TANSO
Online ISSN : 1884-5495
Print ISSN : 0371-5345
ISSN-L : 0371-5345
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Volume 1972, Issue 71
Displaying 1-8 of 8 articles from this issue
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  • [title in Japanese]
    [in Japanese]
    1972 Volume 1972 Issue 71 Pages 108-114
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.108
    JOURNAL FREE ACCESS
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  • Galvanomagnetic Effects in Graphite-Halogen Residue Compounds
    Kenji TASHIRO, Mitsuhiro SAITO, Takuro TSUZUKU
    1972 Volume 1972 Issue 71 Pages 115-119
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.115
    JOURNAL FREE ACCESS
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    By means of a precision dc-amplification technique, the halogen-dope effect on galvanomagnetic properties of a reactor-grade polycrystalline graphite has been investigated at liquid nitorogen temperature in the range of magnetic field intensity up to 10 kG. Br2 and IC1 were chosen as dopants respectively.
    When the halogen concentration was order of 10-2 at. % or less, the transport properties were little affected by the presence of such impurities. This may imply that most parts of impurities precipitate probably to inter-crystallite boundaries in the form of clusters. As the concentration increases beyond 10-1 at. %, the Hall coefficient changes its sign and the resistivity as well as the magnetoresistance tends to decrease by a factor of more than two; which means that halogens flood into the crystallites so as to change the electronic structure. In the X-ray diffraction study examined at the same time, it has been observed that the d (004)- spacing is subjected to little change but the crystallite size La to considerable decrease. Qualitative discussions are given of the data in terms the simple two-band scheme, which has led to a conclusion that the ionization efficiency of these halogen impurities is pretty low.
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  • Thermolectricity and Magnetoresistance of Carbon Fibers
    Shiro ARAI, Takuro TSUZUKU
    1972 Volume 1972 Issue 71 Pages 120-123
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.120
    JOURNAL FREE ACCESS
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    Electronic processes in carbon fiber have been studied. Experimentation was madeon the thermoelectric effect and the transverse magnetoresistance effect at temperatures between 77 K and 300 K. The absolute thermoelectric power (S) is positive and exhibits a monotonical increase with temperature, while the magnetoresistance (Δρ/ρ) is negative in the magnetic field (H) range examined (≤15 kG). There is found, however, an indication that Δρ/ρ reaches a minimum at H not much exceeding 15 KG. In terms of the conventional two-band scheme, these observations imply that the Fermi level is pretty much depressed into the lower π-band, and hence positive holes are of absolute majority. Some analytical discussions are given on this basis.
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  • Relations among X-ray Parameters and Graphitization Process III
    Relations between Strain and co-spacing for Various Carbons
    Michio INAGAKI
    1972 Volume 1972 Issue 71 Pages 124-127
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.124
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    For polyvinylchloride coke, three kinds of petroleum cokes having different needle-like nature, thermal black having the average diameter of about 3000 Å, and four kinds of chars made of polyaromatic compounds, the strain εc was measured from half widths of 002 and 004 diffraction lines and discussed in relation to co-spacing co.
    The polyvinylchloride cokes heat-treated under different conditions, that is, under reduced pressure, under a high pressure of 1 kbar and in the flow of nitrogen, and three petroleum cokes showed the same relation betweenεc and co, although the changes of co with heat treatment were very different. The thermal black and three polyaromatic compound chars had the different relation between εc and co from that for cokes. Non-graphitizing carbons were found to have larger value of εc, particularly for the co-spacing ranging from 6. 85 to 6.75 Å, than graphitizing carbons. In order to characterize the graphitization state, in other words, the structure, of the heat-treated carbons, not only co-spacing but also strain εc, for example, should be measured.
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  • Electrical Properties of Carbon Materials under Hydrostatic Pressure; Teflon Capsule Method
    Kiyoshi NOTO, Takuro TSUZUKU
    1972 Volume 1972 Issue 71 Pages 128-131
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.128
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  • Transparency Factor for X-ray Diffractometry
    Isao TOMIZUKA, Kiyoshi SHIRAI, Osamu WATANABE
    1972 Volume 1972 Issue 71 Pages 131-133
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.131
    JOURNAL FREE ACCESS
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  • Relation between Amount of Benzene Insolubles and of Quinoline Insolubles for Coal Tar Pitch
    Yuzo SANADA, Takeshi FURUTA, Junjiro KUMAI, Hideo KIMURA
    1972 Volume 1972 Issue 71 Pages 133-134
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.133
    JOURNAL FREE ACCESS
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  • [title in Japanese]
    [in Japanese], [in Japanese]
    1972 Volume 1972 Issue 71 Pages 135-148
    Published: November 05, 1972
    Released on J-STAGE: June 28, 2010
    DOIhttps://doi.org/10.7209/tanso.1972.135
    JOURNAL FREE ACCESS
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