bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Resolution Transmission Electron Microscopy of Long-Period Structures of Various Phases in a Bi-Sr-Cu-O System
Authors: Matsui Yoshio , Takekawa Shunji , Nozaki Hiroshi , Umezono Akihiro
Published: February 2005

Three nonsuperconducting phases (B to D) in a Bi-Sr-Cu-O system have long-period structures closely related to that of the superconducting phase A, Bi2Sr2CuO
y
. In phase B, the long periodicity is caused by the displacements of the (BiO)2 planes along the c axis. In both phases C and D, it is due to the formations of thin vertical planes of different local structures and compositions. These planes are straight and repeat regularly to form a commensurate long-period structure in phase C, while they repeat irregularly to form an incommensurate structure with wavy lattice planes in phase D.
Neutron Diffraction Study on the Crystal Orientation of Y-Ba-Cu-O Superconducting Material Aligned in the Magnetic Field
Authors: Morii Yukio , Funahashi Satoru , Ozawa Kunio , Okada Michiya , Matsumoto Toshimi , Aihara Katsuzo , Matsuda Shinpei
Published: February 2005

The preferred orientation of the YBa2Cu3O
x
crystallites aligned in the magnetic fields at room temperature was measured by means of the neutron diffraction technique. The higher the magnetic field, the better the crystal orientation. The FWHM of the Lorentzian function fitted to the preferred orientation of the [001] axis along the applied 7 T field was 16.86 deg. for the tetragonal phase and 13.10 deg. for the orthorhombic phase I of the material. The results suggest that the magnetic alignment technique could be used to increase the critical current density of the superconducting material.
Tc=113 K Bi-Based Superconductor Prepared by Doping Fluorine
Authors: Horiuchi Shigeo , Shoda Kaoru , Nozaki Hiroshi , Onoda Yoshito , Matsui Yoshio
Published: February 2005

A new method for preparing a Bi-based superconductor with T
c=113 K and T
c,end=106 K is reported. Starting powders including a small amount of fluoride are heated in air. The final heating temperature is 860°C, which is lower by about 20°C as compared to the case without doping fluorines. During the heating process most fluorines are released from the crystal, while the (243) phase increases in volume at the cost of the (232) phase. High-resolution transmission electron microscopy (HRTEM) reveals that a frequent intergrowth occurs in the crystal.
High-Tc Superconducting Bi-Pb-Sr-Ca-Cu-O Thin Films Prepared by Thermal Decomposition of Metallic Complex Salts
Authors: Maruyama Toshiro , Higashi Seiji
Published: February 2005

Superconducting Bi-Pb-Sr-Ca-Cu-O thin films of zero-resistivity temperature 101 K and critical current 152 A/cm2 (at 77 K) were synthesized on MgO (100) single-crystal substrates by thermal decomposition of metal naphthenates. During the temperature rise in annealing, there appeared a Bi2Sr2CuO
x
phase above ca. 750°C, a highly crystallized Bi2Sr2CaCu2O
x
phase above ca. 820°C and a highly crystallized Bi2Sr2CuO
x
phase above ca. 875°C. The annealing time in formation of the Bi2Sr2Ca2Cu3O
x
phase should not be too long because of the relatively large surface effects in heat treatment of thin films.
Preparation of Tl2Ca2Ba2Cu3Ox Superconducting Thin Films by DC Sputtering
Authors: Chang H. L. , Wang C. , Chu M. L. , Uen T. M. , Gou Y. S.
Published: February 2005

Thin films of the Tl-Ca-Ba-Cu-O system were prepared by a single-target dc sputtering system on YSZ substrates with postannealing. The effects of various annealing conditions on the films were studied. It was found that under suitable conditions, the Tl2Ca2Ba2Cu3O
x
thin films with a zero-resistance temperature of up to 97 K could be formed by sputtering from a target of the same composition. The X-ray diffraction patterns showed that the annealed films were preferentially c-axis oriented perpendicular to the substrates. It was also found that the films were highly resistant to n-butyl acetate, acetone and water.
As-Grown Superconductivity of BiSrCaCuO Thin Films Prepared by Magnetron Sputtering with Three Targets: Bi2+a(SrCa)2Cu3Ox, Bi2(SrCa)2+bCu3Ox and Bi2(SrCa)2Cu3+cOx (a=b=1, c=1.5)
Authors: Kojima Kazuyoshi , Kuroda Ken'ichi , Tanioku Masami , Hamanaka Koichi
Published: February 2005

Superconducting BiSrCaCuO thin films were grown on MgO(100) substrates by magnetron sputtering with three targets. In order to precisely control the chemical composition of the metal elements, these three targets were simultaneously discharged; the heated (650°C) substrate was rotated above these targets. The superconducting transition temperature (zero resistivity) was 75 K in the as-grown state for the optimized sample. From the X-ray diffraction, The c-axis of the film was highly oriented normal to the substrate. The surface of the film was much smoother than that of the film grown with a single target.
Optical Absorption Spectra in Cobalt-Substituted Epitaxial Magnetic Garnet Films Measured with Photothermal Deflection Spectroscopy
Authors: Yasuhiro Kazumichi , Sato Katsuaki , Tamanoi Ken , Shinagawa Kiminari , Saito Toshiaki , Tsushima Tachiro
Published: February 2005

Optical absorption spectra were measured at room temperature by means of photothermal deflection spectroscopy (PDS) in Co2+-substituted or Co3+-substituted magnetic garnet films prepared by liquid phase epitaxial technique. We compared the PDS results with theoretical absorption spectra calculated for Co2+ and Co3+ ions using the ligand-field theory. A satisfactory agreement has been obtained between the calculation and the observation especially for the case of Co2+-substituted films.
Effect of a Polyimide Coat on the Layer Structure in a Surface-Stabilized Ferroelectric Liquid Crystal Cell
Authors: Orihara Hiroshi , Suzuki Atsushi , Isyhibashi Yoshihiro , Gouhara Kazutoshi , Yamada Yuichiro , Yamamoto Norio
Published: February 2005

The effect of surface treatment in surface stabilized ferroelectric liquid crystal(SSFLC) cells on the smectic layer structure was studied by X-ray diffraction. The surfaces of glass plates were coated with polyimide to produce low- and high pretilt cells. Two different types of diffraction patterns were obtained at room temperature; a pair of peaks was observed both in the low-pretilt cell and the high-pretilt parallel cell, while a single peak was observed in the high pretilt antiparallel cell. The dependence of the diffraction pattern on the temperature was also studied, and thermal hysteresis of this pattern was found.
Pressure-Induced Squeezing Phenomenon in Uniaxially Compressed Glass
Authors: Tanaka Keiji
Published: February 2005

Deformations of chalcogenide and oxide glasses subjected to intense uniaxial compression have been studied. These glasses undergo pressure-induced coalescence after the bulks are fractured with crackinag. The pressurized glasses exhibit optical anisotropy at 1 atm. The squeezing phenomenon appears to be unique to glassy phases, the origin of which is attributable to plastic deformation.
Initial Stage of Growth of Ge on (100)Si by Gas Source Molecular Beam Epitaxy Using GeH4
Authors: Koide Yasuo , Zaima Shigeaki , Ohshima Naoki , Yasuda Yukio
Published: February 2005

The growth process in the initial stage of growth of Ge on (100)Si substrates by gas source molecular beam epitaxy using GeH4 has been investigated by in-situ reflection high-energy electron diffraction (RHEED) observation. It has been found that the growth mode is the Stranski-Krastanov type, and that the predominant facet of Ge islands is {811} planes at the first step of the island growth but changes to {311} planes with the growth.
In-Situ Observation of Moving Dislocations in KCl Crystal by Laser-Light Topography
Authors: Kataoka Toshihiko , Ohji Hiroshi , Morishita Hitoshi , Kishida Keizou , Azuma Kensaku , Yamada Tomoharu
Published: February 2005

Edge dislocations moving on slip planes in a KCl single crystal under an applied load were observed successfully by the 90°-angle light scattering method. The images of moving dislocations were taken by means of an optical microscope and a video camera, where a high-power Ar-ion laser (2 W for a wavelength of 514 nm) and an image intensifier were employed to intensify scattered light from the dislocations. The motion of dislocations was smooth and the average velocity was about 10-7 m/s in the present observation.
Substrate Temperature Dependence of Carbon Incorporation into GaAs Grown by MBE Using Triethylgallium and As4
Authors: Saito Junji , Ono Katsuji , Kondo Kazuo
Published: February 2005

We have studied the substrate temperature dependence of carbon incorporation into undoped GaAs epitaxial layers grown by molecular beam epitaxy using triethylgallium and arsenic (As4). In the temperature range from 430°C to 680°C, samples show p-type conductivity with carbon as the residual impurity, which is measured by secondary ion mass spectroscopy. The lowest values of carrier and carbon impurity concentration are obtained at 550°C. The mechanism of carbon incorporation into the GaAs epitaxial layers grown using TEG and As4 is discussed.
Enhanced Critical Magnetization Currents due to Electron Irradiation in High-Tc Oxide Superconductors
Authors: Kato Takahiko , Shiraishi Kensuke , Kuniya Jiro
Published: February 2005

Three kinds of high-T
c oxide superconductors were successively irradiated with 3 MeV electrons up to 1.0×1018 e/cm2 at about 370 K, and magnetization measurements were performed at 77 K in fields up to 10 kG. The critical current density in the field, estimated from the magnetization curves, was enhanced by the electron irradiation to 5.0×1017 e/cm2 in the melt-processed YBa2Cu3O7-x
and Tl2Ba2Ca2Cu3O
x
compounds. In the Bi1.4Pb0.6Sr2Ca2Cu3O
x
compound, the critical current density was expected to be increased by electron irradiation to a dose much less than 5.0×1017 e/cm2.
The Effect of Sintering Conditions on the Formation of the High-Tc Phase in the Bi-Sr-Ca-Cu-O System
Authors: Kobayashi Shigeki , Saito Yasuyoshi , Wada Shigetaka
Published: February 2005

The effect of heat schedule on the formation of high-T
c phase has been studied. The two-step pattern held at 880°C for 20 min and at 870°C for a long time was chosen as the optimum heat schedule. After 200 hours of treatment at 870°C, zero resistivity was attained at 104 K and the value of AC susceptibility at 4.2 K was as high as 86% of the complete diamagnetism. Preheating at the temperature range of partial melting enhanced the formation of the high-T
c phase due to the densification, texture formation and the nucleus formation of the high-T
c phase.
Periodicity Change in Structural Modulation in Bi2Sr2Ca1-yREyCu2O8+δ (RE=Y, Nd) System
Authors: Niu Hiromi , Fukushima Noburu , Takeno Shiro , Nakamura Shin-ichi , Ando Ken
Published: February 2005

Changes in structural modulation for the Bi2Sr2Ca1-y
RE
y
Cu2O8+δ system (RE=Y, Nd), accompanied with the transition from the superconductor to the antiferromagnetic insulator, were examined. In the Bi2Sr2Ca1-y
Y
y
Cu2O8+δ system, the modulation periodicity continuously decreased, from about 5.0 times to 4.0 times the length of the subcell along the b axis, with increasing Y content substituted. The modulation periodicity for Bi2Sr2NdCu2O8+δ was about 4.0 times the length of the subcell along the b axis, the same as in the Bi2Sr2YCu2O8+δ. This decrease in the modulation periodicity is attributed to the valence change of Y3+ for Ca2+.
Effect of Hole Density on Superconductivity in the Nd-Ce-Sr-Cu-O System
Authors: Kosuge Michikazu , Kurusu Kazuhiko
Published: February 2005

Superconductivity of a solid solution with the composition of (Nd0.8-x
Ce
x
Sr0.2)2CuO
y
was investigated. This phase is a prototype superconductor which has single-layered CuO square-pyramidal unit. A single-phased sample was obtained in a narrow range of Ce content, 0.0875≤x≤0.1500. Oxygen content and Ce valence were determined by two kinds of coulometric titration techniques. The results show that all samples have oxygen vacancies and that Ce is tetravalent. The critical temperature rises with an increase in hole density, which is determined by titration.
Charge State Density Profiling of EL2 Deep Donor in GaAs Using Selective Excitation Luminescence
Authors: Tajima Michio , Iino Takayuki
Published: February 2005

The distributions of both ionized and neutral states of the dominant midgap donor EL2 in undoped, liquid-encapsulated, Czochralski-grown GaAs have been investigated by selective excitation luminescence. The intensity variations of the 0.63 and 0.68 eV emission bands, excited selectively by the 1.46 and 0.94 eV light, reflect the distribution of the neutral and ionized states of the EL2 level, respectively, because the initial states of the excitation processes of the two bands are the neutral and ionized states. In an as-grown wafer, the U-shaped profile across a wafer diameter has been observed for both EL20 and EL2+ distributions, suggesting that the total EL2 distribution is not uniform, but U-shaped.
MOVPE Growth of Selectively Doped AlGaAs/GaAs Heterostructures with Tertiarybutylarsine
Authors: Tanaka Hitoshi , Kikkawa Toshihide , Kasai Kazumi , Komeno Junji
Published: February 2005

We have used tertiarybutylarsine (tBAs) as a source alternative to AsH3 in the metalorganic vapor phase epitaxy (MOVPE) of selectively doped AlGaAs/GaAs heterostructures. A sheet carrier concentration of 9.2×1011 cm-2 and an electron mobility of 52000 cm2·V-1·s-1 have been obtained at 77 K for a heterostructure with a 5 nm spacer layer. This is, to our knowledge, the first demonstrated fabrication of two-dimensional electron gas with an alternative As source.
The Effect of Pb Substitution on the Bi-Sr-Cu-O Superconductor
Authors: Takemura Yasuhiko , Hongo Masashi , Yamazaki Shumpei
Published: February 2005

The effect of the substitution of Pb for Bi was investigated for the Bi-Sr-Cu-O superconductor. It was shown that the substitution of Pb for Bi stabilized the Bi2Sr2CuO
y
-type structure even at high temperature. Furthermore, the Pb substitution resulted in the decrease in T
c. The metal-superconductor transition using cationic substitution in the Bi2Sr2CuO
y
-type compound was discussed.
Hydrogen Profiling of High Temperature Superconductors
Authors: Schölch H. P. , Weiser M. , Kalbitzer S. , Saemann-Ischenko G.
Published: February 2005

Hydrogen distributions of high temperature superconductor bulk and film material, YBaCuO and BiSrCaCuO, have been determined up to depths of 1 µm. In both annealed and non-annealed samples widely varying volume concentrations, from less than 0.1 up to more than 10 at.%, respectively, have been found. The preparation conditions of the films strongly influence the hydrogen content. Surprisingly, no correlation at all of hydrogen content with stoichiometry, structure and critical temperature is observed.
A New Series of Compounds in the T* Structure: La2-x-zLnzSrxCuO4-y (Ln=Eu, Gd, Tb and Dy)
Authors: Maeno Yoshiteru , Lichitenberg Frank , Williams Tim , Kappinski Janusz , Bednorz J. Georg
Published: February 2005

We report the synthesis of a new series of layered copper-oxide compounds La2-x-z
Ln
z
Sr
x
CuO4-y
(Ln=Eu, Gd, Tb and Dy), which are isostructural to the T*-phase of superconductive Nd-Ce-Sr-Cu-O. Annealing in high-pressure oxygen atmosphere improves the metallic conductivity of the samples. However, we have not been able to induce bulk superconductivity in these new compounds.
Effect of Calcination Temperature on Formation of a Bi, Pb-Sr-Ca-Cu-O Superconductor via the Sol-Gel Method
Authors: Tanaka Katsuhisa , Nozue Akiyoshi , Kamiya Kanichi
Published: February 2005

An oxide superconductor in the Bi, Pb-Sr-Ca-Cu-O system has been prepared by the sol-gel method, and the effect of calcination temperature on the formation of the high-T
c phase has been examined. Calcination at 830°C before the reheat treatment at 845°C is the most effective for the formation of the high-T
c phase, as revealed by X-ray diffraction analysis. From this fact, we conclude that the nucleation of the high-T
c phase is apt to take place at around 830°C. The T
c value of the specimen calcined at 830°C and reheated at 845°C for 24 h is 90 K.
Synthesis of a 110 K Superconducting Phase in the Bi-Sr-Ca-Cu-O System
Authors: Nakajima Masato , Kawarabuki Seiichi , Sasaki Tomoko , Nojiri Naohiro , Watanabe Yoshihisa , Ikeda Hiroshi , Yoshizaki Ryozo
Published: February 2005

We have prepared a 110 K superconducting phase as the dominant phase in the BiSrCaCu2O
x
ceramic by sintering at 865±5°C for 900 h in air. This superconductor has a resistance T
c of 109.3 K and a structure containing stacking faults, as suggested by the broadened X-ray diffraction pattern. The volume fraction of the 110 K phase is as large as 28% by dc susceptibility measurements.
Effects of He Ion Irradiation on Superconductivity of Bi-Sr-Ca-Cu-O Films
Authors: Aruga Takeo , Takamura Saburo , Hoshiya Taiji , Kobiyama Mamoru
Published: February 2005

The zero resistance transition temperatures T
c (R=0) decrease remarkably from 92 K to 62 K in a Bi-Sr-Ca-Cu-O film irradiated with 400 keV He ions to a dose of 1.1×1019/m2 at room temperature. Resistivities above transition temperatures increase with increasing the dose, while transition temperatures T
c (onset) are relatively unaffected by He ion irradiations. The decrease in the transition temperatures and the resistivity increase after low-temperature irradiations at 85 K are larger than those after room temperature irradiation.
Preparation of Superconducting Bi-Sr-Ca-Cu-O Fibers on MgO Substrates
Authors: Takemura Yasuhiko , Yamazaki Shumpei
Published: February 2005

Superconducting Bi-Sr-Ca-Cu-O fibers were prepared on MgO substrates. Fibers were grown from a Bi-Sr-Ca-Cu-O melt in narrow grooves of 20 microns in width, which were formed on MgO substrates by means of a laser etching technique. These fibers consisted of long (100–500 microns) crystals and showed zero resistance below 72 K.
Angle Phase Matching in Second Harmonic Generation from a Ferroelectric Liquid Crystal
Authors: Taguchi Ayumu , Ouchi Yukio , Takezoe Hideo , Fukuda Atsuo
Published: February 2005

Phase matched second harmonic generation was observed in a ferroelectric liquid crystal mixture. An electric field was applied parallel to glass plates of a homeotropically aligned cell in order to introduce a uniform alignment of the directors and the permanent dipoles. The phase matching was performed with an extraordinary polarized incident light by rotating the cell around the direction of the electric field.
Elastic Recoil Detection Analysis of Hydrogen Content in Hydrogenated Amorphous Silicon Fims
Authors: Kudo Hiroshi , Kawazu Yunosuke , Miura Akira , Arai Toshihiro
Published: February 2005

By using Rutherford elastic recoil induced by 60 MeV S7+, the hydrogen content in hydrogenated amorphous silicon films has been measured during annealing in vacuum. Decrease in the hydrogen content, resulting from hydrogen evolution, was observed when the samples were heated above 300°C. The results demonstrate the usefulness of this technique for measuring average hydrogen content within the films.
Quantized Electrical Field Effect in Granular Superconductor Thin Films
Authors: Yoshikawa Nobuyuki , Murakami Tadashi , Sugahara Masanori
Published: February 2005

In this report, we describe an experimental study of the quantized electrical field effect in granular superconductor thin films which are regarded as two-dimensional arrays of small superconductor junctions. The periodic variation of the film conductance appears with the induction of a pair electron charge on each grain. The maximum variation ratio of the experimentally observed film resistance is about 40%. Besides the periodic field effect, the reproducible aperiodic conductance variation is also observed. These periodic and aperiodic field effects are explainable supposing the presence of intergrain junctions with phase quantum tunneling (PQT) behavior which is dual to the Josephson effect.
Grain-Reorientations in Y–Ba–Cu–O Ceramic Superconductors
Authors: Ashok Challa , Venkataramani N. , Shetty M. N.
Published: February 2005

Highly grain-reoriented YBa2Cu3O
x
(YBCO) bulk samples have been produced by cold pressing and annealing treatments. Grain-reorientation was improved by repeated annealing around the tetragonal-to-orthorhombic phase transition temperature in flowing oxygen. The grain-reorientation was found to be sensitive to the superconducting phase purity.
Double-Pulse Operation in XeCl Excimer Laser for Simulation of High-Repetition-Rate Performance
Authors: Takagi Shigeyuki , Okamoto Noboru , Sato Saburo , Goto Tatsumi
Published: February 2005

In order to simulate laser performance at high-repetition rates, sequential discharge pulses (double pulse) were generated in a XeCl laser gas mixture. Various aspects of the discharges and the laser power of the second pulse were observed, while varying the pulse interval from 1 s to 1 ms. With shortening of the interval, some white streamers first appeared in the glow discharge which finally changed into a high-intensity red arc. In the discharge transition from glow to arc, the laser pulse width was reduced first, followed by peak intensity decrease. The arc-onset pulse interval, T
th, was investigated at gas flow rates from 0 m/s to 6.2 m/s. The values of 1/T
th almost coincide with the laser repetition rate at which the average power begins to diminish under continuous operation. Double-pulse operation is an effective means to estimate the upper limits of the laser repetition rate.
Synthesis and Crystal Structure of a Novel Organic Ion-Complex Crystal for Second-Order Nonlinear Optics
Authors: Okada Shuji , Masaki Atsushi , Matsuda Hiro , Nakanishi Hachiro , Kato Masao , Muramatsu Ryoji , Otsuka Masaaki
Published: February 2005

The novel organic ion-complex crystal composed of protonated merocyanine and p-toluenesulfonate anion, i.e., 1-methyl-4-(2-(4-hydroxyphenyl)vinyl)pyridinium 4-toluenesulfonate (MC-PTS), was synthesized for second-order nonlinear optics. Crystal structure analysis revealed that MC-PTS crystallized in the space group of P1, i.e., the most desired space group for waveguide applications where molecular dipoles are perfectly aligned in one direction. It was also pointed out that the tetrahedral sulfonate anion plays the role of a chiral handle to give noncentrosymmetric space groups.
Kβ X-Ray Emission and K X-Ray Absorption of Chlorine in K2ReCl6, K2OsCl6, K2IrCl6 and K2PtCl6
Authors: Sugiura Chikara
Published: February 2005

The chlorine Kβ emission spectra of a series of compounds K2MCl6 (M=Re, Os, Ir and Pt) and the chlorine K absorption-edge spectrum of K2ReCl6 are measured and presented along with the chlorine K absorption-edge spectra of K2OsCl6, K2IrCl6 and K2PtCl6, reported previously. The emission spectra consist of a prominent peak with a low-energy shoulder. The absorption-edge spectrum of K2ReCl6 is composed of a sharp double peak and an intense broad structure.
The Composition Dependence of Some Electrical Properties of FeSix Thin Films
Authors: Komabayashi Masashi , Hijikata Ken-ichi , Ido Shunji
Published: February 2005

The composition dependence of the Seebeck coefficients and the microstructures of FeSi
x
thin films were studied. In the region of x<2.06, the Seebeck coefficients and amounts of the FeSi2 phase increase with increasing x. The results of electrical resistivity measurements and the analysis of the constituent phases indicate that there are two forms of the FeSi phase. In one form, the FeSi phase exists continuously along the grain boundary of the FeSi2 phase and in the other, it is surrounded by FeSi2. In the region of x>2.08, the Seebeck coefficient is negative. From the results of the d-spacing measurements, it is inferred that the excess Si in the sample with x>2.08 induces structural defects in the FeSi2, which provides the donor.
A Modulated Structure in a Fluorite-Type Fast-Ion-Conductor δ-(Bi2O3)1-x(Nb2O5)x
Authors: Miida Rokuro , Tanaka Michiyoshi
Published: February 2005

The modulated structure of the fluorite-related δ-(Bi2O3)1-x
(Nb2O5)
x
compounds was investigated by electron diffraction, high-resolution electron microscopy and X-ray powder diffraction. It was described by the substitutional and displacing waves with a common wave number vector q

k

111. The value of q increased from 0.360 to 0.383 with increasing x from 0.13 to 0.24. The substitutional waves were expressed by 0.2–0.042·cos 2πq
x/d
111 for cations and 0.15+0.039·cos 2πq
x/d
111 for anions. The displacing waves were expressed by 0.0029d
111·sin 2πq
x/d
111 and 0.171d
111·sin 2πq
x/d
111 for cations and anions, respectively. The Debye-Waller factor for O2- ions was determined as about 10 Å and 4.2 Å2 with O2- ions to occupy the 8(c) and 32(f) sites, respectively.
A Complementary Method of Determining the Temperature of a Pulsed Plasma
Authors: González Manuel I. , Pérez María C. , Rosa María I. de la , Mar Santiago
Published: February 2005

This work provides a method of determining the time evolution of the electron temperature of a pulsed plasma, in the case in which the standard techniques fail during some of the time intervals of the plasma life. The concept of the method consists of using data corresponding to the intervals at which the temperature is known to determine the parameters that relate it to the intensity of a given line. In the remaining time intervals the temperature can be computed with the help of these parameters. As an example, we will present the case of a pulsed helium plasma.
Theory of Measurement of Collision Kerma in Photon Beams with an Ionization Chamber
Authors: Shiragai Akihiro
Published: February 2005

Despite the accepted limitation to the determination of exposure for photons of energies higher than a few MeV, it is shown that the collision kerma for a suitable material or the exposure is a measurable quantity which is useful to describe the high-energy photon field. These quantities are measured at a point in free space or inside a material different from air by using ionization chambers, which have small gas cavities, calibrated in terms of exposure, air kerma or absorbed dose in the cavity gas for photons of a specified quality. As for measurements of collision kerma in soft tissue, the correction factor for attenuation and scatter in the wall and buildup cap of the chamber when exposed in air to the calibration photons or user's beams may be experimentally determined if the chamber wall and buildup cap are of tissue-equivalent materials.
Focused High-Energy Heavy Ion Beams
Authors: Horino Yuji , Chayahara Akiyoshi , Kiuchi Masato , Fujii Kanenaga , Satou Mamoru , Fujimoto Fuminori
Published: February 2005

A focused ion beam line of MeV heavy ions has been developed by combining a focusing system consisting of objective slits and a magnetic quadrupole doublet to the beam line of a tandem-type accelerator. The demagnification factors of this system were determined to be 1/3.4 for the horizontal direction and 1/14 for the vertical direction, and a minimum beam spot size of 5.6 µm×8.0 µm was achieved. This system allows us ion beam processes such as maskless MeV ion implantation and ion beam microanalysis using heavy ions.
Optical Beam Scanner with Phase-Variable Semiconductor Waveguides
Authors: Moriki Kazunori , Ohnishi Yoshihumi , Uchida Hiroshi , Hattori Takeo , Iga Kenichi
Published: February 2005

An optical beam scanner which has the possibility of high-speed steering has been fabricated and its steering operation was confirmed. The obtained deflection angle was 0.67 degrees under 9.5 V reverse bias.
Effect of Angular Distribution of Ejected Atoms from a Target on the Uniformity of Thickness and Composition of MoSix Sputtering Films
Authors: Yamazaki Toshinari , Matsuda Kenji , Nakatani Hideo
Published: February 2005

The distribution of the thickness and the composition of MoSi
x
films formed by the DC magnetron sputtering method was measured by varying the distance between the target and the substrate and the distribution of the erosion depth of the target. The angular distribution of the ejected atoms from the target is expected to affect the uniformity of the thickness and the composition. A model involving the effect of the angular distribution was considered to calculate the thickness and the composition, and the data were analyzed using the model. The model accounted for the data fairly well, and it was concluded that the angular distribution of the ejected atoms was very important in the determination of the distribution of the thickness and especially of the composition.
Rapid Cleaning of Boronized Walls with a Chlorine/Hydrogen Glow Discharge
Authors: Toyoda Hirotaka , Hanami Atsuo , Sugai Hideo
Published: February 2005

Chlorine/hydrogen discharge cleaning was developed to remove boron films coated on walls of nuclear fusion devices. The removal rate of boron films (∼0.1 Å/s) was an order of magnitude faster than that obtained by conventional hydrogen discharges. Mass spectroscopic measurement revealed that BCl3 is a main volatile product in the removal process. Chlorine contaminants after film removal were cleaned up by additional hydrogen discharges.
Automized Recognition of Partial Discharges in Cavities
Authors: Gulski Edward , Morshuis Peter H. F. , Kreuger Frederik H.
Published: February 2005

A simultaneous analysis of several parameters was used to study the possibilities of recognizing specific patterns of partial discharges in a dielectric. A computer aided discharge analyzer was used to test two types of cavities: dielectric bounded and electrode bounded. The following discharge parameters were registered: ignition voltage, discharge magnitude and phase position. The discharge data were processed using statistical tools like cross-correlation and skewness. A combination of statistical and discharge parameters offers a strong discriminator between the two types of cavities studied and can be a usefull step into developing an expert system for the recognition of different kinds of defects in insulation.
Angular Dependence of Transmissivity in a High-Pass Optical Filter for Thomson Scattering Measurement
Authors: Yamauchi Toshihiko , Dimock Dirck
Published: February 2005

The angular dependence of a high-pass optical filter for Thomson scattering is measured. Increasing the angle of incidence decreases the transmittance on the long-wavelength side in the experimental curve (the wavelength of 80% transmissivity shifts from 690 nm to 620 nm, as the angle of incidence goes from normal incidence to 45 degrees).
ESR Study of Latent Image Specks in Silver Halide Crystals
Authors: Sonoike Sanemi , Yoda Ryuuichi
Published: February 2005

So-called conduction electron spin resonance (CESR) signals of silver specks in silver halide crystals quenched from melt with excess silver are studied in relation to the quantum size effect. The proportionality relationship betweeng-shift and half-width is verified in the gradual growth of silver specks. The early stage of silver growth is attributed to the accumulation of silver atoms onto the antisite silver atoms. The gradual growth rate is explained by taking account of the electric field effects of a trapped electron. Theg-shift and half-width are indifferent of temperature, and the Kawabata theory is partly revived phenomenologically instead of the Myles theory to explain the number of silver atoms in a particle of latent images.
A Projective Analysis for the Arbitrarily-Located Wire Antenna above a Circular Finite Disk
Authors: Hassan Mohamed A.
Published: February 2005

A numerical investigation is presented here to analyse an arbitrarily-oriented thin conducting wire antenna located anywhere near a circular metallic finite thin disk. An entire domain solution of Galerkin projective method is used. The approach deals also with a monopole attached to the disk and suggests a treatment specially devoted to the singularity arising in such a case. Numerical results are presented for the current distribution and radiation pattern. The input impedance is also considered, in the investigation, at different frequencies so that the effect of change of the electrical size of the disk-monopole structure is illustrated. The study is performed for different positions of the monopole with different orientations, and shows good agreement with previous published experimental and numerical techniques.
Direct Observations of Melting and Solidification of Bi–Pb–Sr–Ca–Cu–O Compound
Authors: Hoshizaki Hiroki , Kawabata Sanemasa , Kawahara Nobuaki , Enami Hiroyoshi , Shinohara Toshiyuki , Imura Toru
Published: February 2005

Melting and solidification of Bi–Pb–Sr–Ca–Cu–O compound were directly observed by means of high-temperature optical microscopy. Crystals which appeared in heating and cooling processes were analyzed by means of micro-X-ray diffraction analysis and electron probe microanalysis. In heating, a pressed powder of the high-T
c phase, (Bi, Pb)2 Sr2Ca2Cu3O
y
, started melting at about 910°C and the melt was separated into two different liquid phases on a sapphire plate at about 1000°C. In cooling, crystals of the Ca2CuO3 phase and the low-T
c phase, (Bi, Pb)2Sr2CaCu2O
y
, were obtained from these two liquid phases and no single crystals of the high-T
c phase appeared.
Parallel Computing of Modified Signed-Digit Addition and Subtraction Using a Hybrid Optical Computing System Constructed of PROM Devices
Authors: Ueyama Kenji , Chen Jing , Minemoto Takumi
Published: February 2005

An encoding method for optical implementation of addition and subtraction in the modified signed-digit number system is proposed. Parallel computing of the addition is demonstrated by the use of a hybrid optical computing system constructed of PROM devices and electronic circuits.
Effects of Oxygen in CaS:Eu Active Layers on Emission Properties of Thin Film Electroluminescent Cells
Authors: Abe Yoshio , Onisawa Ken-ichi , Ono Yoshimasa A. , Hanazono Masanobu
Published: February 2005

CaS:Eu active layers for thin film electroluminescent (TFEL) cells were deposited by the electron beam evaporation method under several partial pressures of oxygen, and the effects of oxygen in CaS:Eu active layers on EL characteristics were studied. With increased deposition pressure, the amount of oxygen in the CaS:Eu thin films increased. The EL efficiency and PL intensity due to Eu2+ ions decreased, and absorption intensity due to Eu2+ ions decreased. In addition, Eu3+ emission peaks were observed in the EL spectrum of the cell prepared at a higher deposition pressure (3×10-2 Pa). From these results, it was concluded that oxidation of Eu ions (Eu2+→Eu3+) occurred and the concentration of Eu2+ ions decreased by adding oxygen during active layer deposition.
All Screen-Printed CdS/CuInSe2 Solar Cells
Authors: Kuhaimi S. A. AL , Bahammam S.
Published: February 2005

Thick film technology offers advantages of low cost, product amenability and automation. This technology has been successful in the manufacture of solar cells using CdS/CdTe heterojunctions. It enables the use of the same equipment in various processes involved in manufacturing solar cells. In the present work, n-CdS/p-CuInSe2 solar cells are prepared by screen printing and sintering pastes which contain the semiconductors. An efficiency of 8.75% is achieved. Electron affinity difference, saturation current and diode quality factor are measured. They are 0.49 eV, (0.9–1.8)×10-7 A, 1.5 respectively. Microstructure and electrical properties of sintered CdS films containing 10, 20, 30 and 40 wt% CdCl2 are investigated. Optimum results are obtained for the CdS films containing 10 wt% CdCl2.
Deposition of Diamond onto an Aluminum Substrate by DC Plasma CVD
Authors: Nakao Setsuo , Noda Mikio , Kusakabe Hiroshi , Shimizu Hideki , Maruno Shigeo
Published: February 2005

Diamond films are deposited on an aluminum substrate under a constant high discharge current (I
d=700 mA) and a methane concentration of about 2% by DC plasma CVD, and their structural characteristics resulting from the difference in substrate temperature (T
s: 140–480°C) are investigated. Many diamond particles with an average size of 0.3 µm and having a clear crystal habit are formed at T
s about 480°C. When T
s is decreased, the deposited films tend to contain hydrogenated amorphous components as well as amorphous carbon phases. The films deposited at extremely low T
s, such as 140°C, are composed of submicron grains like pebbles, in which nanocrystalline diamond crystals and amorphous phases having C–C and C–H bonds aggregate to form these submicron grains. It has been found that diamond films with different grain morphology are deposited on the Al substrate.
Monodomain of the Focal Conic Texture in Cholesteric Liquid Crystals
Authors: Nawa Nobuhiko
Published: February 2005

The growth process of isolated focal conics is investigated under orthogonal electric and magnetic fields. It is found that isolated focal conics elongate parallel to the magnetic field. This results in the monodomain of densely packed focal conics having the helical axis perpendicular to the orthogonal fields.
Simultaneous Imaging of a Graphite Surface with Atomic Force/Scanning Tunneling Microscope (AFM/STM)
Authors: Sugawara Yasuhiro , Ishizaka Tatsuya , Morita Seizo
Published: February 2005

We observed the graphite surface in air with an atomic force/scanning tunneling microscope (AFM/STM) system. We obtained atomically resolved AFM and STM images simultaneously under two types of operating modes. In the case of a constant height mode, the AFM (variable force) image showed the hexagonal pattern, while the STM (variable current) image showed the trigonal pattern. On the other hand, in the case of a constant current mode, the AFM (variable force) and STM (constant current) images showed the same trigonal pattern, but those patterns were out of phase with each other. We further investigated the effect of an oxide layer of a lever surface on simultaneous observation of AFM and STM images under the constant height mode.
Statistical Behavior of Secondary Electron Emission from Copper by Obliquely Incident Electrons at keV Energies
Authors: Ohya Kaoru , Mori Ichiro
Published: February 2005

Secondary electron emission of copper bombarded by a keV electron is investigated by using a statistical distribution of the secondary electron yield with a Monte Carlo calculation. The results show that the dependence of the secondary electron yield on the angle of incidence is suppressed from an inverse cosine because of the increase of backscattered electrons emitted from the surface just after the incidence.
Laser-Enhanced Ionization Signals Obtained with Microwave Resonant Cavities
Authors: Fukasawa Teruichiro , Suzuki Takanori , Misu Akira , Kasuya Takahiro
Published: February 2005

A systematic study, both experimental and theoretical, is described for an analysis of the laser-enhanced ionization (LEI) detection scheme with a microwave resonant cavity. Signal intensity for various resonant modes is consistent with the result of a numerical calculation based on a plasma-microwave interaction. The LEI signals of sodium atoms aspirated into a C3H8/O2 flame have been observed down to the concentration of 0.1 ng/mL. Broad band LEI signals have also been observed in a fuel-rich flame and are considered to be due to laser-induced heating and subsequent thermal ionization of large molecules.
TSEE Response of Sputtered MgO Films to Low-Energy X-Ray Doses
Authors: Huzimura Ryoitiro , Ogita Katsunori
Published: February 2005

MgO films doped with various elements have been prepared by means of Ar rf-sputtering and the response of thermally stimulated exoelectron emission (TSEE) to a soft X-ray dose has been measured using a GM counter of the gas flow type. The films doped with 0.1% of KCl or Al2O3 seem to be promising for dosimetry use, showing a sensitivity to X-rays below 2 keV at an exposure level of 0.3 R. To estimate the level, the X-ray energy dependence of the TSEE response is studied and compared with that of typical TL dosimeters.
Correction of the Transmittance Scale of a Double-Beam Spectrophotometer Using the Double-Aperture Method
Authors: Mito Akihiro , Takahashi Chiharu
Published: February 2005

The double-aperture method has been used to correct the nonlinearity of the transmittance scale of an accurate double-beam spectrophotometer. The nonlinearity was found to be mainly due to the detector (photomultiplier) and slightly due to electronics (a bit error of the A/D converter). Transmittance correction quantities have been determined to permit measurements to an accuracy of better than 10-4 transmittance units.
Breathing Monitor Using Dye-Doped Optical Fiber
Authors: Muto Shinzo , Fukasawa Akihiko , Ogawa Takayuki , Morisawa Masayuki , Ito Hiroshi
Published: February 2005

A new monitoring system of human breathing using umbelliferon dye-doped plastic fiber has been studied. Under UV light pumping, the fiber which was used as a sensor head generates blue fluorescence depending on human expiration. By converting the light signal to electronic pulses, the counting of breathing and real-time monitoring of abnormal breathing such as a heavy cough or a cloggy sputum have easily been obtained.
XPS Study on the Electronic Structure of Bi2Sr2Ca1-xNdxCu2Oy
Authors: Tanaka Kazuhide , Takaki Hiromu , Koyama Kuniyuki , Noguchi Seiichiro
Published: February 2005

XPS core level and valence band spectra of sintered Bi2Sr2Ca1-x
Nd
x
Cu2O
y
which manifests a superconducting to semiconducting phase change around x=0.5 have been measured. The fraction of Cu1+ to the total Cu ions evaluated from Cu2p spectra amounts to 7% in Bi2Sr2CaCu2O
y
, but decreases to 0% with increasing Nd content. From Ca2p, Sr3d, Nd3d, Bi4f and O1s spectra, it is inferred that Ca2+ and Sr2+ are mixed and distributed over both Ca and SrO layers, whereas Nd3+ and Sr2+ are rather separate. From the valence band spectra, a finite density of states at E
F is deduced for Ca-rich oxides, but it diminishes in Bi2Sr2NdCu2O
y
. The analysis of ionic configurations based on the mixed valencies of copper and oxygen ions gives a consistent account of the above spectra and the superconductor to semiconductor transition.
Selective Heteroepitaxial Growth of (100)-MgO/(001)-Y1Ba2Cu3Oy on MgO Substrate and Its Superconductivity
Authors: Sakuta Ken , Asano Katsunori , Awaji Takahiro , Hashiguchi Shoichi , Kobayashi Takeshi
Published: February 2005

The selective Y1Ba2Cu3O
y
epitaxial growth and, as its advanced technology, MgO/Y1Ba2Cu3O
y
selective heteroepitaxy are demonstrated. The film growth was done by the pressure-controlled magnetron sputtering on the MgO substrate with partial SiO coating. The epitaxial Y1Ba2Cu3O
y
films were grown in the patterned shape through a SiO window, showing the critical temperature of 77 K. In the remaining wafer region where the film contacted the underlying SiO, significant Si and Ba interdiffusion was found, resulting in the amorphous and insulating Y-Ba-Cu-Si-O. In the same way, the selective heteroepitaxy was also successfully obtained.
Molecular Field Analysis of Ce, Ga:DyIG Films
Authors: Alex Michael , Crain Jason
Published: February 2005

We report here the results of molecular field analysis of the temperature dependence of magnetization of Dy2Ce1Fe4.2Ga0.8O12 sputtered films that displayed large variations in compensation temperature due to different sputtering conditions. A three sublattice model was used to compute the molecular field coefficients and estimate the Ga and Fe2+ site distribution. The model accounted for the reduced moment of Fe2+, known to be present due to the relatively high concentrations of tetravalent Ce measured in the films. Calculations show that upon an increase in the Ga tetrahedral site and Fe2+ octahedral site occupancies, as well as upon increasing the concentration of Ce3+, large increases in the compensation temperature can be expected.
Structures and Magnetic Properties of Fe/Co Multilayer Films Prepared by DC Sputtering
Authors: Haga Yumiko , Nakamura Yoshio , Nittono Osamu
Published: February 2005

We have synthesized Fe/Co multilayer films with various layer thickness ratios by a two-facing-target-type dc sputtering method. The film texture and microstructure of as-deposited films were characterized by X-ray diffraction and by cross-sectional transmission electron microscopy. The films are constructed with alternately stacking Fe(110) and Co(0001) planes. A good orientation relationship between constituent Fe and Co layers is realized over several layers. When the thickness of each layer is equal, the saturation magnetization (4πM
s) is a constant of about 2 T (20 kGauss) regardless of layer period. No remarkable layer period dependence of the coercivity is seen.
Fabrication of Cu-Doped CdS Cell by an All-Evaporation Process and Its Photovoltaic Properties
Authors: Kashiwaba Yasube , Kirita Hitoshi , Abe Hideshi , Ikeda Toshio
Published: February 2005

Thin-film photovoltaic cells using a Cu-doped CdS layer have been fabricated by an all-evaporation process. The cells were fabricated by successive deposition of Cu(≃ 10 nm), thin CdS(≃ 0.5 µm), thick CdS(≃ 4 µm) and Al(≃ 0.1 µm) layers on the transparent SnO2:F film of the glass substrate. Deposition conditions such as substrate temperature during each deposition process and the thickness of each layer determine the distribution of Cu in the CdS layer and strongly affect the spectral response and the total efficiency. The conversion efficiency of the best cell was 6.3% for the illumination from the W-lamp. The i-n homojunction model was proposed for the formation of a potential barrier of 0.60∼0.65 eV.
Ge:Ga Far-Infrared Photoconductor with Low Compensation
Authors: Hiromoto Norihisa , Saito Minoru , Okuda Haruyuki
Published: February 2005

A sensitive Ge:Ga photoconductor was developed, and the performance of the far-infrared detector was studied for application to astronomical and atmospheric observations using stratospheric balloons. The Ge:Ga photoconductor had a response up to 110-µm wavelength and a high responsivity of R = 8.0 A/W at 4.2 K. The product of quantum efficiency and photoconductive gain ηG was 0.11, and the photoconductive gain G was estimated to be 0.36 at a half bias field of breakdown. The N
E
P was 8.5 × 10-16 W/√Hz operated at 4.2 K. Both the resistivity and the breakdown field of the Ge:Ga detectors showed that the compensation of this crystal K=N
d/N
a (donor concentration/acceptor concentration) was rather low, that is, less than 10-2. The Photoconductor's high responsivity could be attributed to the high photoconductive gain produced by the low compensation.
Morphology of Zn3P2 Needle Crystals
Authors: Kuroyanagi Akio
Published: February 2005

Needle-shaped single crystals of zinc phosphide were grown from the vapor phase by sublimation of as-synthesized Zn3P2. The size of Zn3P2 needle crystals is 0.1-0.5 mm in diameter and 10-15 mm long. The growth direction of needle crystals is found to lie along the [201] axis by the X-ray Laue measurement.
Conductivity Mechanism of Cs-Sb-Type Photoemissive Cathode Film
Authors: Hirohata Toru , Mizushima Yoshihiko
Published: February 2005

For analyzing the long tail of a spectral response curve of a Cs-Sb-type photocathode, we propose that the Cs-Sb-type photocathode is conveniently interpreted on the basis of an amorphous semiconductor like concept. 1) In a spectral response of photoemission, a gentle exponential tail exists in the long-wavelength region. It is possible to explain this phenomenon by the existence of interband states. 2) At low temperatures, the electrical resistivity has a temperature dependence of T
-1/4. This behavior implies that the cathode film has an amorphous-type conductivity: i.e., variable-range hopping conduction. This is futher evidence of the amorphous like interband states which limit the photoemission.
DC Bias Method for a-Si:H Deposition on a Dielectric Substrate Using Electron Cyclotron Resonance Plasma
Authors: Nakayama Yoshikazu , Kondoh Mitsuru , Hitsuishi Kohji , Kawamura Takao
Published: February 2005

A new DC bias method applicable to a-Si:H deposition on the dielectric substrate using an electron cyclotron resonance (ECR) plasma is investigated. A reactor consists of an ECR chamber and a deposition chamber, where a DC bias voltage is applied to a substrate holder against a grounded mesh set between two chambers. The optimum bias voltage exists in the positive region, and the highly photosensitive a-Si:H is deposited on the glass substrate.