論文

査読有り
2019年11月

Pressure-Induced Collapse of the Guest Eu Off-Centering in Type-I Clathrate Eu8Ga16Ge30

Journal of the Physical Society of Japan
  • Ishimatsu,Naoki
  • Yokoyama,Kei
  • Onimaru,Takahiro
  • Takabatake,Toshiro
  • Suekuni,Koichiro
  • Kawamura,Naomi
  • Tsutsui,Satoshi
  • Mizumaki,Masaichiro
  • Ina,Toshiaki
  • Watanuki,Tetsu
  • Cuartero,Vera
  • Mathon,Olivier
  • Pascarelli,Sakura
  • Nishibori,Eiji
  • Irifune,Tetsuo
  • 全て表示

88
11
開始ページ
114601
終了ページ
114601
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.7566/JPSJ.88.114601
出版者・発行元
Physical Society of Japan

We have revealed the pressure-induced collapse of the guest Eu off-centering in type-I clathrate Eu8Ga16Ge30 by the measurements of extended X-ray absorption fine structure (EXAFS) at the Ge K-edge in a temperature range of 10-300 K. Our analysis of the EXAFS spectra at ambient pressure confirmed that the guest Eu is located in the off-centered positions Delta(offset) = 0.39(1) angstrom away from the center of the Ga/Ge tetradodecahedron cage (14-cage). However, with applying pressure to 13.1 GPa, Delta(offset) decreases to zero, and the atomic density of Eu is concentrated near the center of the 14-cage with a broad distribution. The present result demonstrates a close relationship between Delta(offset) and the size of the cage Delta(offset) decreases when the 14-cage shrinks by applying pressure. With further compression, we have observed a drastic change in the EXAFS spectra due to amorphization. In the amorphous phase, the first nearest neighbor Ge-Ga/Ge bond is longer than in the crystal phase, whereas the guest Eu atom is located randomly with respect to the Ge atoms.

リンク情報
DOI
https://doi.org/10.7566/JPSJ.88.114601
URL
https://journals.jps.jp/doi/pdf/10.7566/JPSJ.88.114601
ID情報
  • DOI : 10.7566/JPSJ.88.114601
  • ISSN : 0031-9015
  • eISSN : 1347-4073

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