Stability and elastic properties of B2 CoX (X = Ti, Zr and Hf) intermetallic compounds as a function of pressure
Stability and elastic properties of B2 CoX (X = Ti, Zr and Hf) intermetallic compounds as a function of pressure
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DOI：
10.1080/14786435.2017.1400701
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发表时间：
2018-01
影响因子：
1.6
通讯作者：
Wen-fei Lu;Caiju Li;J. Yi;Kuangran Li
中科院分区：
文献类型：
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作者：
Wen-fei Lu;Caiju Li;J. Yi;Kuangran Li
摘要采用第一性原理方法，在广义梯度近似（GGA）下研究了考克斯（X = Ti，Zr和Hf）化合物的相稳定性、弹性性质和电子结构随压力的变化。形成能表明，在不同压力下，CoTi是这三种B2相中最稳定的相。通过Voigt-Reuss-Hill（弗赫）近似计算的B2 Co（X = Ti、Zr和Hf）的弹性性质随着压力的增加而增加。力学各向异性的特征在于通用各向异性指数（Au）和齐纳各向异性指数（AZ）。声速，德拜温度和熔化温度下施加的压力也进行了评估。电子结构表明，在压力作用下，电荷分布的变化是适度的，导致X（X = Ti，Zr和Hf）与Co之间成键的一般特征保持不变。
Abstract By means of first-principles calculations within the generalised gradient approximation (GGA), phase stability, elastic properties and electronic structures of B2 CoX (X = Ti, Zr and Hf) compounds as a function of pressure have been investigated. The formation energy indicates that CoTi is the most stable phase in these three B2 phases under different pressures. The elastic properties of B2 Co (X = Ti, Zr and Hf), calculated via the Voigt–Reuss–Hill (VRH) approximation, increase with increasing pressure. The mechanical anisotropies are characterised by the universal anisotropy index (AU) and the Zener anisotropy index (AZ). The sound velocities, Debye temperatures and melting temperature under applied pressure are also evaluated. Electronic structure show that the changes in the charge distribution are moderate under applied pressure, resulting in the general characteristics of the bonding between X (X = Ti, Zr and Hf) and Co remain unchanged.