Real Space Cluster Expansion for Total Energies of Pd-Rich PdX (X = Rh, Ru) Alloys, Based on Full-Potential KKR Calculations: An Approach from a Dilute Limit

• Liu Chang

  National Institute for Materials Science

• Asato Mitsuhiro

  National Institute of Technology, Niihama College Department of Chemistry and Biochemistry, University of California

• Fujima Nobuhisa

  Graduate School of Engineering, Shizuoka University

• Hoshino Toshiharu

  Faculty of Engineering, Shizuoka University

• Chen Ying

  Graduate School of Engineering, Tohoku University

• Mohri Tetsuo

  Institute for Materials Research, Tohoku University

抄録

We study the accuracy and convergence of the real space cluster expansion (RSCE) for the internal energies in the free energies of Pd-rich PdX (X = Rh, Ru) alloys, being used to study the phase stability and phase equilibria of Pd-rich PdX alloys in fcc structure. In the present RSCE from a dilute limit, the X atoms of minor element are treated as impurities in Pd. The n-body interaction energies (IEs) among X impurities in Pd are determined uniquely and successively from the low body to high body, by the ab-initio calculations based on the full-potential Korringa-Kohn-Rostoker Green’s function method (FPKKR) for the perfect and impurity systems (Pd-host and X_n in Pd, n = 1∼4), combined with the generalized gradient approximation in the density functional theory. We show that the total energies of the ordered Pd₃X (X = Rh, Ru; X-concentration = 25%) alloys in L1₂ structure, obtained by the screened FPKKR band calculations, are reproduced very well (within the error of ∼1 mRy per atom) by the present RSCE including the 2-body IEs up to the 20th nearest neighboring pair (X₂) and the 3-body IEs up to the clusters (X₃) in the two cubic cells in fcc structure. We clarify the contribution from each term (of the 0∼4 body terms) in the RSCE to the total energies of Pd-rich PdX alloys, the distance dependence of the 2-body (X₂) IEs, and the cluster-size dependence of 3-body (X₃) and 4-body (X₄) IEs. It is also shown that the contribution from the n-body (n = 2∼4) IEs becomes smaller and smaller with the increase in n and that the contribution from the 4-body IEs is very small (less than ∼0.2 mRy per atom).

収録刊行物

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 59 (11), 1669-1676, 2018-11-01

  公益社団法人 日本金属学会

キーワード

• KKR-Green’s function method
• GGA
• Fermi-Dirac distribution
• real space cluster expansion for total energy
• phase stability
• Pd-rich PdRu alloys
• Pd-rich PdRh alloys

詳細情報

• CRID: 1390001288083574784
• NII論文ID: 40021711574
• NII書誌ID: AA1151294X
• DOI: 10.2320/matertrans.m2018194
• ISSN: 13475320
• ISSN: 13459678
• NDL書誌ID: 029321617
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I029321617
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/59/11/59_M2018194/_pdf
• 本文言語コード: en
• データソース種別:
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  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• 抄録ライセンスフラグ: 使用不可