Phase Transition and Electronic Structures of All-d-Metal Heusler-Type X(2)MnTi Compounds (X = Pd, Pt, Ag, Au, Cu, and Ni).
Phase Transition and Electronic Structures of All-d-Metal Heusler-Type X(2)MnTi Compounds (X = Pd, Pt, Ag, Au, Cu, and Ni).
复制标题
全d-金属Heusler型X2MnTi化合物的相变和电子结构（X = Pd、Pt、Ag、Au、Cu和Ni）
DOI：
10.3389/fchem.2020.546947
复制
发表时间：
2020
影响因子：
5.5
通讯作者：
Wang X
中科院分区：
文献类型：
--
作者：
Wu M;Zhou F;Khenata R;Kuang M;Wang X
在这项工作中，我们用第一性原理研究了一些新设计的全金属Heusler化合物X2MnTi （X = Pd, Pt, Ag, Au， Cu和Ni）的相变和电子结构。研究了这些材料的XA和L21结构之间的竞争，发现X2MnTi倾向于具有L21型结构，这符合众所周知的位点偏好规则（SPR）。在L21结构下，我们研究了这些材料最稳定的磁性状态，我们发现铁磁性状态由于其能量较低而最稳定。通过四边形变形，我们发现L21结构不再是最稳定的结构，出现了更稳定的四边形L10结构。即在四方应变作用下，材料发生四方相变（即由立方L21结构向四方L10结构转变）。在计算态密度的基础上，详细讨论了L21-L10结构转变的机理。此外，我们发现L10和L21的最稳定相之间的能量差，定义为ΔEM （ΔEM = ecubic - etetronal），可以通过均匀应变来调节。最后，得到了X2MnTi （X = Pd, Pt, Ag, Au， Cu和Ni）的所有四方相的声子谱，为L10的稳定性提供了有力的证据。我们希望我们的研究能为今后的实验研究提供理论指导。
In this work, we investigated the phase transition and electronic structures of some newly designed all-d-metal Heusler compounds, X2MnTi (X = Pd, Pt, Ag, Au, Cu, and Ni), by means of the first principles. The competition between the XA and L21 structures of these materials was studied, and we found that X2MnTi favors to feature the L21-type structure, which is consistent with the well-known site-preference rule (SPR). Under the L21 structure, we have studied the most stable magnetic state of these materials, and we found that the ferromagnetic state is the most stable due to its lower energy. Through tetragonal deformation, we found that the L21 structure is no longer the most stable structure, and a more stable tetragonal L10 structure appeared. That is, under the tetragonal strain, the material enjoys a tetragonal phase transformation (i.e., from cubic L21 to tetragonal L10 structure). This mechanism of L21-L10 structure transition is discussed in detail based on the calculated density of states. Moreover, we found that the energy difference between the most stable phases of L10 and L21, defined as ΔEM (ΔEM = ECubic-ETetragonal), can be adjusted by the uniform strain. Finally, the phonon spectra of all tetragonal X2MnTi (X = Pd, Pt, Ag, Au, Cu, and Ni) phases are exhibited, which provides a powerful evidence for the stability of the tetragonal L10 state. We hope that our research can provide a theoretical guidance for future experimental investigations.
登录
查看更多内容
影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J
影响因子：
8.6
作者：
Alippi, P;Marcus, PM;Scheffler, M
通讯作者：
Scheffler, M
影响因子：
6.3
作者：
Hafner, J.
通讯作者：
Hafner, J.
影响因子：
4
作者：
Oikawa, K;Ota, T;Ishida, K
通讯作者：
Ishida, K
影响因子：
5.3
作者：
Cui, Zhou;Wu, Bo;Feng, Yu
通讯作者：
Feng, Yu