中国物理B ›› 2012, Vol. 21 ›› Issue (7): 77102-077102.doi: 10.1088/1674-1056/21/7/077102

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Structural, elastic, phonon, and electronic properties of MnPd alloy

王俊斐, 陈文周, 姜振益, 张小东, 司良   

  1. Institute of Modern Physics, Northwest University, Xi'an 710069, China
  • 收稿日期:2012-01-07 修回日期:2012-04-05 出版日期:2012-06-01 发布日期:2012-06-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10647008 and 50971099) and the Research Fund for the Doctoral Program of Higher Education, China (No. 20096101110017).

Structural, elastic, phonon, and electronic properties of MnPd alloy

Wang Jun-Fei(王俊斐), Chen Wen-Zhou(陈文周), Jiang Zhen-Yi(姜振益)†, Zhang Xiao-Dong(张小东), and Si Liang(司良)   

  1. Institute of Modern Physics, Northwest University, Xi'an 710069, China
  • Received:2012-01-07 Revised:2012-04-05 Online:2012-06-01 Published:2012-06-01
  • Contact: Jiang Zhen-Yi E-mail:jiangzy@nwu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10647008 and 50971099) and the Research Fund for the Doctoral Program of Higher Education, China (No. 20096101110017).

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摘要： The structural, elastic, phonon, and electronic properties of MnPd alloy have been investigated by using the first-principles calculations. The calculated lattice constants and electronic structure are in good agreement with the experimental results. The microscopic mechanism of the diffusionless martensitic transition from the paramagnetic B2 (PM-B2) phase to the antiferromagnetic L10 (AFM-L10) phase through the intermediate paramagnetic L10 (PM-L10) phase has been explored theoretically. The obtained negative shear modulus C′= (C11-C12)/2 of the PM-B2 phase is closely related to the instability of the cubic B2 phase with respect to the tetragonal distortions. The calculated phonon dispersions for PM-L10 and AFM-L10 phases indicate that they are dynamically stable. However, the AFM-L10 phase is energetically most favorable according to the calculated total energy order, so the PM-L10 !AFM-L10 transition is caused by the magnetism rather than the electron–phonon interaction. Additionally, the AFM-L10 state is stabilized through the formation of a pseudo gap located at the Fermi level. The calculated results show that the CuAu-I type structure in the collinear antiferromagnetic state is dynamically and mechanical stable, thus is the low temperature phase.

关键词: transition metals and alloys, density functional theory, band structure, elasticity

Abstract: The structural, elastic, phonon, and electronic properties of MnPd alloy have been investigated by using the first-principles calculations. The calculated lattice constants and electronic structure are in good agreement with the experimental results. The microscopic mechanism of the diffusionless martensitic transition from the paramagnetic B2 (PM-B2) phase to the antiferromagnetic L10 (AFM-L10) phase through the intermediate paramagnetic L10 (PM-L10) phase has been explored theoretically. The obtained negative shear modulus C′= (C11-C12)/2 of the PM-B2 phase is closely related to the instability of the cubic B2 phase with respect to the tetragonal distortions. The calculated phonon dispersions for PM-L10 and AFM-L10 phases indicate that they are dynamically stable. However, the AFM-L10 phase is energetically most favorable according to the calculated total energy order, so the PM-L10 !AFM-L10 transition is caused by the magnetism rather than the electron–phonon interaction. Additionally, the AFM-L10 state is stabilized through the formation of a pseudo gap located at the Fermi level. The calculated results show that the CuAu-I type structure in the collinear antiferromagnetic state is dynamically and mechanical stable, thus is the low temperature phase.

Key words: transition metals and alloys, density functional theory, band structure, elasticity

中图分类号:  (Transition metals and alloys)

  • 71.20.Be