bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Observation of the Thermal Desorption of Oxygen from the Surface of β-Copperphthalocyanine by X-Ray Photoelectron Spectroscopy
Authors: Mizuguchi Jin
Published: November 2005

Thermal desorption of oxygen from the surface of β-copperphthalocyanine has been investigated in the temperature range of room temperature to 200°C by X-Ray Photoelectron Spectroscopy. The Ols peak due to adsorbed oxygen began to decrease at about 90°C and decreased further as the temperature increased. This direct observation of the thermal desorption supports the photocurrent-quenching model, in which the thermal quenching is caused by thermal desorption of ionosorbed oxygen in the form of O-
2 which has created an electrostatic field necessary for exciton dissociation into free electrons and holes.
Electroluminescenee in Polyethylene Terephthalate (PET) I. Impulse Voltage
Authors: Kojima Kenzo , Takai Yoshiaki , Ieda Masayuki
Published: November 2005

Electroluminescence was observed in PET when an impulse voltage was applied. The electroluminescence depended on the electrode material of the cathode and showed only a weak temperature dependence and a superlinear dependence on the electric field. The spectrum of the electroluminescence was identical with that of the photoluminescence originating from PET molecules. Considering these results, the following mechanism was concluded to be responsible for the electroluminescence in PET. Electrons injected from the cathode by tunneling through the interfacial barrier are accelerated by the electric field to sufficiently high energy to excite or ionize PET molecules. They finally lose their energy and become trapped, forming a space charge layer. The electroluminescence occurs when the excited PET molecules are deactivated into their ground states. The generation and dissipation of the space charge is discussed in this paper, and analysis of the electroluminescence is shown to be useful for understanding the dynamic behavior of the space charge in polymers.
Far-Infrared Magneto-Optical Study of Photoexcited Indium Antimonide. I. General Characteristics
Authors: Ohyama Tyuzi , Fujii Ken-ichi , Otsuka Eizo
Published: November 2005

Time-resolved far-infrared cyclotron resonance was carried out at liquid helium temperatures for both n- and p-type InSb under intrinsic photoexcitation. The optically hot nature shows up very clearly for the photoelectron system. Detailed electron temperature analysis was carried out on a p-type sample, using the intensity ratio of the two lowest cyclotron transition signals. The electron temperature was found to decrease from 40 K at a time constant of 6.5 µs. Joint observation of electron and hole signals at four different wavelengths enabled us, using the calculation by Pidgeon and Brown, to modify the values of the Luttinger parameters of the valence band. Cyclotron emission similar to that detected under electrical excitation was observed in an n-type sample.
Measurement of Surface Patterns by Using Interference of Diffraeted Laser Beam
Authors: Wada Takashi , Hattori Hajime , Umeno Masayoshi
Published: November 2005

This parer describes an optical contour method of displaying a surface by interference between two laser beams; one reflected by a grating placed over a test surface without contact and the other transmitted through the grating and reflected by the test surface. An optical filtering technique was applied to vary the measuring sensitivity by selecting the diffraction order, from several micrometers to several tens of micrometers. Discussions on the surface conditions of samples and the grating profiles needed to obtain clear contour fringes are presented. This technique can be applied to the study of the fracture toughness of metals.
Oscillation in Semiconductors with a Dumbbell-Shaped Structure
Authors: Kuwano Hiroshi , Into Jun-ichi , Endo Katsumi
Published: November 2005

A new model of current oscillation observed in the current saturation regime of the current-voltage characteristic in semiconductors with a dumbbell-shaped structure is proposed. As the electron and hole drift velocities deviate from Ohm's law, an electric double layer is formed on the anode side of the narrow region of a sample and a negative resistance region appears on the cathode side. These formations in the sample cause the current oscillation. Experimental measurements of the potential distributions in the sample are carried out for n-type germanium and it is shown that these results can be explained well by the proposed model.
Onset of Current-Driven Turbulence on Application of a Low Toroidal Electric Field
Authors: Nakamura Yukio , Watanabe Takechiyo , Nagao Akihiro , Nakamura Kazuo , Hiraki Naoji , Itoh Satoshi
Published: November 2005

The critical condition for current-driven instability excited in a turbulently-heated TRIAM-1 tokamak plasma is investigated experimentally. A resistive hump in the loop voltage, plasma density fluctuation and rapid increase in electron temperature in the skin layer are simultaneously observed when the electron drift velocity equals the critical drift velocity for low-frequency ion acoustic instability.
Measurement of the Resistance of Manganin under Liquid Pressure to 100 kbar and Its Application to the Measurement of the Transition Pressures of Bi and Sn
Authors: Nomura Motoyuki , Nishizaka Teiichirou , Hirata Yasushi , Nakagiri Nobuyuki , Fujiwara Hiroshi
Published: November 2005

The electrical resistance of manganin wire and the X-ray diffraction of NaCl were measured simultaneously under hydrostatic pressures up to 100 kbar using a cubic-anvil type pressure apparatus at room temperature. The solidification pressures of 1: 1 pentane-isopentane and isopropanol were determined by taking advantage of the sensitivities of the resistance of manganin wire to the local stress. The transition pressures for BiIII↔V and SnI↔II were measured in both loading and unloading by detecting the pressure where the high-pressure phase and the low-pressure phase coexist.
Automatic Electrical Measurement of Contact Pressure Distribution of a Spherical Wheel Running on Soft Powdery Ground
Authors: Takahashi Kiyoshi , Nakai Kazunari , Fujimori Hiroyoshi
Published: November 2005

A spherical wheel was pulled and driven on soft ground and the contact pressure between the tread and the ground was measured with several small pressure sensors attached to the circumference of the wheel. The height and width of the pressure distribution curves along the contact surface of the wheel increased when the wheel load increased. From the contact pressure distribution curves, it was confirmed that the rolling resistance of the spherical wheel rolling on soft ground could be approximated by that of a set of cylindrical wheels with different radii.
An AlGaAs/GaAs Concentrator Solar Cell Operating at High Concentration Ratios without Forced Cooling
Authors: Mitsui Kotaro , Yoshida Susumu , Yoshida Masahiro , Oda Takao , Yukimoto Yoshinori
Published: November 2005

A 1×1 cm2 p-AlGaAs/p-GaAs/n-GaAs concentrator solar cell operating at high concentration ratios without forced cooling is described. The cell has a fairly large junction depth (the thickness of the p-GaAs layer) of 3 µm which reduces the sheet resistance of the surface layer and permits the use of a relatively crude contact grid pattern which is easily fabricated. The cell has its highest fill factor of 0.889 at 50–100 suns and its highest efficiency of 22.7% at 50–200 suns, and also maintains a practical efficiency of 17.6% even at 1025 suns without forced cooling.
Evaluation of Activation Energies for Polarization in Glass from Thermally-Stimulated Depolarization Currents
Authors: Doi Akira
Published: November 2005

The partial discharge technique was applied to the conduction polarization peak of the thermally-stimulated depolarization current in lithium disilicate glass. It was concluded that the technique could not give reliable values for the activation energy for polarization, although it was proposed as one of several techniques for determining the distribution of the activation energy as well as for separating overlapping peaks.
Redistrubution of Zn Implanted into GaAs
Authors: Kasahara Jiro , Sakurai Hiroshi , Kato Yoji , Watanabe Naozo
Published: November 2005

The depth distribution of Zn implanted into GaAs was measured using secondary ion mass spectrometry (SIMS). Hole concentration profiles agreed well with atomic concentration profiles at the optimum annealing temperature of around 700°C. Electrical activity of the implanted Zn was over 90% taking into account the out-diffusion of Zn. Implanted Zn atoms were redistributed during capless annealing and piled up at a depth of about R
p+1.5ΔR
p. Rutherford backscattering measurements indicated that the pileup occurred near the interface between the amorphous layer induced by high dose ion implantation and the single crystal.
A Backscattering-Channeling Study of Thermally Grown Nitride Films on Silicon
Authors: Tatsuta Shigeru , Nishi Hidetoshi , Ito Takashi
Published: November 2005

The backscattering-channeling method using 330 keV He+ ions has been applied to a study of plasma-enhanced, thermally grown nitride films on (100) Si. The nitride films are stoichiometric Si3N4, and the interface is reconstructed with 10.5×1015 atoms/cm2 of silicon atoms, which corresponds to 3.9 atoms/string.
Glow Discharge a-Si1-xCx: H Films Studied by ESR and IR Measurements
Authors: Morimoto Akiharu , Miura Takashi , Kumeda Minoru , Shimizu Tatsuo
Published: November 2005

The results of ESR, IR and optical measurements on hydrogenated amorphous Si1-x
C
x
films prepared by glow discharge (GD a-Si1-x
C
x
: H) are presented. The spin density N
s increases drastically from 1016 cm-3 to 1020 cm-3 and the g-value gradually decreases from 2.0055 to 2.003, as the C content x is increased from 0 to 0.6. The weak dependence of g-value on x when x is less than 0.3 indicates that the increase in N
s with x is mainly due not to C dangling bonds but to Si dangling bonds in contrast with the results of previous studies on a-Si1-x
C
x
films prepared by CVD or rf sputtering.
Generation of Super-Fast Ions due to Nonlinear Processes near the Quarter Critical Density in Laser-Produced Plasmas
Authors: Yamada Kawakatsu , Sakabe Shuji , Miyanaga Noriaki , Inada Yoshifumi , Kato Yoshiaki , Mima Kunioki , Yamanaka Chiyoe
Published: November 2005

The generation of super-fast ions (\gtrsimMeV) has been observed for the first time in a glass microballoon implosion experiment using a four beam glass laser Gekko IV to produce a surface irradiation intensity of 1013–1016 W/cm2. This is correlated with the appearance of filamentary structures in the spatial distribution of the 3ω0/2 emission, and is explained by the acceleration of super-hot electrons due to the ambipolar field. These super-hot electrons are produced in small scale filaments in the underdense plasma near the quarter critical density.
Electron Waves below the Electron Plasma Frequency without Boundary Effects
Authors: Ohnuma Toshiro , Watanabe Tsuguhiro , Sanuki Heiji
Published: November 2005

The propagation of an oblique electron thermal mode without boundary effects below the electron plasma frequency is confirmed experimentally and theoretically in a magnetized plasma using ray velocity surfaces. Furthermore, the refractive effects of the mode in an inhomogeneous medium are investigated.
Field-Emission Liquid Aluminum Ion Source
Authors: Torii Yasuhiro , Yamada Hiroshi
Published: November 2005

A field-emission liquid Al ion source with V, Ti, Mo and Re needle emitters has been built, and an Al ion beam obtained. Of the four types, the Ti and V emitters have continuously emitted Al ion beams for more than 0.5 and 2 hours, respectively. Basic emission characteristics such as source ion current, beam angular intensity, angular intensity distribution and emission current fluctuation have been measured for the source with the V emitter. The results obtained indicate the possibility of a very large emission current of more than 500 µA as well as compatible performance with other liquid metal ion sources. Beam angular intensities of 20–40 µA/sr were obtained at source ion currents 10–20 µA, and the maximum value observed was 380 µA/sr at 900 µA.
1.5 µm Wavelength InGaAsP/InP DH LED with Improved Radiance Characteristics
Authors: Wada Osamu , Sanada Tatsuyuki , Nishitani Yorimitsu , Sakurai Teruo
Published: November 2005

The effect of the composition of the carrier-confining layer on the radiance performance of an InGaAsP/InP DH LED at a wavelength of 1.5 µm was investigated. From precision spectrum measurements, the confining layer grown by conventional liquid phase epitaxy was found to allow electrons in the active layer to leak over the heterobarrier into the confining layer. This problem was eliminated by introducing an InP confining layer grown by a new technique, in which a reduced temperature and a thick melt were used. More than 50% improvement of radiance was realized and power coupled into a 50 µm core, 0.2 NA, graded index fiber in excess of 20 µW was achieved at 100 mA.
The Photovoltaic Observation of a Non-Conductive Layer due to BN Formed in a Boron Implanted Si Junction
Authors: Munakata Chusuke , Yagi Kunihiro
Published: November 2005

An improved flying-spot scanning method using a chopped photon beam was applied to a boron implanted Si p-n junction 76 mm in diameter. In a small area of the junction, the ac photovoltage was 30% lower than that of the remaining area thus showing a clear contrast in the flying-spot scanning image. From studies of the frequency dependence of the photovoltage and measurements using a four-point probe, it was concluded that the peculiar layer was covered with a non-conductive layer. The electron beam diffration method showed this layer to be boron nitride (BN).
I. D. Sawing of Silicon Crystal in Different Lubricant Environments
Authors: Kuan T. S. , Shih K. K. , Vechten J. A. Van , Baum T. , Westdorp W. A.
Published: November 2005

The chemomechanical effect of lubricant environments on the I.D. sawing induced surface damage in Si crystal was tested in water and in an aqueous solution of a commercial coolant by applying different potentials on the Si crystal. Variations in thicknesses and surface morphologies of Si wafers sawn in different environments suggested smaller saw blade vibration in the coolant than in water. The density of sawing induced defects and the thickness of the damaged surface layer are also less when sawing is done in the coolant. The application of negative potential on Si crystal during the sawing was found to produce less surface damage than the application of positive potential. These results indicated that the fracture behavior and/or the frictional property of Si surface are environment-sensitive.
Evaluation of Minority-Carrier Traps at the Interface in MOS Structures by Optical DLTS
Authors: Tokuda Yutaka , Usami Akira
Published: November 2005

A method is presented for determining the interface-state distribution in the half of the band gap adjacent to the minority-carrier band in MOS structures. Deep-level transient spectroscopy (DLTS) for MOS capacitors was performed under pulsed light illumination with a photon energy above the band gap energy (optical DLTS). Minority carriers are captured at the interface states during the light pulse and thermally emitted after the end of the light pulse. Experimental results are given for both hole and electron traps at the nSi–SiO2 interface.
Reactive Ion Beam Etching of GaAs in CCl4
Authors: Powell R. A.
Published: November 2005

Dry etching of GaAs using reactive ion beams (RIBE) derived from CCl4 is reported. Etch rates as high as 7800 Å/min-mA/cm2, ∼2.5× greater than with Ar+ sputtering, were obtained for 750-eV reactive ion energy. Etch profiles resulting from RIBE with CCl4 or inert Ar+-milling exhibited similar “overcutting,” i.e., sidewalls sloped away from the photoresist mask at ∼16° to the incident beam. Wall angle was independent of ion source-to-sample separation (15–22 cm) and substrate orientation (<100> or <111>-oriented GaAs), but was affected by tilting the substrate with respect to the incident ion beam.
NMR and IR Studies on Hydrogenated Amorphous Si1-xCx Films
Authors: Nakazawa Kenji , Ueda Shoichi , Kumeda Minoru , Morimoto Akiharu , Shimizu Tatsuo
Published: November 2005

NMR and IR studies have been carried out on glow-discharge-deposited a-Si1-x
C
x
:H films. The hydrogen content increases with an increase in x up to 0.4 mainly in gathered form contributing to the broad component of the NMR line. By combining the NMR and IR results, the proportionality between the number of H bonded to C and the intensity of IR absorption due to the C–H stretching mode vibration is ascertained. The proportionality constant is found to be A
str
C–H=1.7×1021 cm-2.
Study of the Temperature Dependence of the Magnetization Direction in Cobalt Single Crystals by 1 MV Lorentz Electron Microscopy
Authors: Watanabe Denjiro , Sekiguchi Takashi , Tanaka Toshiro , Wakiyama Tokuo , Takahashi Minoru
Published: November 2005

The changes in domain structures of h.c.p. cobalt single crystals of (112̄0) and (101̄0) orientations with temperature in the range 20–380°C have been studied dynamically in a 1000 kV electron microscope and recorded on the VTR. The results show unambiguously that the easy direction of magnetization in the domain rotates from the c-axis to a direction in the c-plane and vice versa with increasing and decreasing temperature in the range 200–330°C. The temperature dependence of the angle of rotation from the c-axis measured on the images agrees well with that calculated from the known anisotropy data.
Vapor Deposition of Diamond Particles from Methane
Authors: Matsumoto Seiichiro , Sato Yoichiro , Kamo Mutsukazu , Setaka Nobuo
Published: November 2005

Microcrystalline diamond has been formed on silicon or molybdenum substrates by vapor deposition from a geseous mixture of methane and hydrogen. Cubo-octahedral or multiply-twinned crystals were obtained. The structure of the deposits was identified by electron diffraction and Raman scattering.
Enhancement of Surface Plasmon excitation by Low-Energy Electron due to Surface Resonance on Si (001)–2×1
Authors: Horioka Keiji , Iwasaki Hiroshi , Ichimiya Ayahiko , Maruno Shigemitsu , Li Sung Te , Nakamura Shogo
Published: November 2005

ILEED measurements by electron energy analyser were performed to investigate the diffraction effect on inelastic scattering related to surface and bulk plasmon excitations. The relation between elastic and inelastic I–V curves of the 00-beam is discussed. A kinematical two-step picture is suitable for Bragg peaks, and two peaks due to DL (Diffraction before Loss) and LD processes are observed equally. For fractional order peaks, dynamical consideration is required, and the transition probability is affected by the symmetry between the initial and final states. Enhancement of surface plasmon excitation due to surface resonance was observed.
Compression-Decompression Control of Burning Fusion Plasma to Suppress Thermal Instability
Authors: Okamoto Masao , Ohnishi Masami , Hirano Kei-ichi
Published: November 2005

A possible method for the control of burning plasmas in ignited tokamaks is presented. By applying small-scale major radius compression-decompression repeatedly to the plasma with feedback control, thermal instabilities can be suppressed and the plasma stays at the unstable ignition equilibrium point. The variation of the major radius Δ
R during the control scales as Δ
R/R≈-Δ
n/2n, where R is the major radius, n is the density and Δ
n is the change in density during control.
A High-Efficiency Polarizing Interferometer for Far-Infrared Spectroscopy
Authors: Yoshihara Kunio , Kitade Atsuo , Matsushita Tadashi
Published: November 2005

A new interferometer based on the principle of the Martin and Puplett polarizing interferometer was constructed for Fourier spectroscopy in the far-infrared region. In principle, all the radiation entering the interferometer can be utilized without loss and the bias level of the interferogram is reduced to zero. The figure of merit in the signal is estimated to be about 6 times greater than that of the standard Michelson interferometer using a dielectric film as the beam-splitter. The experimental results in the 10–70 cm-1 range are described.
Observation of Lattice Images for θ' Precipitates in Al–4% Cu Alloys
Authors: Sato Tatsuo , Takahashi Tsuneo , Tanaka Nobuo , Mihama Kazuhiro
Published: November 2005

The structures of the intermediate θ' phase in Al–4% Cu and Al–4% Cu–0.03% Sn alloys have been studied using the 200 lattice image technique. The lattice image shows a complicated spacing of white fringes with a two layer period trend in the matrix 200 lattice fringes. By analysing the optical transform of the micrograph, the contrast behavior is interpreted as the superposition of the lattice image of the precipitate θ' and the moiré pattern due to θ' and the matrix. For Al–4% Cu–0.03% Sn alloys, small circular regions of β–Sn are found at the edge of the precipitates θ', the orientation relation being (100)β-Sn//(111)α.
Performance of Inverted Structure Modulation Doped Schottky Barrier Field Effect Transistors
Authors: Thorne R. E. , Fischer R. , Su S. L. , Kopp W. , Drummond T. J. , Morkoç H.
Published: November 2005

Inverted structure (Al, Ga)As/GaAs modulation doped Schottky barrier FETs were fabricated. The structures from which the FETs were prepared were grown by molecular beam epitaxy. These FETs are easier to fabricate than normal MD FETs, because the rectifying metal contact is made to GaAs rather than to (Al, Ga)As. Having the GaAs on top of the (Al, Ga)As also makes these devices less susceptible to degradation. Although the device structure is not yet fully optimized, normalized transconductances of 70 mS/mm and excellent saturation characteristics have been obtained.
Characterization of Nonuniformity in Semi-Insulating LEC GaAs by Photoluminescence Spectroscopy
Authors: Tajima Michio
Published: November 2005

Nonuniform distributions of deep levels in semi-insulating (S.I.) LEC GaAs are investigated by photoluminescence measurements at 4.2 K. Two emission bands at 0.65 and 0.80 eV always appear in S.I. crystals. The intensity profile for the 0.65–eV band is U- or W-shaped along a wafer diameter, corresponding to the etch-pit-density (EPD) profile, while that for the 0.80–eV band shows an inverse profile with respect to the EPD profile. This profile is strong evidence for the idea that the 0.65–eV band is associated with the main electron trap (EL2) present in S.I. crystals. The origin of the 0.80–eV band is considered to be the microdefects generated dominantly in the low-dislocation-density region.
Direct Observations of the 500 MHz Q-Patterns from the 10 and 35 GHz SQUID's
Authors: Miki Yukinobu , Fuma Hiroo , Masumi Taizo
Published: November 2005

The 500 MHz Quantum Interference patterns (Q-patterns) beyond 100 MHz previously reported have been directly observed for the first time from 10 and 35 GHz Superconducting Quantum Interference Devices (SQUID's). The observation was made by improving the bandwidth of the detection circuits, which was supposed to be the cause of the previous limitation on Q-patterns from the 10 and 35 GHz SQUID's. An improved system including a 10 or 35 GHz SQUID has possible applications to the measurement of signals due to even faster magnetic flux changes.
Effect of Substrate Surface State on Homogeneity of Compensation Temperature through Film Thickness in GdCo Films
Authors: Tanaka Hiroyuki , Katoh Toshiaki , Yoshino Seiji , Masuda Morio
Published: November 2005

How the compensation temperature in amorphous GdCo films varies with film thickness during deposition is examined in this work. Several GdCo layers, each 300Å in thickness, were successively deposited by rf sputter on glass substrates whose surfaces were cleaned with different procedures. The compensation temperature was determined from the temperature dependence of the transverse Hall effect after each deposition, and it was plotted as a function of the film thickness. Results show that the surface state of substrates remarkably influences the variation of the compensation temperature with film thickness during deposition.
Poling Effects on Anisotropic Temperature Changes in NMR Second Moments of Drawn PVDF Films
Authors: Ishii Fumiaki , Sawatari Takanori , Odajima Akira
Published: November 2005

For the drawn PVDF film, the NMR second moment vs temperature curves at 0° and 90° of the alignment angle (γ) cross over each other during the motional narrowing in the T
g rgion (∼-50^°C). On poling, however, they decrease almost in parallel up to -20^°C and show another narrowing above 30°C depending strongly on γ. These findings indicate that the molecular chain is oriented in the non-crystalline region and the poling more clearly separates low orientations from high orientations. The increase in the high orientation part should be attributed to polarization in the oriented non-crystalline region.
Space-Resolved Measurement of Electron Density by Neutral Li Beam Probing in NBT
Authors: Kadota Kiyoshi , Matsunaga Kouzi , Iguchi Harukazu , Fujiwara Masami , Tsuchida Kazuki , Fujita Junji
Published: November 2005

The spatial profiles of electron density in Nagoya Bumpy Torus (NBT) have been measured with a fast neutral Li beam probing, which utilizes the photon emission due to the electron impact excitation of the injected atoms. It is shown that plasmas are well contained inside the hot electron annuli. The attenuation of thermally injected Li atoms has been measured for the estimation of electron density as a cross check.
Determination of Tilt Bias Angles in Nematic Liquid Crystal Cells by Observing Angular Dependence of Rayleigh Line Intensity
Authors: Akiyama Ryuichi , Abe Shigeharu , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

Intensity contours of the Rayleigh scatteering, I
(E, E), I
(E, O) and I
(O, E), have been numerically calculated and graphically plotted as a function of θ and φ which specify the optic axis. Here the two superscipts of I represent the states of polarization, ordinary (O) or extraordinary (E), of the incident and scattered lights, respectively. There exist three points and one line where I becomes zero: I
(E, E)=0 for (θ=90^° , φ=α/2) and φ=α/2±90^°; I
(E, O)=0 for (θ=90^° , φ=0^°); and I
(O, E)=0 for (θ=90^° , φ=α). We have experimentally demonstrated that these zero points and line can be used to determine the optic axis within a few minutes and hence the so-called “tilt bias angle γ” within an accuracy of about ±0.1^°, unless γ is close to 45°.
Carbon Needle Emitter for Boron and Aluminum Ion Liquid-Metal-Ion Sources
Authors: Ishitani Tohru , Shimase Akira , Tamura Hifumi
Published: November 2005

A long-life glassy carbon needle emitter for a boron liquid-metal-ion source utilizing NiB alloy is developed. A lifetime (i.e. 50–90 hours) is achieved. The nickel coated carbon emitter is found also to be useful with an aluminum liquid-ion source.
Electron Spin Resonance of Petrified Woods for Geological Age Assessment
Authors: Ikeya Motoji
Published: November 2005

Electron spin resonance (ESR) spectra of both organic and inorganic radicals in petrified woods have been studied for the assessment of age and burial condition. Young woods contain lignin radicals that produce a signal with a width of about 7 G at g=2.0036. Radical spectra of acetic acid (CH2COOH·) and of methyl (CH3·) with hyperfine structures were observed for petrified woods of the Miocene epoch. ESR signal at g=2.0025 similar to coal was observed for the black carbonated portion. The spectrum, similar to that of natural quartz, was observed for silicated petrified woods older than Miocene. It is concluded that a rough age estimation of petrified wood can be made with ESR.
Theoretical Analysis of Frequency Characteristics of Photoacoustic Signal in Liquids
Authors: Kitamori Takehiko , Sawada Tsuguo
Published: November 2005

A Photoacoustic signal as a function of a light modulation frequency is analysed with use of a Fourier transformation and Green's function. The incident laser beam is assumed to be modulated in a δ-function series and to have a Gaussian distribution. The calculated result has a monotonous decrease with increasing frequency under 10 kHz and a resonance peak in the 100 kHz region. It is found that these are caused by decreased photoenergy with increasing frequency and the laser beam profile in the liquids. These results agree well with experimental results found under the same conditions.
Mechanical Properties of Heat-treated CZ–Si Wafers from Brittle to Ductile Temperature Range
Authors: Yasutake Kiyoshi , Murakami Junichi , Umeno Masataka , Kawabe Hideaki
Published: November 2005

Four point bending tests were performed on heat-treated CZ–Si wafers at various temperatures. The fracture stress at room temperature does not change with heat treatments if the wafer has surface-denuded zones. However, the yield stresses of wafers at 700°C are remarkebly lowered by such treatments. The heat-treated CZ wafers are deformed plastically at relatively low temperatures and deformation twins appear in such low temperature plastic deformation. Their appearance is closely related to deformation temperature, strain rate and the presence of the thermally induced defects.
Photoluminescence Intensity in InGaAsP/InP Double-Heterostructures
Authors: Yamaguchi Akio , Komiya Satoshi , Umebu Itsuo , Wada Osamu , Akita Kenzo
Published: November 2005

Photoluminescence (PL) intensity in InGaAsP/InP double-heterostructures is studied as a function of the excitation level in connection with the output optical power of the InGaAsP/InP light emitting diode (LED) at a high injection level. At excitation levels higher than 1000 W/cm2, the PL intensity is directly proportional to the output optical power of the LED at 8000 A/cm2, whereas at excitation levels lower than 100 W/cm2, there is no such correlation. The output optical power of an LED can be predicted prior to fabrication by the PL intensity in the material at an excitation level comparable to the current injection level in the operating LED.
Zero Temperature Coefficient Surface-Acoustic-Wave Delay Lines on AlN/Al2O3
Authors: Sugai Kazuyoshi , Tsubouchi Kazuo , Mikoshiba Nobuo
Published: November 2005

We have investigated the temperature dependence of surface acoustic wave (SAW) delay time on AlN films grown by metalorganic chemical vapor deposition (MO–CVD) on the basal plane of sapphire (Al2O3). The temperature coefficient of delay for AlN/Al2O3 structures for SAW propagation along the [11̄00] Al2O3 direction decreased with increasing k
H, where k is the wave number and H is the thickness of AlN films. We have succeeded in realizing zero temperature coefficient SAW delay lines at a certain value of k
H.
A Multiple-Beam Michelson Interferometer for the Far Infrared
Authors: Yoshihara Kunio , Okada Katsuhiko , Kitade Atsuo
Published: November 2005

Multiple-beam interference occurs in the Michelson interferometer when a semi-transparent mirror is inserted between the radiation source and the beam-splitter. This phenomenon is analyzed in detail and method of reconstructing the spectrum from the interferogram obtained with such an interferometer is described. Reconstructed spectra using an electronic computer are in good agreement with the assumed original spectra.
Theoretical Studies of High-Pressure Effects on Optical Properties of Ruby
Authors: Ohnishi Shuhei , Sugano Satoru
Published: November 2005

The discrete variational (DV)–Xα method is applied to the calculation of energies, Δ
E
U and Δ
E
R, of the excitations from the t2g
3
4A2g ground state to the t2g
2 eg 4T2g and t2g
3
2Eg excited states, respectively, of an octahedral [CrO6]9- cluster under high pressure. The dependence of these energies upon the Cr–O distance, R, is found to be δ(lnΔ
E
U)/δ(lnR)=-4.5, and δ(lnΔ
E
R)/δ(lnR)=0.375. The latter dependence gives a good agreement with an empirical relation between the pressure and the spectral shift of the R emission line of ruby; this relation is used for the pressure calibration.
Scattering Tomography
Authors: Yoneda Yasuharu , Chikaura Yoshinori
Published: November 2005

An X-ray tomographic system is described for observing biological materials and for medical diagnosis. In this method scattered X-rays produce a tomographic image, expressing a certain relationship between the scattering point and the recording point, on a multi-color cathode-ray-tube (CRT). We call this method scattering tomography (ST). The apparatus consists of scanning mechanisms for the sample and an electron beam CRT, two circular slits, a solid state detector, pulse-height analysers and other necessary electronic circuits. The ST images are in many cases, completely different from those obtained using conventional radiography or computed tomography. The scattering tomogpraphy system provides a useful tool for medical diagnosis and for studying biological materials in which neither conventional radiography nor computed tomography would be helpful.
Tunable Subpicosecond Pulse Generation from 535 to 590 nm by a Hybridly Mode-Locked Dye Laser
Authors: Ishida Yuzo , Naganuma Kazunori , Yajima Tatsuo
Published: November 2005

Tunable subpicosecond pulses are stably generated in a new wavelength renge of 535-590 nm from a cw mode-locked dye laser system using rhodamine 110 and disodium fluorescein active dyes, employing combined passive and synchronous mode-locking. A minimum pulse width as short as 0.25 ps has been achieved around 560 nm. Streak camera observations of the temporal profiles are given for both hybrid and purely synchronous mode-locking.
Scattering of Low Energy Oxygen Ions from a Polycrystalline Palladium Surface
Authors: Saiki Koichiro , Tanaka Shoji
Published: November 2005

Relatively sharp peaks were observed in the spectrum of the oxygen ions (O+) backscattered from a palladium surface in the low energy range. The negative ions (O-) which were produced during a collision with the target atoms also showed a peak in their backscattered spectrum and their intensity was larger than that of the neon ions under the same condition. The scattered ion yield, its energy dependence and the angular distribution were different for both charged state oxygens. Origin of the sharp peaks and the difference in the features of the two charged state ions are discussed qualitatively.
Selective Removal of Iron Garnet Film on Transparent Substrate by Laser Etching
Authors: Ando Koji , Tsukahara Sonoko
Published: November 2005

Iron garnet film on transparent substrate Gd3Ga5O12 immersed in phosphoric acid was etched by the irradiation of an Ar ion laser beam. Localized etching of the film occurred in the irradiated region, and the etching terminated when the thickness of the film became zero. Laser etching is expected to be an useful fabrication technique for garnet devices.
Role of Hydrogen and Fluorine in Amorphous Silicon as Elucidated by NMR and ESR
Authors: Shimizu Tatsuo , Nakazawa Kenji , Kumeda Minoru , Ueda Shoichi
Published: November 2005

Results of NMR measurements on H and F have been compared with those of ESR, IR and photoconductivity measurements in various kinds of a-Si films. The density of dangling bonds is found to have a close correlation with the content of dispersed H atoms contributing to the narrow component of NMR spectra, indicating that dispersed H atoms mainly play a role in decreasing the density of dangling bonds. Gathered H and F atoms contributing to the broad component of NMR spectra appear to play a role in decreasing the mobility.
Extraction of Pulsed Ion Beams from an Anode Covered with Liquid Material
Authors: Kitamura Akira , Yano Syukuro
Published: November 2005

In order to extend the life of anodes of pulsed ion diodes by preventing severe damage on the conventional anodes, a trial was made to extract ions from a plasma created by surface flashover on the oil-covered anode. The diode with this anode worked well as a so-called pinched electron beam diode. Production of proton beams of 10 kA with energies of about 400 KeV was confirmed by measurements with biased ion collectors and those of prompt γ-rays from the reaction 19F(p, γα)16O. Substantial reduction of damage and substantial extension of the life of the anode disc were realized.
A Copper-Related Shallow Acceptor in Quenched Germanium
Authors: Kamiura Yōichi , Hashimoto Fumio , Sugiyama Hazime , Yoneyama Shin-ichiro
Published: November 2005

The temperature variation of hole density was measured in the range 5–200 K after successive annealings at 320°C. It was found that a shallow acceptor at E
v+9 meV disappears on annealing, being replaced by a just equal additional density of substitutional copper. This provides experimental proof that the shallow acceptor is a defect complex containing at least one copper atom.
A Reproducible LPE Growth of High-Quality In1-xGaxP1-yAsy Layers on GaAs by the Control of Phosphorus Vapor on the Substrate
Authors: Suzuki Akira , Murakami Takashi , Kuriyama Yoichi , Matsunami Hiroyuki
Published: November 2005

Lattice-matched LPE growth of In1-x
Ga
x
P1-y
As
y
layers on GaAs was carried out using a conventional slider boat system. High-quality epitaxial layers with smooth mirror surfaces were reproducibly obtained by the control of the diffusion of P vapor from the melt to the substrate and the reaction with the substrate at high temperatures before the growth. A very thin surface layer on the substrate which is formed by the reaction with P vapor seems to improve the affinity between the melt and the substrate as well as to relax internal stresses of the epitaxial layer caused by the lattice mismatch.
Diamagnetic Transition due to Proximity Effect in a Fine Multi-Filamentary Nb–Ti Superconductor
Authors: Oda Yasukage , Fujii Genshiro , Nagano Hiroshi
Published: November 2005

The diamagnetism of a fine multi-filamentary superconducting wire of Nb–Ti embedded in Cu is measured. The wire shows two abrupt increases in diamagnetism when the temperature is decreased. The first is due to the ordinary superconducting transition of Nb–Ti filaments, while the second is caused by the “transition” into a weakly-coupled superconducting state through the induced superconducting Cu.
Measurement of Plasma Waves by Fraunhofer Diffraction Method in Microwave Region
Authors: Sonoda Yoshito , Sakurai Akihisa , Muraoka Katsunori , Akazaki Masanori
Published: November 2005

The Fraunhofer diffraction method, proposed as a new means of measuring the plasma wave and/or turbulence, is verified in the microwave region by its application to the measurement of plasma waves in low-pressure d.c. discharge. The superiority of this technique over the conventional scattering and the significance of its application in the microwave region are also described.
Microwave Resonance Lines of 16O2 in Its Electronic Ground State (X 3Σg
-)
Authors: Endo Yasuki , Mizushima Masataka
Published: November 2005

Low intensity absorption lines of 16O2, in v=0 and v=1 states, are observed in the 119 and 60 GHz regions. New sets of values for the molecular parameters, including λ
DD
which has not been observed yet, are obtained.
Velocity-Modulation Transistor (VMT) –A New Field-Effect Transistor Concept
Authors: Sakaki Hiroyuki
Published: November 2005

Field-effect transistors of a completely new category are proposed and analysed, in which the conductivity modulation Δ
G by the gate voltage V
g is brought forth mainly through the V
g-dependence of electron mobility. Since the sheet concentration of electrons in such FETs need not be modulated, the switching speed of the device is expected to be free from the transit time limitation, reaching the range of subpicosecond. As a specific example, an FET with a dual-channel configuration is discussed.
New Phenomena in Grain Boundary Josephson Junction Networks of BaPb0.7Bi0.3O3 Films
Authors: Enomoto Youichi , Suzuki Minoru , Murakami Toshiaki , Inamura Takahiro
Published: November 2005

The grain boundaries of superconducting BaPb0.7Bi0.3O3 (BPB) sputtered thin films work as Josephson junctions and also form two-dimensional junction arrays. Each film was shaped into a cross-pattern, with a gate and control lines, crossing each other perpendicularly. When the control current exceeds a certain critical value, the I–V curve of the gate behaves in two different ways: (1) With W
g<W
c (gate and control line widths), Josephson current for the gate line shifts by 2n
Δ/e (n: integer); (2) With W
g>W
c, curves in voltage state are elongated through the V-axis into the opposite quadrant.
Experimental Observation of the Total Reflection by a Monodomain Cholesteric Liquid Crystal
Authors: Takezoe Hideo , Ouchi Yukio , Sugita Akio , Hara Masahiko , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

The reflection spectra from a monodomain cholesteric liquid crystal are measured for obliquely incident light. The first order reflection region is found to be divided into three regions at a large angle of incidence. The central region shows high reflectivity irrespective of incident polarization and is attributed to the total reflection. The total reflection peak is also observed between the second order reflection peaks even at a small angle of incidence. The reflection spectra are numerically computed by the 4×4 matrix method and are in good agreement with the experiments.
Formation and Ionization Potentials of Lead Clusters
Authors: Saito Yahachi , Yamauchi Kenzi , Mihama Kazuhiro , Noda Tamotsu
Published: November 2005

Clusters of lead atoms have been produced by an adiabatic expansion of the vapour in a high temperature crucible through a small hole into a vacuum. These clusters have been ionized by electron bombardment and analysed with a time-of-flight mass spectrometer. Clusters of up to ten atoms have been observed, and Pb7, with the highest intensity. The relative abundance of the clusters is higher at higher crucible temperatures and/or with larger hole diameters. Ionization potentials of the clusters of up to seven atoms have also been measured. The change in the ionization potentials shows the same trend as that in an effective work function of a continuum metal drop.
Precision Goniometer for Fine Adjustment in the Nanoradian Range
Authors: Tanaka Mitsuru , Nakayama Kan
Published: November 2005

A new type of goniometer for precise and smooth control in orientation of an object is designed and manufactured with several circular flexure hinges in a single block of material. The preformance of the new goniometer for fine adjustment and the stability against disturbing vibration of the base of building are experimentally checked, which has shown the feasibility of this type of goniometer for control in orientation as fine as several nanoradians.
Thermal Annealing of Amorphous V3Si Thin Films
Authors: Takenaka Hisataka , Michikami Osamu
Published: November 2005

Superconducting properties of films prepared by annealing of amorphous V–Si thin films were investigated. Superconducting transition temperatures, T
c, phases and lattice constants for the films have been determined as a function of annealing temperature. By annealing at 560°C for 1 h at 1.3×10-1 Pa, the amorphous phase starts to transform into an A15 single phase. Maximum T
c onsets for films annealed for 1 h at 1.3×10-1 Pa and 1.3×10-5 Pa reach 12.0 K and 16.0 K, respectively. The T
c markedly increases with a decrease in the amount of oxygen contained in the films.
Simplified Theory of Mode-Locking Process for Evaluating SHG Autocorrelation Pulse Width
Authors: Urisu Tsuneo , Mizushima Yoshihiko
Published: November 2005

The SHG autocorrelation profile function has been derived by utilizing a simplified model. The theory is based on a concept that the mode-locking proceeds in an assimilation of random wavepackets into a single coherent pulse. A diagram useful for pulse width determination by the SHG autocorrelation profile has been obtained. The derived autocorrelation function has well explained the experimental results in the wide range of mode-locking conditions.
Gap States Distribution of Undoped a-Si: H Determined with Phase-Shift Analysis of the Modulated Photocurrent
Authors: Oheda Hidetoshi , Yamasaki Satoshi , Yoshida Toshihiko , Matsuda Akihisa , Okushi Hideyo , Tanaka Kazunobu
Published: November 2005

In order to determine the energy distribution of localized states in the band gap of undoped hydrogenated amorphous silicon, the previously proposed method, i.e. the phase-shift analysis of the modulated photocurrent, is applied to this material. Obtained is the tail states distribution with a bump structure around 0.62 eV below the mobility edge of the conduction band.
Ferroelectric Copolymers of Vinylidenefluoride and Trifluoroethylene with a Large Electromechanical Coupling Factor
Authors: Ohigashi Hiroji , Koga Keiko
Published: November 2005

A large electromechanical coupling factor k
t of about 0.3 has been found in vinylidenefluoride and trifluoroethylene copolymers containing 70–80 mol% VDF. These copolymers exhibit clear ferroelectric behavior. The strong piezoelectricity and distinctive ferroelectricity are attributable to high crystallinity, strong preferred orientation, and reduced conformational defects in crystallites, which are induced by annealing and successive or simultaneous poling. The polarization is inferred to grow through rotation of the polar axis by nπ/3 about the molecular axis (c-axis) under an external electric field above the coercive field.
Quasi-Steady Population Inversions of He+ in a Freely Expanding Plasma
Authors: Hara Tamio , Ohgo Tadashi , Hamagaki Manabu , Dote Toshihiko
Published: November 2005

Possibilities of a HeII plasmadynamic recombination laser are experimentally investigated. It is confirmed by experimental results that large quasi-steady population inversions for i=3–4, i=3–5 and i=4–5 levels of HeII exist over 5 cm downstream of the orifice. The maximum population inversion for the transition 4–5 observed corresponds to the single-pass gain of 1.03. A comparison is made between experimental data and calculated results on the basis of the collisional-radiative model on populations of HeII levels.
Formation of Relativistic Electron Beam Rings in a Conducting Cavity
Authors: Mohri Akihiro , Narihara Kazumichi , Tomita Yukihiro , Tsuzuki Tetsuya , Hasegawa Mitsuru , Ukegawa Kenichiro , Miyake Shinichi
Published: November 2005

It was experimentally demonstrated that a relativistic electron beam ring of spheromak configuration is formed and stably kept in a conducting cavity of rectangular cross section by injecting a rotating electron beam through a hole of the cavity without the help of the external magnetic field for equilibrium.
Microwave Plasma CVD System for the Fabrication of Thin Solid Films
Authors: Kato Isamu , Wakana Shin-ichi , Hara Shinji , Kezuka Hiroshi
Published: November 2005

This study was concerned with the development of a process for the deposition of thin-films from a microwave plasma of semiconductor materials. A coaxial line type microwave CW discharge was used to create uniform plasmas and a-Si films were fabricated from Ar gas containing 10% SiH4. The X-ray diffraction patterns shown that the fabricated films, where the microwave power is large, are crystallized and the structure of the other films is amorphous.
Si and Sn Doping in AlxGa1-xAs Grown by MBE
Authors: Ishibashi Tadao , Tarucha Seigo , Okamoto Hiroshi
Published: November 2005

Electrical properties of Si and Sn doped Al
x
Ga1-x
As epitaxial films grown by MBE have been studied in the wide range of AlAs mole fraction. With a constant doping level, decrease in the carrier concentration was observed around the direct-indirect band crossover point, for Si-doped and Sn-doped Al
x
Ga1-x
As. Abrupt increase in donor ionization energy E
D occurred in Si-doped Al
x
Ga1-x
As films. These characteristics are similar to those reported for Te and Sn doped Al
x
Ga1-x
As grown by LPE.