational parameters. These parameters are the primary electron beam current (beam-plasma discharge current) and the pressure of the working gas. Using the experimental results, we show that the beam-plasma discharge is an effective method of heating a plasma, with the plasma electrons being distributed in the range of a few eV to a few tens eV. As a result, a plasma is produced with a density of more than 1011 particles/cm3. Beam-plasma type ion sources using the beam-plasma discharge are highly stable and controllable, and can be operated over a wide range of gas pressures and primary electron beam currents.
Monte Carlo Simulation of Energetic Ion Behavior in Amorphous Targets
Authors: Ishitani Tohru , Shimase Akira , Hosaka Sumio
Published: November 2005

A Monte Carlo calculation procedure for simulating the scattering processes of an energetic ion in amorphous targets is given. This computer program can be extended to any ion-target combination up to several MeV incident energy. A high degree of simulation accuracy is obtained independently of incident energy within a reasonable amount of computer time at high as well as low incident energies. Good agreement is obtained in the comparison with calculated depth distributions for implanted ions with the experiments and other Monte Carlo results.
Acoustic Velocity Measurements for Various Directions of Solid n-D2 at 136 kbar and 300 K by Billouin Scattering in a Diamond Anvil Cell
Authors: Shimizu Hiroyasu , Kumazawa Takao , Brody Edward M. , Mao Ho K. , Bell Peter M.
Published: November 2005

This paper presents a method of carrying out Brillouin scattering measurements using a diamond anvil cell. 45°, 60°, 90°, 120°, 135°, and 180° scattering geometries are used in order to determine the angular dependence of acoustical properties, and for each geometry the sound velocity (v) and the wave vector direction of the acoustic phonon are theoretically derived as a function of the refractive index (n) of the medium. It was found that, for normal scatterings at 60° and 90° and backward scattering at 120°, v can be determined simply by measuring the frequency shift independent of n. By applying this method to the study of solid n-D2 at 136 kbar and 300 K in a diamond cell, we have found that the sound velocities are independent of angle on the plane parallel to the diamond interfaces.
Computer Simulations of Quench Properties of Thin, Large Superconducting Solenoid Magnets
Authors: Kishimoto Takeshi , Mori Shigeki , Noguchi Masaharu
Published: November 2005

Measured quench data of a 1 m φ×1 m thin superconducting solenoid magnet with a single layer aluminum-stabilized NbTi/Cu superconductor of 269 turns were fitted by computer simulations using the one-dimensional approximation. Parameters obtained were used to study quench properties of a 3 m φ×5 m (1.5 Tesla) thin superconducting solenoid magnet with a stored magnetic energy of 30×106 J. Conductor dimensions with which the solenoid could be built substantially safe for the full field quench were optimized.
The Thickness-Dependence of Dielectric and Physical Properties of BaTiO3 Ceramic Thick Films
Authors: Yamashita Kimihiro , Hamano Takashi , Kaga Takao , Koumoto Kunihito , Yanagida Hiroaki
Published: November 2005

Ceramic films of BaTiO3 differ from bulk specimens in dielectric and other physical properties. In BaTiO3. films produced by a modified doctor blade method, the c-axis orientation along the direction perpendicular to the film surface was observed and the degree of orientation increased with decrease in film thickness. Elongation of c-axis was also observed in the films. The thickness dependence of the dielectric constant of the films was successfully estimated using the Lichtenecker-Rother equation. Further, an equation was presented to describe the effects of grain arrangement, crystal axis orientation, and porosity on a dielectric constant at room temperature.
Composition Modulations of InxGa1-xSb Crystals in Current Controlled Liquid Phase Epitaxy
Authors: Kumagawa Masashi , Takabe Yoshiyuki , Hayakawa Yasuhiro
Published: November 2005

Modulation of the indium concentration in In
x
Ga1-x
Sb crystals by the use of current controlled crystal growth is investigated. The indium concentration is increased by pulse current passed across the growth interface independently of the current direction and of the electrical conduction type of crystals. The total indium concentration is increased roughly linearly with the rate in the regrowth process, after the growth interface is remelted by the generation of the Joule and Peltier heats due to pulse current.
The Donor Level of V4+ and the Metal-Nonmetal Transition in SrTi1-xVxO3
Authors: Tsuiki Hideyasu , Kitazawa Koichi , Fueki Kazuo
Published: November 2005

The electrical conductivity of single crystalline SrTi1-x
V
x
O3 (0.1≦x≦1) was measured down to 4.2 K. The depth of the donor level of V4+ in SrTiO3 was about 0.6 eV. The metal-nonmetal transition occurred at x≃0.6 with σ≃280 Ω-1 cm-1 and the conductivity increased with x up to about 2×104 Ω-1 cm-1 at x=1. In the semiconducting region of x<0.6, the electrical conduction was of the activation type with a constant activation energy in the higher temperature range and with a decreasing activation energy in the lower temperature range. The temperature dependence of the electrical conductivity can be explained by hopping conduction in the donor band. The deep donor level, the metal-nonmetal transition at extremely large concentrations of donors and other results can be systematically explained by assuming the local Jahn-Teller distortion around V4+ ions.
Photo-Induced Current Transient Spectroscopy in High-Resistivity Bulk Material. I. Computer Controlled Multi-Channel PICTS System with High-Resolution
Authors: Yoshie Osamu , Kamihara Mitsuo
Published: November 2005

A computer controlled multi-channel PICTS system which allows one to detect many deep trapping levels in high-resistivity bulk material by only a single thermal scanning process, has been developed. In order to obtain the normalized PICTS signal, an automatic gain controlled pre-amplifier has been used. An expanded-scale technique which allows one to distinguish fine PICTS peaks has been proposed. This expanded-scale technique is very useful especially for the case when many PICTS peaks are closely superposed. In high-resistivity bulk CdS single crystal, it has been found that PICTS spectrum-shape and number of detected peaks depend strongly upon the wavelength of exciting laser light, and that the trap-parameters obtained are not strongly influenced by light intensity. The PICTS method may be superior on many points, especially in peak-separation, to the thermally stimulated current method.
Photo-Induced Current Transient Spectroscopy in High-Resistivity Bulk Material. II. Influence of Non-Exponential Transient on Determination of Deep Trap Parameters
Authors: Yoshie Osamu , Kamihara Mitsuo
Published: November 2005

Computer simulation and experimental study on the influence of non-exponential current transient upon the determination of the trap-activation energies and the capture cross sections in PICTS have been performed. The condition of sampling times t
1 and t
2 (t
1<t
2) should not be such that t
1 is fixed and t
2 is varied since large errors are introduced into the obtained trap-parameters, while the condition that t
2/t
1 is fixed and both t
1 and t
2 are varied, should be used in order to minimize the errors. By using a computer controlled multi-channel PICTS system which has a large number of sampling gates, the experimental study on the influence of non-exponential transient upon PICTS in a high-resistivity bulk CdS single crystal has been made possible. The results obtained experimentally in the bulk CdS for the non-exponential case have been found to agree well with the predictions of the simulation.
A Millimeter Wave Spectrophotometry by a Wide Band Oscillator of the Ledatron
Authors: Suto Shozo , Ikezawa Mikihiko
Published: November 2005

For the purpose of the wavelength scanning spectroscopy in the millimeter wave region, we have made a wide band oscillator using the Ledatron tube. The pulsed output signal is obtained in the wavelength range from 2.6 to 9 mm (1.1 to 3.9 cm-1) almost continuously. The peak output power is over several hundred milliwatts from 4 to 9 mm and over several tens of milliwatts from 2.6 to 4 mm. With this source, a spectrophotometer has been constructed in which light pipes are used as wave guides and the fluctuation of the signal is averaged by a boxcar integrator. A measurement of absorption spectra is demonstrated for a solid state sample of NaCl:OH-.
Effect of Electric Field and Polarity on Light Emission in Metal-Insulator-Semiconductor Structure Thin-Film Electroluminescent Devices
Authors: Ohwaki Jun-ichi , Kozawaguchi Haruki , Tsujiyama Bunjiro
Published: November 2005

Changes in the emission intensities and spectra with applied electric fields in Metal-Insulator-Semiconductor (MIS) structure thin-film electroluminescent (TFEL) devices have been investigated using devices with stacked emitting layer structures, such as ITO/ZnS: Mn/ZnS: Tb/Sm2O3/Al. In MIS-TFEL devices, the emission distribution in the direction of the ZnS film thickness is nonhomogeneous. In particular, the emission intensity in the region near the ZnS-insulator interface increases with increasing applied voltage more than in the other region in the ZnS layer, when electrons exciting emission centers are accelerated from the insulator side. On the other hand, the emission is homogeneous at the opposite polarity. It is found that the emission color for stacked emitting layer MIS-TFEL devices can be modulated by changing the applied voltage.
Injection Locking of a Nitrogen Laser Pumped Dye Laser
Authors: Inoue Yukio , Sakurai Takeki
Published: November 2005

Injection locking of a N2-laser pumped dye laser is investigated. The locking efficiency is measured as a function of injecting beam intensity, injecting beam wavelength, and delay time between an injecting laser pulse from a master oscillator and a pumping N2-laser pulse at a forced oscillator. The dye laser output of 1.2 kW with linewidth of 0.2 nm is obtained at locking efficiency ρ=0.8 when the injecting intensity is about 10 kW/cm2.
The Effect of the Magnetic Field in the Behavior of Magnetic Multipole Discharge
Authors: Oka Yoshihide , Kuroda Tsutomu
Published: November 2005

The role of the magnetic field in the behavior of magnetic multipole discharge is investigated experimentally by using a bucket type ion source with electromagnets. There exist two modes of discharge which transit each other in the critical current. The relation between the plasma density profile and the magnetic field is experimentally clarified by taking into account the filament position, that is, (1) the magnetic field strength near the filament must be below 80±20 G to get no peaked density profile, and (2) a region of a density uniformity better than 10% is obtained within 20±10 G contour. The dependence of the arc efficiency and the ion species composition on the magnetic field strength are studied and discussed.
Particle-Loss Reduction of Laser-Produced Anisotropic Plasmas by Means of a Uniform-Multipole Cusp Composite Magnetic Field Configuration
Authors: Noda Etsuo , Sekiguchi Tadashi
Published: November 2005

In connection with the problems of filling a relatively large magnetic container with a clean laser-produced hot plasma, a plasma blob with initial spatial anisotropy is produced within a uniform as well as a uniform-multipole cusp composite magnetic field configuration, and its behavior is observed in some detail. The results indicate that (1) there exist two separate physical mechanisms of particle escape across magnetic field, referred to as “plasmoid-type” and “drift-type,” and (2) both types of particle losses may be drastically reduced or suppressed by the (local) employment of the composite field. The results of approximate theoretical analysis on the basis of MHD-equations show good quantitative agreement with the experimental ones, and the magnetic-shear and/or spatial-gradient of magnetic field strength in the composite field are identified to be very effective for the reduction or suppression of these particle losses.
Sheath Potential Generated by a Relativistic Electron Beam
Authors: Ikuta Kazunari , Ueno Isao
Published: November 2005

It is reported that a new sheath structure is formed in a plasma where a relativistic electron beam is injected. An application of this new sheath to the pinched-plasma ion beam source is described in order to avoid the electron bombardment on the electrode.
Undercut in a CF4-Based High-Pressure Poly-Si Plasma Etch
Authors: Borghesani A. F. , Mori F.
Published: November 2005

The behaviour of the plasma etching of polycrystalline Si (P-doped and undoped) in a CF4-based high-pressure glow discharge is studied as a function of the power density, of the exposed poly-Si surface area (the so called loading effect), of the flow rate of CF3Cl and of the flow rate of N2O and O2 as additive gases.
Partially in contrast with the current results reported in the literature, the experimental data here presented show that P-doped poly-Si is etched slower than undoped poly-Si in the mixture CF4+CF3Cl+N2O as well as in the mixture CF4+CF3Cl+O2, probably as a result of the different interaction mechanisms between substrate and gaseous reactants, which could be established at such high pressure and flowrate as in our experiment.
Furthermore, our data reveal that the lateral etch rate (or undercut) is critically determined by the effective concentration of atomic F.
Finally, we observed that CF3Cl has a clear anisotropic mechanism of etch.
Measurement of Particle Velocity Using a Time Interval Distribution of Photoelectric Pulses
Authors: Fujii Ken-ichi , Suzuki Norihito
Published: November 2005

The usual laser Doppler velocimeter (LDV) cannot be used when the scattered light intensity is so low that the output of a detector becomes a chain of photoelectric pulses instead of an analytic burst signal. The usual LDV is also unsuitable when particle concentration is high. In this paper, the time interval distributions of photoelectric pulses in the LDV system and the local oscillator heterodyne (LOH) system are investigated. The particle velocity is obtained from the time interval distribution of photoelectric pulses.
Microchannel Plate Position Sensitive Detector System for Charge Analysis of Low Energy Heavy Ions
Authors: Hanaki Hirofumi , Nagai Nobuo , Kusakabe Toshio , Horiuchi Tadahiko , Sakisaka Masakatsu
Published: November 2005

A position sensitive detector (PSD) using a microchannel plate (MCP) of rectangular shape (46 mm × 13 mm) is developed and applied to measure the charge spectrum of low energy heavy ions. An analog position processor with a swift log-antilog operation is devised, which has a wide dynamic range of 50 mV–10 V suitable for the MCP pulse properties. A digital processor employing two 8 K channel ADC's and a minicomputer is also presented for comparison. The well resolved spectra are obtained when multiply charged heavy ions are separately and locally incident on the PSD.
Effect of Deposition Conditions on Intrinsic Stress in a-Si: H Films
Authors: Ozawa Kiyoshi , Takagi Nobuyoshi , Asama Kunihiko
Published: November 2005

Intrinsic stress in the a-Si: H film, which reflects the internal microstructure of the film under deposition and thus gives the information about the construction of amorphous network, has been evaluated by the Baser interferometric method.
The intrinsic stress induced in the a-Si: H film is compressive and increases with the deposition temperature. As the intrinsic compressive stress is increased, decreases are observed in the deposition rate, the total hydrogen concentration, and the ratio of hydrogen concentration with the configuration SiH2, SiH3, and (SiH2)
n
to that with SiH. These results on the temperature dependence of a-Si: H film growth indicate that the contribution of excited species in the plasma to the growth of the a-Si: H is restricted by the intrinsic compressive stress induced in the a-Si: H through differences in molecular dimensions of the excited species.
Time-of-Flight Measurement of Undoped Glow-Discharged a-Si:H
Authors: Shirafuji Junji , Matsui Hirosuke , Inuishi Yoshio , Hamakawa Yoshihiro
Published: November 2005

Time-of-flight measurement has been carried out on glow-discharged a-Si: H films. It is observed that the electron transport is fairly non-dispersive above room temperature, while holes have a highly-dispersive nature. In its temperature dependence, the electron mobility shows a tendency to saturate at higher temperatures and has an activation energy of 0.2 eV in the low-temperature region. From the saturation characteristic of the relation between the electron-induced charge and the applied field on thin samples, the µdτ product is estimated to be about 2.6-6×10-9cm2/V at room temperature. A model based on a multiphase structure of a-Si: H is proposed to explain, in a consistent manner, the characteristic transport of electrons and holes.
Effect of Sb Incorporation in Ge–S Glasses
Authors: Zhong Boqiang , Watanabe Ichiro , Shimizu Tatsuo
Published: November 2005

The optical gap and the glass transition temperature show monotonic and nonmonotonic changes with x in (Ge0.3S0.7)100-x
–(Sb0.4S0.6)
x
and (Ge0.42S0.58)100-x
(Sb0.4S0.6)
x
glasses respectively. The relationship between the optical gap and the glass transition temperature obeys the formula obtained by DeNeufville and Rockstad. The electrical conductivity is not greatly changed in either series of glasses, and the addition of Sb2S3 brings about no appreciable change in the ESR shape for Ge30S70, a higher g-shift for Ge42S58 and a decrease in the spin density for both glasses. These results can be explained by noting that the structure around Ge in Ge42S58 becomes S-richer by the incorporation of Sb2S3, whereas the structure of Ge30S70 tends to form solid solutions of GeS2 and Sb2S3 with excess S-S bonds.
The Alternating Quarter-Wavelength Layers Coating on 1.55 µm GaInAsP/InP Laser Facets
Authors: Ohtsu Motoichi , Kotani Hiroki , Tagawa Haruo
Published: November 2005

The alternating quarter-wavelength layers of MgF2 and ZnS were coated on the facets of 1.55 µm GaInAsP/InP BH lasers to decrease the threshold current by increasing the reflectivities of their facets. A precise optical thickness monitor was constructed, and its measurement error was about 3%. By coating five and six alternating layers, beginning with MgF2 as the first layer, the threshold currents were decreased to 83% and 79% of the uncoated lasers, respectively. Calculations of the reflectivities, by considering also the coupling loss at the end of the waveguide due to diffraction, give estimations of 68% and 84% for five and six layers, respectively.
Theory of CW-Laser-Induced Dynamic Grating by Inter-Valence-Band Absorption in p-Type Semiconductors
Authors: Kawai Masatoshi , Sato Heihachi , Miyakawa Toru , Tako Toshiharu
Published: November 2005

The formulation of James and Smith is extended to the case of two-wave excitation, and the diffraction efficiency of a 3.39 µm He–Ne laser beam diffracted by the heavy hole distribution function grating induced by two CO2 lasers in p–Ge is estimated as a function of the intensity and detuning frequency of the CO2 lasers.
The results of theoretical analysis are in good agreement with the experimental results reported in our previous letter on the angular spread of the diffracted beam and its dependence on the excitation intensity. The dependence of the diffracted beam intensity on the detuning frequency gives a relaxation time for the heavy hole distribution function T
h∼0.2 ps, in good agreement with our theoretical prediction.
Study on Zn Diffusion in GaAs and AlxGa1-xAs (x≤0.4) at Temperatures from 726° to 566°C
Authors: Matsumoto Yoshishige
Published: November 2005

Zn diffusion in GaAs and Al
x
Ga1-x
As (x≤0.4) was investigated at temperatures from 566° to 726°C, with 5/50/45 (Ga/As/Zn) and ZnAs2 sources. The time and temperature dependence of the diffusion depth in GaAs was obtained as d(µm)=4.55×106√t(h)exp
(-1.20e
V/k
T(K)) for a wide temperature range (566°–950°C). The activation energy E
c obtained from the temperature dependence of Zn concentration in the diffused layer was found to be 0.68 eV which agreed with calculations based on thermochemical analysis taking Ga self-diffusion into consideration. It was observed that X
j=d/√t in Al
x
Ga1-x
As monotonically increased with increasing x and that the activation energy of X
j for Al0.3Ga0.7As was 1.03 eV which was smaller than that of 1.20 eV in GaAs. The present results for Al
x
Ga1-x
As are explained by considering the increase in the lattice binding energy with Al content x, based on an I-S diffusion model of Zn.
Zinc Diffusion into InSb
Authors: Nishitani Kazuo , Nagahama Kouki , Murotani Toshio
Published: November 2005

A systematic study has been performed on diffusion of Zn in InSb using elemental Zn and Sb as the source in closed ampoules at 355–455°C. The diffusion behavior could be well understood by arranging the data as a function of the mole ratio of Sb to Zn in the source, N
Sb/N
Zn. The diffusion depth was constant and independent of the total amount of Zn and/or Sb when N
Sb/N
Zn≤0.5 or when N
Sb/N
Zn≥5, if the Zn source was enough. When N
Sb/N
Zn≥5, a highly planar, reproducible diffusion front was obtained. However, when N
Sb/N
Zn<5, a very ragged diffusion front and much damage were observed. These findings are understood using the In-Sb-Zn ternary phase diagram. Activation energies of 2.8 and 1.5 eV were obtained for N
Sb/N
Zn≤0.5 and N
Sb/N
Zn≥5, respectively, which suggests that there are two different diffusion mechanisms depending on N
Sb/N
Zn.
Fourier Analysis of the Wave Number of Unstable Waves in a Spiral Beam-Plasma System
Authors: Idehara Toshitaka , Usami Kunihiko
Published: November 2005

To analyze the wave number of unstable waves in a spiral beam-plasma system, the interferometer output of the propagating wave is Fourier-transformed. By using this method, the ratio between the amplitudes of elementary waves as well as their wave numbers are determined, even when three or more waves are included in the observed wave pattern. The instabilities caused by beam waves of higher order are identified from the comparison of the observed wave number with the theoretical dispersion relation.
Development of Microwave Undulator
Authors: Shintake Tsumoru , Huke Kazuo , Tanaka Jiro , Sato Isamu , Kumabe Isao
Published: November 2005

A microwave undulator which uses transverse fields of standing microwaves the been operated successfully at the Photon Factory electron linac. The undulator consists of a long rectangular cavity with two ridges. Using a pulsed S-band microwave of 300 kW and a pulsed electron beam, the undulator radiation was observed in the visible region, and the spectral intensities were measured. The equivalent magnetic field and the period are 430 Gauss and 5.5 cm, respectively.
A Novel Method of Stabilizing Frequency-Modulated Microwave for Coherent Transient Spectroscopy
Authors: Minowa Tatsuya , Matsuo Yukari , Kasuga Takashi , Shimizu Tadao
Published: November 2005

A method of stabilizing the microwave frequency modulated for the observation of transient molecular responses has been developed. Good long-term stability of the mean values of the modulated microwave frequencies is achieved; the stability is 3×10-9/day for an NEC 10V13 klystron and 10-8/day for OKI 24V11, 25V12, and 47V12 klystrons.
This stabilizer has operated successfully in measuring the relaxation rate constants of weak rotational transitions of OCS and HCOOH, whose absorption coefficients are in the region 10-6-10-7 cm-1.
P-n Junction Capacitance Thermometers
Authors: Katsuhata Makoto , Yamagata Shigeo , Miyayama Yoshiyuki , Hariu Takashi , Shibata Yukio
Published: November 2005

Silicon and germanium p-n junction capacitance thermometers making use of the temperature dependence of the junction capacitance were developed. At the temperatures at which the sensitivities are at a maximum, the specific sensitivities of the silicon and germanium capacitance thermometers are experimentally shown to be 0.34 and 1.74, respectively, at a measurement frequency of 1 kHz and are much greater than those of commercially-available strontium titanate glass-ceramic capacitance thermometers. According to the design principle shown here, a gallium arsenide p-n junction capacitance thermometer can measure a very low temperature down to about 2.8 K at a measurement frequency of 0.1 Hz.
Asymmetrical Lamb Dip in a High-Gain 3.5 µm Xenon Laser. I. Experiments
Authors: Asami Shigeo , Gamo Hideya , Tako Toshiharu
Published: November 2005

Deep and pronounced asymmetrical Lamb dips were observed in a single-mode oscillation with a 3.5 µm 136Xe laser over wide ranges of gas pressure (4.3–19.6 Pa) and dc excitation current (0.6–7 mA). The peak on the high-frequency side of the dip has a larger output power than that on the low-frequency side over wide ranges of gas pressure and discharge current. The asymmetry and depth of the dip, and the output power in the tuning curve were investigated with emphasis on their dependence on the xenon pressure and dc discharge current.
Temperature-Independent Photoluminescence in Amorphous Si1-xCx: (F, H) Films with Low Defect Density
Authors: Morimoto Akiharu , Miura Takashi , Kumeda Minoru , Shimizu Tatsuo
Published: November 2005

Photoluminescence and electron spin resonance measurements were carried out on amorphous silicon-carbon alloy film containing both F and H (a-Si1-xCx: (F, H)) prepared by the glow discharge decomposition of a mixture of SiH4and CF4gas. The a-Si1-xCx:(F, H) film, which had a wide optical gap (about 2.8 eV) had a smaller spin density and a photoluminescence with a higher intensity at room temperature and with a weaker temperature dependence than the a-Si1-xCx:H film with a similar optical gap. The temperature-independent photoluminescence appears to be due to an increase in the width of the band tail caused by the incorporation of F atoms.
Influence of Impurities on the Growth of Tin Whiskers
Authors: Kawanaka Ryusuke , Fujiwara Kenzo , Nango Shigeyuki , Hasegawa Tomoharu
Published: November 2005

Observations by micro Auger electron spectroscopy and X-ray micro analysis have been made on tin films electroplated on substrates of brass or zinc-coated copper, and on whiskers grown on the films. Direct experimental evidence has shown the existence of zinc and oxygen atoms on the surfaces both of the whiskers and the films. Copper atoms have also been detected in the whiskers and the films. A mechanism for the whisker growth is proposed, based on these experimental results. After electroplating, zinc atoms migrate onto the tin surface and bind there with oxygen atoms. At this stage, the nuclei of whiskers are formed, and the whiskers begin to grow with the aid of the internal stresses caused by the recrystallization of tin grains and/or the formation of intermetallic compounds of tin with copper.
Titanium Oxycarbide on TiC (100) Surface
Authors: Oshima Chuhei , Otani Shigeki , Aono Masakazu , Zaima Shigeaki , Shibata Yukio
Published: November 2005

Experimental data on chemical composition, atomic structure and electronic structure strongly suggests that titanium oxycarbide, TiOxC1-x, a mixed phase of TiO and TiC, is formed on the surface when a TiC (100) surface is exposed to oxygen and is then heated at ∼1000°C in an ultra-high vacuum.
Internal Stress in Evaporated Tellurium Films
Authors: Okuyama Katsuro
Published: November 2005

The internal stress and electrical resistivity were measured during and after deposition for tellurium films evaporated on a glass substrate. Both tensile and compressive stresses were observed depending on the substrate temperature during deposition. For the films deposited at room temperature, a tensile stress was generated accompanied by a drastic decrease in the resistivity. In contrast, a compressive stress was initially developed in the films deposited at 100°C and then the stress changed into the tensile one as the deposition progressed. The experimental results were interpreted in terms of the phase change mechanism and the lattice expansion and grain boundary annealing mechanisms, respectively.
Fabrication of NbN Films by dc Bias Sputtering and Their Application to Superconducting Bridges
Authors: Goto Toshinari , Anprung Prasan
Published: November 2005

NbN thin films have been prepared by double cathode dc reactive sputtering method. The effect of the substrate bias and the nitrogen partial pressure on the films' resistivity and superconducting transition temperature were investigated. A high critical temperature of around 16 K was obtained for 300 nm films made at about -80 V substrate bias voltage and suitable nitrogen partial pressure. The thickness dependence of the films' critical temperature was determined for film thickness down to 5 nm. NbN variable thickness bridges with length of about 0.2 µm were fabricated and shown to be feasible for use as Josephson devices. Microwave induced steps were observed over the bridges' I-V characteristics over rather narrow temperature ranges.
Defect-Free Reactive Ion Etching of Silicon by SiF4/Cl2 Plasma
Authors: Matsumoto Hiroshi , Sugano Takuo
Published: November 2005

Defect-free reactive ion etching (RIE) of silicon has been carried out using a mixture of SiF4 and Cl2 as the etching gas. The etching mechanism is investigated with a quadrupole mass spectrometer and the main reaction products are found to be Si2F6 or SiF3 for the Si etching and Si2F6O for the SiO2 etching. The deposition of (SiF2)
n
which occurs during the etching of silicon can be prevented by adding Cl2 gas to the SiF4.
A defect-free Si surface, characterized by deep-level transient spectroscopy (DLTS), is obtained by RIE using a mixture of SiF4 (70%) and Cl2 (30%) at a pressure of 7.0 Pa with an rf power density of 0.24 W/cm2.
Contactless Measurement of Photoinduced Carrier Lifetime and Injection Level in Silicon Wafer Using Additional Eddy Current
Authors: Maekawa Takao , Inoue Shozo , Usami Akira
Published: November 2005

A new contactless method for measuring the lifetime and the injection level of photoinduced excess carriers in silicon wafer is described. In order to flow measuring current in the wafer, a pair of high frequency magnetic fluxes in opposite directions are used so as to concentrate the induced eddy current in the central part even for narrow wafer. The voltage in the wafer caused by eddy current and the photoconductivity are analyzed, and it is shown that the injection level of excess carriers can be calculated from the relation between the above voltage and lifetime measured for the different illumination intensity. The dependence of lifetime on the injection level for NTD Si and normally doped n-C.Z Si wafers are found to be considerably different. The measurement sensitivity and the spatial resolution of this method are discussed.
Equilibrium Bunch Length of Beam Current in Electron Storage Rings
Authors: Miyahara Yoshikazu
Published: November 2005

A simple formalism for bunch lengthening in electron storage rings is given as an equilibrium state of the electron distribution in the longitudinal phase space, which is determined by the balance of quantum excitation, radiation damping, longitudinal coherent instability and Landau damping of the instability. The parameter dependence of the bunch lengthening is compared with other formulas. A numerical application of the new formula is given for several electron storage rings.
ESR Study on Radical Existing in Plasma-Polymerized Styrene Thin Film
Authors: Ohno Keiichi , Ishii Nobuyuki , Sohma Junkichi
Published: November 2005

The residual radicals formed in plasma-polymerized styrene (PPS) thin films are investigated by ESR measurement. An asymmetric singlet line characteristic of oxide radicals with an-isotropic g-values (g
1=2.008, g
2=2.006, and g
3=1.993) is observed in PPS produced under oxygen carrier gas, whereas a symmetric line is observed in PPS produced under nitrogen carrier gas, as previously reported. Castner's and Korb and Maruani's methods are used to extract the unresolved inhomogeneous and homogeneous broadenings Δ
H
G and Δ
H
L, from which the spin-relaxation times T
1 and T
2 are obtained. In the case of the PPS with nitrogen carriers, the introduction of air accelerates the decrease in the concentration of radical ions and Δ
H
G, while it keeps Δ
H
L constant. The opposite variations in T
1 and T
2 mean that no annealing effect appear explicitly up to 100°C. At temperatures higher than 100°C, the increase in T
2 due to the decrease in the concentration of radicals makes the experimentally-recorded linewidth Δ
H
msl narrower.
Detection of Neutral Species in Silane Plasma Using Coherent Anti-Stokes Raman Spectroscopy
Authors: Hata Nobuhiro , Matsuda Akihisa , Tanaka Kazunobu , Kajiyama Koichi , Moro Norio , Sajiki Kazuaki
Published: November 2005

Coherent Anti-Stokes Raman Spectroscopy (CARS) has been employed for the first time to investigate silane (SiH4) glow-discharge plasma. By measuring ν1 vibrational line of silane as a function of position between the two electrodes, spatial distribution of silane (number density) in the (bulk) plasma has been determined for various gas pressures. It has been demonstrated that CARS is an excellent diagnostic tool for a chemically-active plasma such as silane-based glow discharge.
Vibrations in Circular Ring Type Transducers
Authors: Sakuma Sadaomi , Shinada Toru , Ueha Sadayuki , Mori Eiji
Published: November 2005

To make clear the relations among the frequency spectra, the outer diameter to thickness ratio and vibration patterns in a circular ring type thick transducer, its frequency spectra and corresponding vibration velocity distributions are successfully measured with an electrical immittance measuring system and an optical heterodyne technique. The measurements are carried out reducing the outer diameter to a thickness ratio of from 20 to 2, where 4 transducers of Pb(Zr · Ti)O3 with different inner diameters (outer diameter, 82 mm; thickness, 4.15 mm) are used.
Composition and Chemical Bonds in Silicon Nitride by SiH4-N2 Gas Mixture Plasma CVD
Authors: Fujita Shizuo , Zhou Nan-Sheng , Sasaki Akio
Published: November 2005

Plasma CVD silicon nitride films are produced from SiH4–N2 gas mixture with a constant flow ratio SiH4/N2=0.1. When the pressure decreases and the substrate temperature increases, the Si/N composition approaches the stoichiometric value 0.75. As compared with the film deposited from SiH4–NH3 reaction, the present ammonia-free silicon nitride contains little N–H bonds and less hydrogen, and can be expected to have higher atom concentration and tight bondings.
Optical Waveguide in GaAs by Drive-in Diffusion Technique
Authors: Ohke Shigeaki , Ida Yasuhisa , Kusunoki Akira , Cho Yoshio , Matsuo Yukito
Published: November 2005

This report describes a technique for forming a thin layer as an optical waveguide in GaAs by a diffusion process alone. The optical waveguide has been fabricated by drive-in diffusion technique using powder-like ZnAs2 as the predeposition source. Since low-surface hole concentration and abrupt step profile are obtained therewith, this technique promises the possibility of forming low-loss waveguides for integrated optics through a comparatively simple process.
Etching Characteristics for Organosilica
Authors: Endo Nobuhiro , Matsui Shinji
Published: November 2005

Organosilica etching characteristics are described. The organosilica films are obtained by spin-coating, followed by baking at less than 200°C temperatures. The wet chemical etch rate for organosilica is 200 times faster than that for thermally grown SiO2. The etch rate, including the physical sputter effect in a plasma, is a little more than twice that. The organosilica etch rate ratios to organic resist materials show an accurate pattern transfer for reactive sputter etching. The organosilica is also applicable to the intermediate layer in the tri-level resist process.
Glow-Discharge Deposition of a-Si: H from Pure Si2H6 and Pure SiH4
Authors: Matsuda Akihisa , Kaga Takao , Tanaka Hideo , Malhotra Lalit , Tanaka Kazunobu
Published: November 2005

Optical emission spectroscopy and mass spectrometry have been employed as diagnostic tools for studying the glow discharge plasma of pure SiH4 and pure Si2H6. It has been suggested that the dimeric species play an important role in the deposition of a-Si: H from Si2H6 glow discharge in contrast to the monomeric species of SiH dominant in the deposition from pure SiH4. A large amount of hydrogen which is not bonded with Si is incorporated in a-Si: H films prepared from Si2H6 and this might be reflected in the dark and photoconductivity of the films.
Effect of H2 on the Quality of Si-Doped AlxGa1-xAs Grown by MBE
Authors: Kondo Kazuhiro , Muto Shunichi , Nanbu Kazuo , Ishikawa Tomonori , Hiyamizu Satoshi , Hashimoto Hisao
Published: November 2005

Dry H2 gas (5×10-8∼2.4×10-6 Torr) was introduced during MBE growth of Al
x
Ga1-x
As (x∼0.2) at a substrate temperature of 680°C. Photoluminescence intensity was dramatically improved by a factor of 7 with the introduction of a small amount of H2 gas of 5×10-8∼5×10-7 Torr. The DLTS signal (0.6 eV below conduction band edge) decreased with the introduction of H2.
Ablative Acceleration of Pellet Shells Irradiated by External Soft X-ray Sources
Authors: Mochizuki Takayasu , Sakabe Shuji , Okada Kazuyuki , Shiraga Hiroyuki , Yabe Takashi , Yamanaka Chiyoe
Published: November 2005

The first direct experimental measurement of soft X-ray driven ablation pressure has been done using a spherical pellet target and external soft X-ray sources. It has been found that the pressure is about 10 Mbar at an incident X-ray intensity I
x of 1013 W/cm2 for glass and CH targets, and its intensity scaling is I
x
0.8. X-ray backlighted pellet images indicate that X-ray geometrical smoothing at indirect irradiation is very effective for symmetrizing the implosion.