IEEJ Transactions on Fundamentals and Materials
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
Volume 123, Issue 2
Displaying 1-20 of 20 articles from this issue
Special Issue Review
Review
  • Toshiyuki Yokosuka, Katsumi Sasata, Akira Endou, Momoji Kubo, Akira Mi ...
    Article type: Review
    2003 Volume 123 Issue 2 Pages 114-117
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    In addition to the theoretical prediction on the properties and functions of the electric and electronics materials, the simulation on the dynamic processes, such as etching process and chemical mechanical polishing process, are strongly demanded. Recently, we have succeeded in the development of a new accelerated quantum chemical molecular dynamics program, which is more than 5, 000 times faster than the regular first-principles molecular dynamics approach. This program enables us to calculate a realistic etching process, chemical mechanical polishing process, etc., employing large simulation model. In this review, we summarize the theory of our accelerated quantum chemical molecular dynamics and its application to various dynamic processes related to the electric and electronics engineering.
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Special Issue Paper
  • Susumu Suzuki, Haruo Itoh
    Article type: Special Issue Paper
    2003 Volume 123 Issue 2 Pages 118-124
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    This paper deals with the experimental and simulation results for the electron transmission coefficient in He/Xe (10%) and Ne/Xe (10%) mixtures. From the experimental results, the diffusion region, the E/p0 dependence region and the saturation region for the electron transmission characteristic are observed in both gases. Moreover, it confirms that the electron transmission coefficient in Ne/Xe(10%) mixture becomes a higher value than that in He/Xe(10%) mixture. From the results of MCS, if the gas pressure p0 × gap length d is the constant, even though it changes the combination of p0 and d, it confirms that the experimental and simulation values for the electron transmission coefficient becomes equal. This means that we can compare the experimental results of the electron transmission coefficient with that of MCS. As the initial energy of the electron is large, the emitted electron is influenced by back scattering until the high reduced electric field E/p0. Moreover, we estimates that the experimental values agree with the case that gives the initial energy distribution with the uniformity of 0 - 1.0 eV and the electron reflection coefficient of the cathode of 0.6.
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  • Hiroki Kusunoki, Takatoshi Kondo, Kiyohiro Hiraki, Kazushi Takada, Shi ...
    Article type: Special Issue Paper
    2003 Volume 123 Issue 2 Pages 125-131
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    Grain-size dependence of electromagnetic absorbing characteristics for composite materials made of Ni-Zn ferrite and SiO2 was investigated by using SiO2 with various grain sizes (29µm, 30nm, 12nm, 7nm). The absorption characteristics of ferrite composites using SiO2 of the average grain size 30nm, 12nm or 7nm were improved compared with those of ferrite composites using SiO2 of the average grain size 29µm in the low frequency region. Furthermore, grain size dependence for composite materials of Mn-Zn ferrite with the average grain size of 130nm and SiO2 with the average grain size of 29µm was investigated. The absorbing center frequency was shifted to the higher frequency region compared with that of Mn-Zn ferrite.
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  • Akihiro Yamada, Shinzo Yoshikado
    Article type: Special Issue Paper
    2003 Volume 123 Issue 2 Pages 132-138
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    Thin film of YBa2Cu3O7-δ (YBCO) was deposited on a MgO substrate by the visible light (532nm) pulsed laser ablation method using a Nd:YAG laser. The purpose of this study is to find out the optimum composition of target and to improve the quality of thin films by introducing oxygen radicals. Thin film deposited in O2 gas at substrate temperature of 600°C and thermally annealed at 925°C in the air using a target with mol ratio of 1:2:4 of Y, Ba, and Cu (1:2:4 target) changed to the super conducting state at 69K, which was the highest among those of thin films deposited using targets with different compositions. Thin film deposited in O2 gas including oxygen radicals produced by the oxygen plasma using a 1:2:4 target changed to the superconducting state at 75K. Resistance decreased rapidly with decreasing temperature near superconducting transition temperature. Thin film deposited in O2 gas including oxygen radicals at 730°C using a 1:2:4 target without thermal annealing changed to the superconducting state at 50K.
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  • Yohei Satoi, Shinzo Yoshikado
    Article type: Special Issue Paper
    2003 Volume 123 Issue 2 Pages 139-145
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    The effects of addition of Al on the electrical degradation of the Bi, Mn, and Al added ZnO varistors and the Bi, Co, and Al added ZnO varistors were investigated by V-I, C-V, ICTS, and XPS methods. The optimum quantity of Al additive to prevent the electrical degradation is approximately 5ppm in the case of Bi-Mn-Al added ZnO varistor and approximately 10ppm in the case of Bi-Co-Al added ZnO varistor. For each optimum quantity of Al content for Bi-Mn-Al or Bi-Co-Al added varistor, the distribution of values of the energies of the trap levels became narrowest. On the other hand, values of the full width at half maximum of Mn-2p and Co-2p orbits became largest.
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  • Fumitoshi Yamashita, Akihiko Watanabe, Hirotoshi Fukunaga
    Article type: Special Issue Paper
    2003 Volume 123 Issue 2 Pages 146-152
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    The usage of high-performance rare-earth magnets is one of the key technologies in the development of efficient small motors. Ring-shaped melt-spun Nd-Fe-B bonded magnets, prepared using a powder compacting press and/or injection molding, are generally used in typical applications to small efficient motors. For exploiting the maximum characteristics according to the variety of magnetic powder, however, the preparation method of the magnet, the magnet form, and the motor design needs to be changed for high-productivity as well as for improving total performance, including the magnetic properties of bonded magnets. This paper reports recent achievements in new preparation processes for rare-earth bonded magnets and small motors using new materials other than Nd-Fe-B melt-spun powder. This paper especially focuses on the method for maximally exploiting certain rare-earth magnetic powders . Furthermore, reduction in the current consumption of the small DC motor using the developed technique is reported.
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  • Shoji Hamada, Tadasu Takuma
    Article type: Special Issue Paper
    2003 Volume 123 Issue 2 Pages 153-160
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    We propose a curved triangular patch that is suitable for the field calculation by the integral equation methods. The interior control point of this patch is variably represented in the area coordinate as a weighted average of six control points.We can connect the patch to the three surrounding patches with G1 continuity on the sides. The whole surfaces to be treated can be represented as a collection of smoothly connected patches. This patch is applied to the surface charge method with the pseudo-particle fast multipole method. We demonstrate some electrostatic field calculations using several hundreds of thousands of proposed patches.
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  • Hiroyuki Motoyama, Nobumi Hagiwara
    Article type: Special Issue Paper
    2003 Volume 123 Issue 2 Pages 161-166
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    In the material testing, the displacement measurement system is indispensable. And usually such tests are done on a lot of test pieces and are continued for long time interval. Therefore, the simplified and automated displacement measurement system is required. In this paper, the authors propose a simple automatic displacement measurement system and give some experimental results. The proposed system utilizes a grating made by the photographic technology, a pair of optical pickups for CD, and the mouse interface for a personal computer. The movement of the grating that is detected by the CD optical pickups is processed by the mouse interface and is recorded as the mouse data with the personal computer. Simultaneously, the quantity of the displacement is automatically measured by the resolution of 1/4 of the grating interval by the mouse interface. Using the prototype equipment that utilizes a grating of which line interval is 100 µm, the 25 µm resolution has been obtained under the displacement speed of 0.5 mm/s. The maximum displacement speed of the system can be extended on the theory to 400 mm/s when using the grating of 100 µm line interval, but the investigation of the practical speed is left as a next problem. Because the mouse interface can detect the two-dimensional movement, the system is easily applied to measure the elongation between two points on the test piece. As the CD optical pickup and the mouse are very popular equipments, it is easy to obtain them. At the same time, as their structure and characteristics are well known, the applicability of these devices is excellent. Also, the proposed system is a very simple system. Therefore, this system will be able to be applied to various fields.
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Paper
  • Satoshi Matsuda, Hirotsugu Shimosato, Motoshige Yumoto, Takao Sakai
    Article type: Paper
    2003 Volume 123 Issue 2 Pages 167-172
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    N2(A3u+) state has a longer radiation life time and its electron energy is high. Accordingly, it is expected to accelerate chemical reactions in the space where many metastable molecules accumulate. Thus, it is important to detect metastable molecules and to evaluate its number density. The authors used the threshold ionization mass spectrometry to detect N2(A3u+) state in nitrogen plasma. A quadrupole mass spectrometer (QMS) was used and its electron energy for ionization was controlled from 8 eV to 25eV. Magnitude of the QMS signal was compared with the ionization cross section of N2(A3u+)state by electron collision and its number density was estimated. The dependence of N2(A3u+) density on discharge current and the spatial distribution of its density were measured using the method. From the results, it was confirmed that the density of N2(A3u+) increased proportionally to discharge current and its density decreased rapidly in the vicinity of glass wall faced to discharge space.
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  • Yoshiyasu Ehara, Yuko Hiromura, Toshikazu Nomura, Shunsuke Iwasaki, Ta ...
    Article type: Paper
    2003 Volume 123 Issue 2 Pages 173-178
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    The purpose of this study is to discuss the effects of sound wave on discharge and NOx removal. Against this backdrop, we removed NOx from NO/N2 mixed gas by superimposing silent discharge and sound wave in an acoustical standing wave field. As the results, NO removal rate and efficiency increase with increasing sound pressure. In particular, highest NOx removal rate is obtained when the electrode is located at the node point of sound pressure distribution, that is, at the maximum point of the particle velocity. This result shows significant improvement on NO removal by superimposing silent discharge and sound wave. Furthermore, NO removal rate decreases with increasing resonance frequency, for the reason of decreasing amplitude of particle displacement. Therefore, it is considered that NO removal rate relates to particle velocity and amplitude of particle displacement.
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  • Yasuhiro Matsumoto, Takashi Aoki, Yukihiko Tamura, Shinji Ibuka, Koich ...
    Article type: Paper
    2003 Volume 123 Issue 2 Pages 179-184
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    Turn-on characteristics of semiconductor power devices are evaluated under external magnetic field to study the effects of external magnetic field generated in a pulsed power circuit.Two pin diodes that have a basic structure of power devices are connected in parallel and driven by a pulsed voltage source.It was found the magnetic field applied to one diode in the perpendicular direction of current-flow changed the current balance between the diodes.Besides the on-resistance of a diode was increased under external magnetic field.The carrier-density distribution inside of the diodes was measured by using a free carrier absorption method.The data show that the carrier-density distribution changes from nearly the uniform one to the one-sided one.It can be concluded that the effects of magnetic-field have to be considered for the evaluation of switching characteristic in pulsed power operations.
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  • Kenji Odagawa, Noriyuki Yanagawa, Mitsuru Sadamoto
    Article type: Paper
    2003 Volume 123 Issue 2 Pages 185-191
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    The etching process of ITO (Indium Tin Oxide) is used to form pixel electrodes of the liquid crystal displays. Though the wet etching is the mainstream in ITO etching process now, the dry etching is needed as making the pixel minute. There are few reports which systematically examine the etching characteristics by using various etching gases though some methods are proposed as for the ITO dry etching. We paid attention to inductively coupled plasma (ICP) which easily obtained high-density plasma, and examined the etching characteristics of ITO films systematically used HI, HBr, HCl and Cl2. As the result, ITO was able to be etched vertically without damaging the photoresist by using ICP of HI mixed with Ar.The damage to the photoresist was larger than that of HI in other etching gases. In addition, a high etch rate was obtained in HI compared with the case to use other etching gases. ICP used HI showed excellent characteristics in the dry etching of the ITO films.
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  • Isamu Nagano, Yoshiyuki Yoshimura, Satoshi Yagitani, Hiroaki Yokomoto, ...
    Article type: Paper
    2003 Volume 123 Issue 2 Pages 192-199
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    It is important to know the electric parameters of the shielding material for numerical analysis. The purpose of this report is to estimate electric parameters of thin shielding materials. Electromagnetic field in the vicinity of a horizontal multi-layered material with a magnetic dipole source is calculated numerically by a Sommerfeld integral. On the basis of this calculation, we develop a "shielding box" for measuring the shielding effectiveness (SE) with little error. We compare the magnetic SE measured with the shielding box with that obtained by calculation to evaluate this method. Because calculation results are in good agreement with measurement results, we confirm that we can measure magnetic SE of thin shielding materials with this system. Next, we propose a method to estimate unknown electric parameters of shielding materials by using the SE measurement system and the numerical calculation. The electric parameters are derived by iterating numerical calculations to fit with experimental results within 1dB error. We estimated the electric parameters of Al (aluminum) material. Fitted results are in good agreement with the well-known values, demonstrating the validity of the developed method.
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Letter
  • Osamu Shimomura, Makihiro Kobayashi, Izumi Osada, Yuuki Muramatsu, Tak ...
    Article type: Letter
    2003 Volume 123 Issue 2 Pages 200-201
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    Algorithm for measurement of urea concentration and ratio of solvent using pH and conductivity in aqueous solution of urea with NH4Cl was proposed. Temperature characteristics of pH and conductivity in the solution of urea concentration 200, 220, 240 and 260[g urea/100gH2O] and ratio of solvent 2.0, 2.25, 2.5, 2.75 and 3.0[g H2O/g NH4Cl] were investigated. Using their data and algorithm, measurement of urea concentration and ratio of solvent were made with error less than 5%.
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  • Akira Fujita, Shohei Kato, Takao Hirai, Shigemitu Okabe
    Article type: Letter
    2003 Volume 123 Issue 2 Pages 202-203
    Published: 2003
    Released on J-STAGE: May 01, 2003
    JOURNAL FREE ACCESS
    In electric power system a threat of lighting surge is decreased by using ground wire and arrester, but the risk of failure of transformer is still high. Winding is the most familiar conductor configuration of electromagnetic field components such as transformer, resistors, reactance device etc. Therefore, it is important that we invest the lighting surge how to advance into winding, but the electromagnet coupling in a winding makes lighting surge analysis difficult. In this paper we present transient characteristics analysis of an air-core coils by moment method in frequency domain. We calculate the inductance from time response and impedance in low frequency, and compare them with the analytical equation which is based on Nagaoka factor.
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