Anharmonicity of the lattice vibration in shape memory alloys: quantitative analyses based on first-principles calculations

• Project/Area Number: 16K18228
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Physical properties of metals/Metal-base materials
• Research Institution: Kyoto University
• Principal Investigator: Ikeda Yuji 京都大学, 大学院工学研究科, 特定助教 (90710450)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2016: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: 形状記憶合金 / 第一原理計算 / 格子振動（フォノン） / 不規則合金 / 非調和効果 / フォノン / 分子動力学法 / マルテンサイト変態温度

Outline of Final Research Achievements

We formulate and implement a first-principles-based method to analyze the lattice vibration in disordered alloys to elucidate the lattice vibrational properties of shape memory alloys with nonstoichiometric composition ratios and its contribution to the order-disorder transition. We apply this method to various models of disordered alloys including high-entropy alloys and found characteristic behaviors in their phonon spectra such as peak broadening and peak discontinuity. We also found from the analysis on magnetic disordered alloys that the phonon spectra largely depend on the magnetic states of the alloys. We furthermore analyze the force constants in disordered alloys in detail and elucidate its dependences on element-pairs and on interatomic distances.

Research Products

• [Int'l Joint Research] Max-Planck Institut fuer Eisenforschung(ドイツ)
• [Journal Article] Temperature-dependent phonon spectra of magnetic random solid solutions (2018)
  • Author(s): Ikeda, Y, Kormann, F, Dutta, B, Carreras, A, Seko, A, Neugebauer, J and Tanaka, I
  • Journal Title: NPJ COMPUTATIONAL MATERIALS Volume: 4 Issue: 1 Pages: 7-7
  • DOI: 10.1038/s41524-018-0063-1
  • NAID: 120006523830
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Phonon broadening in high entropy alloys (2017)
  • Author(s): Koermann Fritz、Ikeda Yuji、Grabowski Blazej、Sluiter Marcel H. F.
  • Journal Title: npj Computational Materials Volume: 3 Issue: 1 Pages: 36-36
  • DOI: 10.1038/s41524-017-0037-8
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First-principles screening of structural properties of intermetallic compounds on martensitic transformation (2017)
  • Author(s): Lee, J, Ikeda, Y, and Tanaka I
  • Journal Title: NPJ COMPUTATIONAL MATERIALS Volume: 3 Issue: 1 Pages: 52-52
  • DOI: 10.1038/s41524-017-0053-8
  • Peer Reviewed / Open Access
• [Journal Article] Mode decomposition based on crystallographic symmetry in the band-unfolding method (2017)
  • Author(s): Yuji Ikeda, Abel Carreras, Atsuto Seko, Atsushi Togo, and Isao Tanaka
  • Journal Title: PHYSICAL REVIEW B Volume: 95 Issue: 2 Pages: 024305-024305
  • DOI: 10.1103/physrevb.95.024305
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Phonon-Band Unfolding for Disordered Crystalline Systems (2016)
  • Author(s): Yuji Ikeda
  • Organizer: The 19th Asian workshop on First-Principles Electronic Structure Calculations (ASIAN-19)
  • Place of Presentation: National Chiao Tung University, Hsinchu, Taiwan
  • Year and Date: 2016-11-01
  • Int'l Joint Research
• [Presentation] Phonon dispersion relations of disordered alloys using the band-unfolding method (2016)
  • Author(s): Yuji Ikeda, Abel Carreras, Atsuto Seko, Atsushi Togo, and Isao Tanaka
  • Organizer: Ab initio Description of Iron and Steel: Mechanical Properties (ADIS2016)
  • Place of Presentation: Ringberg Castle, Rottach-Egern, Germany
  • Year and Date: 2016-10-03
  • Int'l Joint Research
• [Presentation] Band-unfolding法を用いた不規則合金のフォノン分散関係の解析 (2016)
  • Author(s): 池田 裕治，Abel Carreras, 世古 敦人，東後 篤史，田中 功
  • Organizer: 日本金属学会２０１７年秋期講演大会（第１５９回）
  • Place of Presentation: 大阪大学 豊中キャンパス
  • Year and Date: 2016-09-22
• [Presentation] Dynamical Stability of Shape Memory Alloys from First-Principles (2016)
  • Author(s): Yuji Ikeda, Abel Carreras, Atsushi Togo, and Isao Tanaka
  • Organizer: 5th International Conference on Ferromagnetic Shape Memory Alloys (ICFSMA’16)
  • Place of Presentation: Hotel Metropolitan Sendai, Sendai, Japan
  • Year and Date: 2016-09-06
  • Int'l Joint Research
• [Presentation] Phonon Band-Unfolding for Disordered Alloys Based on First-Principles (2016)
  • Author(s): Yuji Ikeda, Atsuto Seko, Atsushi Togo, and Isao Tanaka
  • Organizer: 9th Pacific Rim International Congress on Advanced Materials and Processing (PRICM-9)
  • Place of Presentation: Kyoto International Conference Center, Sendai, Japan
  • Year and Date: 2016-08-03
  • Int'l Joint Research
• [Presentation] Unfolding of Phonon Modes of Disordered Alloys: a First-Principles Study (2016)
  • Author(s): Yuji Ikeda, Atsuto Seko, Atsushi Togo, and Isao Tanaka
  • Organizer: The 5th International Symposium on Advanced Microscopy and Theoretical Calculations (AMTC5)
  • Place of Presentation: WINC AICHI, Nagoya, Japan
  • Year and Date: 2016-05-11
  • Int'l Joint Research