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

The structural, elastic, phonon and electronic properties of a MnPd alloy have been investigated using the first- principles calculation. The calculated lattice constants and electronic structure agree well with the experimental results. The microscopic mechanism of the diffusionless martensitic tra...

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Published inChinese physics B Vol. 21; no. 7; pp. 450 - 454
Main Author 王俊斐 陈文周 姜振益 张小东 司良
Format Journal Article
LanguageEnglish
Published 01.07.2012
Subjects
Antiferromagnetism
Dispersions
Elastic constants
Electronic properties
Fermi level
Instability
Mathematical analysis
Phase transformations
Phonons
原子力显微镜
合金
声子
弹性
电子性质
电子结构
第一原理计算
马氏体相变
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ISSN1674-1056
2058-3834
1741-4199
DOI10.1088/1674-1056/21/7/077102

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Summary:The structural, elastic, phonon and electronic properties of a MnPd alloy have been investigated using the first- principles calculation. The calculated lattice constants and electronic structure agree well 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 the 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 mechanically stable, thus is the low temperature phase.
Bibliography:Wang Jun-Fei, Chen Wen-Zhou, Jiang Zhen-Yi Zhang Xiao-Dong, and Si LiangInstitute of Modern Physics, Northwest University, Xi＇an 710069, China
The structural, elastic, phonon and electronic properties of a MnPd alloy have been investigated using the first- principles calculation. The calculated lattice constants and electronic structure agree well 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 the 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 mechanically stable, thus is the low temperature phase.
11-5639/O4
transition metals and alloys, density functional theory, band structure, elasticity
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1674-1056
2058-3834
1741-4199
DOI:10.1088/1674-1056/21/7/077102