Intrinsic instability to martensite phases in ferromagnetic shape memory alloy Ni2MnGa: Quasiparticle self-consistent GW investigation
Intrinsic instability to martensite phases in ferromagnetic shape memory alloy Ni2MnGa: Quasiparticle self-consistent GW investigation
复制标题
铁磁形状记忆合金 Ni2MnGa 中马氏体相的本质不稳定性：准粒子自洽引力场研究
DOI：
10.1103/physrevmaterials.7.024413
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发表时间：
2023
影响因子：
3.4
通讯作者：
Oda Tatsuki
中科院分区：
文献类型：
--
作者：
Obata Masao;Kotani Takao;Oda Tatsuki
利用准粒子自洽方法研究了铁磁形状记忆合金的电子结构，该方法考虑了电子局域化效应，无需经验参数。通过与广义梯度近似的密度泛函方法的比较，发现导致马氏体相变的立方相的Ni轨道位于费米能级上，这意味着带Jahn-Teller（JT）效应的明确起源.从立方相的广义磁化率的分析，负责调制结构的10 M，14 M，和6 M的不稳定性被发现是一个内在的性质的电子状态。这些状态可以稳定调制的一个，伴随着四倍的本地JT失真。它们的费米面嵌套的性质敏感地依赖于磁矩的微妙变化，对应于调制结构出现依赖于温度和磁性元件的组成的实验事实。讨论了与纳米孪晶边界的调制排列有关的沿[110]方向沿着的次级嵌套矢量。
We investigated the electronic structure of a ferromagnetic shape memory alloyutilizing an advanced approach, quasiparticle self-consistent, which takes account of electron localization effects without empirical parameters. The Niorbitals in the cubic phase, which lead to martensite phase transition, were found to locate on the Fermi level, implying a clear definitive origin of band Jahn-Teller (JT) effect in comparison with the results obtained by the density functional approach of generalized gradient approximation. From the analysis of generalized susceptibility in the cubic phase, the instabilities responsible for the modulated structures of 10M, 14M, and 6M were found to be an intrinsic property in the electronic states. These states may stabilize the modulated one, accompanied by tetragonal local JT distortions. Their property of Fermi surface nesting sensitively depends on a subtle change in the magnetic moment, corresponding to the experimental fact that the modulated structure appears depending on temperature and the composition of the magnetic element. The secondary nesting vector along [110] direction was discussed in relation to a modulation alignment of the nanotwin boundary.