Browsing by Author "Kamishima, O"

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    Estimation of force constants of Al from diffuse neutron scattering measurement
    (The Physical Society of Japan, 2014-06-19) Makhsun; Hashimoto, T; Takahashi, H; Kamishima, O; Igawa, N; Danilkin, SA; Sakuma, T
    Neutron diffraction measurement of an aluminum powder sample at 290 K was carried out at the high resolution powder diffractometer installed at JRR-3. Broad oscillations of the diffuse scattering intensity were observed and explained by the correlation effects among the thermal displacements of atoms. The interatomic force constants were determined from the correlation effects using a newly introduced equation. The derived force constants and the crystal structure of Al were used to estimate the phonon dispersion relations, phonon density of states, and specific heat by computer simulation. The calculated phonon dispersion relations and specific heat of Al are similar to those obtained from inelastic neutron scattering and specific heat measurements, respectively.© 2014, The Physical Society of Japan.
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    Inter-atomic force constants of Ag2O from diffuse neutron scattering measurement
    (Elsevier Science BV., 2012-10-04) Wada, T; Sakuma, T; Sakai, R; Uehara, H; Xianglian; Takahashi, H; Kamishima, O; Igawa, N; Danilkin, SA
    Diffuse neutron scattering measurements have been performed on powder Ag(2)O at 8 and 295 K with the use of High Resolution Powder Diffractometer installed at JRR-3 in Japan Atomic Energy Agency. Oscillatory diffuse scattering intensities are clearly observed at 8 and 295 K. The observed diffuse scattering intensities are explained by including the correlation effects among thermal displacements of atoms. The force constants among neighboring atoms in Ag(2)O are obtained from the values of correlation effects and Debye-Waller temperature parameters at 295 K. © 2012, Elsevier Ltd.