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[Author] Nobuyuki IWATA(3hit)

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  • Crystallization and Conductivity of ReO3 Thin Films Prepared by 90Off-Axis RF Magnetron Sputtering Method

    Nobuyuki IWATA  Kumiko FUKAI  Hiroshi YAMAMOTO  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    223-226

    We investigated growth conditions of the ReO3 thin films, as a first step of establishment of artificial superconducting multi-layer with the infinite layer cuprate and ReO3. The layers of ReO3 were expected to work as a charge reservoir block. The films were deposited from a Re metal target by off-axis reactive sputtering. Conductive and preferentially (100) oriented ReO3 thin films were obtained by in-situ post-annealing. The lowest resistivity was 4.4 10-5 ohmcm at room temperature.

  • Free Electron Laser-Polymerization of C60 Grown by Liquid-Liquid-Interfacial Precipitation Method

    Daiki KOIDE  Shouta KATO  Eri IKEDA  Nobuyuki IWATA  Hiroshi YAMAMOTO  

     
    PAPER

      Vol:
    E94-C No:2
      Page(s):
    151-156

    The purpose of this work is to synthesize a three-dimension C60 polymer using photo-polymerization method. The used pristine materials were C60 precipitates prepared by a liquid-liquid interfacial precipitation (LLIP) method. The prepared LLIP material was set in the vacuum and was compressed in the anvil with the pressure of 600 MPa or 7 GPa. The 4th harmonics FEL with the wavelength of 500 nm was irradiated with macro-pulses (the pulse width of 20 µs) containing very short micro-pulses (the pulse width of 200 fs). The Raman Ag(2) peak of C60 molecules in the vicinity of 1469 cm-1 becomes broad and shifts to the lower energy region as proceeding of polymerization. Under high pressure and/or FEL irradiation the LLIP crystal revealed the large red-shift and the increment of the half width of the Raman Ag(2) peak. Furthermore the LLIP crystal mixture with iodine revealed the more distinctive red-shift, ca.13cm-1 because of highly packing of C60 molecules. The C60 molecular accession by LLIP process and/or the photo-assisted hole-doping from iodine were promising conditions to promote the photo-polymerization effectively.

  • Growth Position and Chirality Control of Single-Walled Carbon Nanotubes

    Keijiro SAKAI  Satoshi DOI  Nobuyuki IWATA  Hirofumi YAJIMA  Hiroshi YAMAMOTO  

     
    PAPER

      Vol:
    E94-C No:12
      Page(s):
    1861-1866

    We propose a novel technique to grow the single-walled carbon nanotubes (SWNTs) with specific chirality at the desired position using free electron laser (FEL) irradiation during growth and surface treatment. As a result, only the semiconducting SWNTs grew at the area between triangle electrodes, where the ozone treatment was done to be hydrophilic when an alcohol chemical vapor deposition (ACCVD) process was carried out with the 800 nm FEL irradiation. Although the number of possible chiral index is 22 in the SWNTs grown without the FEL irradiation, the number is much reduced to be 8 by the FEL.