第276回物性セミナー
題目:Vibrational Properties and Superconductivity
in Metal-doped Si Clathrates
講師:Prof. John Sak Tse 氏
(Department of Physics and Engineering Physics, University of Saskatcehwan, Canada)
日時:2006年5月29日(月)14:30〜
場所:広島大学先端物質科学研究科 304S
講演要旨
The electronic and vibrational structures of Ba8Si46, Ba24Si100 and Ba8MnSi46-n, where some of the framework Si were replaced by metal (M=Ag, Au) have been studied. Theoretical calculations show that the nature of chemical bonding of the substituted clathrates and their vibrational properties are fundamentally different from Ba8Si46.
Low-frequency vibrations associated the motions of Ba in the small cages and the framework metals have been identified from their Raman spectra. A surprising finding is that not all the
low frequency Ba <rattlingc modes contribute to the electron-phonon coupling process. It was found that only the vibrational modes from Ba in the large cage help to mediate the electron-phonon coupling in Ba8Si46 and Ba24Si100.
−4研究科共同セミナーの認定科目です−
−後援 先進物質機能研究センター−
本セミナーの担当: 山中昭司(工学研究科)内線7740
物性セミナー世話人:高根 美武(内7653) 浴野 稔一(内6552)
中村 文彦(内7042) 木村 昭夫(内7471)
犬丸 啓(内7741)
広報担当:伊賀文俊(内7026)