The clarified origin of the excess thermodynamic functions by XAFS

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K22464
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0401:Materials engineering, chemical engineering, and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Watanabe Manabu 東京工業大学, 物質理工学院, 助教 (50880283)
• Project Period (FY): 2020-09-11 – 2023-03-31
• Keywords: XAFS / Levitation

Outline of Final Research Achievements

XAFS measurements of Fe-Pd alloys were performed at BL01BU of the Japan Synchrotron Radiation Research Center "SPring-8" in order to clarify the origin of the thermodynamic and thermophysical excesses functions of molten metals. We were able to maintain the molten state using the gas floating jet furnace owned by SPring-8. XAFS measurements of the K-edge of Pd were successful in both solid and liquid states, however, the measurement of Fe was difficult due to the absorption of Ar gas used for floating sample. Therefore, we reexamined the inert gas for XAFS measurement and measured the thermophysical properties of the order-random transformation.

Free Research Field

溶融熱物性、熱力学

Academic Significance and Societal Importance of the Research Achievements

本研究では、規則ー不規則変態を生じる合金の溶融状態の過剰体積と過剰ギブズエネルギーとの間の負の依存性について、高輝度光科学研究センターSPring-8にてXAFS測定および浮遊法により熱物性測定を行った。XAFS測定では電子状態と構造情報の取得を目的に研究を行った。浮遊法を用いた熱物性測定は順調に行うことができ、溶融Fe-Pd、Ni-Ti合金、Au系合金などの密度、放射率、熱容量、熱伝導率および粘性測定を行うことができ、これらの物性値から過剰量との相関性について議論し、新たな溶液モデルの提唱に成功した。このような溶液モデルは、従来報告がなく学術的意味がある。