Electronic structure, magnetic properties and martensitic transformation of Ga2MnTM (TM = Sc, Y, Lu) Heusler alloys
Electronic structure, magnetic properties and martensitic transformation of Ga2MnTM (TM = Sc, Y, Lu) Heusler alloys
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DOI：
10.1016/j.jmmm.2021.167891
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发表时间：
2021-07
影响因子：
2.7
通讯作者：
Yong Li;Liang Qin;Siyuan Huang;Xiaoming Zhang;Lingwei Li
中科院分区：
文献类型：
--
作者：
Yong Li;Liang Qin;Siyuan Huang;Xiaoming Zhang;Lingwei Li
用第一性原理计算方法研究了Ga 2基Heusler合金Ga 2 MnTM（TM= Sc，Y，Lu）的原子占位、电子结构、磁性和马氏体相变。对于立方相的三种合金，L21型结构比XA型结构更稳定，并且在每个平衡晶格常数下的磁性状态为亚铁磁（亚铁磁）。由于Mn原子的强交换劈裂，总磁矩主要由Mn原子贡献。对于Ga_2MnY和Ga_2MnLu，随着晶体常数的增加，铁磁（FM）态和非铁磁态之间的磁性状态交替出现。考虑立方相Ga_2 Mn_TM（TM= Sc，Y，Lu）的四重畸变，通过适当的热力学驱动力（ΔE为负值）和c/a，结合声子谱分析，可以得到潜在的马氏体相变。能量极小值分别位于c/a = 1.29，1.21，1.27处。三种合金在马氏体状态下的总磁矩随c/a的变化呈现出不同的变化规律，但仍保持马氏体状态。马氏体相变和丰富的磁态变化促使研究人员进一步探索新的Z2基Heusler合金。
The atomic site occupation, electronic structure, magnetism, martensitic transformation of Ga2-based Heusler alloys Ga2MnTM(TM= Sc, Y, Lu) have been investigated by first-principles calculations. For three alloys in cubic phase, the L21-type structure is more stable than XA-type structure, and the magnetic state is ferrimagnetic (FIM) at each equilibrium lattice constant. The total magnetic moments are mainly contributed by Mn atoms due to its strong exchange splitting. For Ga2MnY and Ga2MnLu, the magnetic states between ferromagnetic (FM) state and FIM state alternately appear with increasing crystal constant. Potential martensitic transformation can be gained due to the proper thermodynamic driving force (negative values of ΔE) and c/a, together with the analysis of phonon spectra, by considering the tetragonal distortions of cubic Ga2MnTM(TM= Sc, Y, Lu). The energy minima locate at c/a = 1.29, 1.21, 1.27, respectively. The three alloys in martensitic state show different variations of total magnetic moments and still maintain FIM state with changing c/a. The martensitic transformation and abundant changes in magnetic states motivate researchers to further explore new Z2-based Heusler alloys.