Pressure induced phase transformation of Ba8Ga16Ge30 clathrate studied by x-ray diffraction and Raman spectroscopy

• Kume, Tetsuji

• Ohno, Satoshi

• Sasaki, Shigeo

• Shimizu, Hiroyasu

• Ohishi, Yasuo

• Okamoto, Norihiko L.

• Kishida, Kyosuke

• Tanaka, Katsushi

• Inui, Haruyuki

Abstract

The phase transition and the vibrational properties of Ba8Ga16Ge30 have been investigated at high pressures up to 40 GPa at room temperature. The combined study of the high-pressure Raman and synchrotron powder x-ray diffraction (XRD) experiments revealed the occurrence of a first-order phase transition at 33 GPa, on which a volume decrease of about 3% was found. Rietveld refinements of the XRD data demonstrated the atomic displacements precursory to the phase transition, allowing us to discuss the mechanism of the phase transition. In the Raman experimental data, anomalies were observed in the spectral feature and the guest vibration around 17 GPa. By combining the Raman results with the XRD ones, the vibrational frequency of the guest Ba was investigated as a function of the host cage size. As a result, a linear relation between guest vibrational frequency and the guest-host distance was identified.

Journal

• JOURNAL OF APPLIED PHYSICS

  JOURNAL OF APPLIED PHYSICS 107 (1), 013517-, 2010-01

  AMER INST PHYSICS

Keywords

• barium compounds
• organic compounds
• Raman spectroscopy
• solid-state phase transformations
• synchrotrons
• X-ray diffraction

Details

• CRID: 1050282810697655040
• NII Article ID: 120003386586
• NII Book ID: AA00693547
• ISSN: 00218979
• HANDLE: 2433/147187
• HANDLE: 20.500.12099/35510
• Web Site: https://gifu-u.repo.nii.ac.jp/records/79006
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles
  • KAKEN