Ab initio calculations of the mechanical and acoustic properties of Ti-2-based Heusler alloys under pressures
Ab initio calculations of the mechanical and acoustic properties of Ti-2-based Heusler alloys under pressures
复制标题
Ti-2 基 Heusler 合金在压力下的机械和声学性能的从头算
DOI：
10.1140/epjb/e2018-90261-y
复制
发表时间：
2018
影响因子：
1.6
通讯作者：
Wen YF
中科院分区：
文献类型：
--
作者：
Wen Yufeng;Yu Xiaoguang;Ye Yuanxiu;Wu Donglan;Gou Qingdong;Wen Yufeng;Zeng Xianshi;Wen YF;Wen YF
利用从头算结合均匀变形理论计算得到的Ti2NiZ（Z= Al，Ga，In）Heusler合金的二阶和三阶弹性常数，研究了不同压力下合金的力学和声学性能.结果表明，随着压力的增加，三种合金的力学稳定性降低，而塑性提高。随着压力的增加，除了Ti2NiGa和Ti2NiIn在110 Ω方向上的横向声速外，这些合金的声速都增加。德拜温度和最小热导率也预测在所获得的声速，这增加了所有三种合金的压力。计算得到的晶格常数、带隙和二阶弹性常数与理论值吻合较好。
The mechanical and acoustic properties of Ti2NiZ(Z= Al, Ga and In) Heusler alloys under different pressures were studied based on the second- and third-order elastic constants obtained by the ab initio calculations combined with homogeneous deformation theory. The results showed that the mechanical stability is reduced while the ductility is improved with increasing pressure for all three alloys. As the pressure increases, the acoustic velocities of these alloys increase except for the transverse acoustic velocities in ⟨110⟩ direction of Ti2NiGa and Ti2NiIn. The Debye temperature and minimum thermal conductivity were also predicted in terms of the obtained acoustic velocities, which increase with increasing pressure for all three alloys. The calculated lattice constants, band gaps and second-order elastic constants were in agreement with the available theoretical values.