Calorimetric and Raman Studies on Negative Thermal Expansion Materials Zr_1-<i>x</i>Hf_<i>x</i>W₂O₈ Solid Solutions

• YAMAMURA Yasuhisa

  School of Materials Science, Japan Advanced Institute of Science and Technology

• NAKAJIMA Noriyuki

  School of Materials Science, Japan Advanced Institute of Science and Technology

• TSUJI Toshihide

  School of Materials Science, Japan Advanced Institute of Science and Technology

• KOYANO Mikio

  School of Materials Science, Japan Advanced Institute of Science and Technology

• IWASA Yoshihiro

  School of Materials Science, Japan Advanced Institute of Science and Technology

• KATAYAMA Shin'ichi

  School of Materials Science, Japan Advanced Institute of Science and Technology

• SAITO Kazuya

  Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University

• SORAI Michio

  Research Center for Molecular Thermodynamics, Graduate School of Science, Osaka University

抄録

Heat capacities of Zr_1-xHf_xW₂O₈(x=0.25, 0.5 and 0.75) were measured from 1.8 to 70 K. The heat capacity of Zr_1-xHf_xW₂O₈ increased with increasing Hf content due to atomic mass effect. Frequency distributions of lattice vibrations were estimated through an analysis of the heat capacities for Zr_1-xHf_xW₂O₈ and indicated the presence of two Einstein modes in low-energy region. The two Einstein characteristic temperatures linearly depended on Hf content. Raman spectra of Zr_1-xHf_xW₂O₈(x=0.25, 0.5 and 0.75) at room temperature showed two characteristic optical phonon modes corresponding to the two Einstein modes obtained from heat capacity analyses. Mode assignment is made of these characteristic optical phonon modes involved in the negative thermal expansion.

収録刊行物

• Journal of the Ceramic Society of Japan, Supplement

  Journal of the Ceramic Society of Japan, Supplement 112 (0), S291-S293, 2004

  公益社団法人 日本セラミックス協会

キーワード

• Negative thermal expansion
• Heat capacity
• Raman spectroscopy
• Lattice vibration
• ZrW₂O₈
• HfW₂O₈

詳細情報

• CRID: 1390001205523160576
• NII論文ID: 130004610185
• DOI: 10.14852/jcersjsuppl.112.0.s291.0
• ISSN: 13492756
• 本文言語コード: en
• データソース種別:
  • JaLC
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可