Mechanical, electronic and thermodynamic properties of C14-type AMg2 (A = Ca, Sr and Ba) compounds from first principles calculations
Mechanical, electronic and thermodynamic properties of C14-type AMg2 (A = Ca, Sr and Ba) compounds from first principles calculations
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根据第一性原理计算得出 C14 型 AMg2（A=Ca、Sr 和 Ba）化合物的机械、电子和热力学性质
DOI：
10.1016/j.commatsci.2014.10.005
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发表时间：
2015-02-01
影响因子：
3.3
通讯作者：
Zeng, Xiao-Qin
中科院分区：
文献类型：
--
作者：
Liu, Yong;Hu, Wen-Cheng;Zeng, Xiao-Qin
采用第一性原理方法，在广义梯度近似（GGA）下研究了C14型Laves相AMg（2）（A = Ca，Sr和Ba）的力学和热力学性质.我们的平衡晶格参数和生成焓的结果与以前的实验结果吻合得很好。特别地，我们讨论了这些相结构的热力学稳定性和机械各向异性。采用Voigt-Reuss-Hill算术近似法推导了多晶的弹性模量。随后，用Pugh准则（B/G）和泊松比来表征延性和脆性。此外，德拜温度计算从平均弹性波速度从体积和剪切模量。通过计算态密度和电荷密度差，揭示了电子结构的内在机制。最后，结合准谐波近似计算声子频率，预测了热力学性质随温度的变化。(C)© 2014 Elsevier B. V.保留所有权利。
Using first principles total energy calculations within the generalized gradient approximation (GGA), we have investigated the mechanical and thermodynamics properties of C14-type Laves phases AMg(2) (A = Ca, Sr and Ba). Our results of equilibrium lattice parameters and formation enthalpy agree closely with previous experimental results. In particular we have discussed the thermodynamic stabilities and mechanical anisotropies of these phase structures. The polycrystalline elastic moduli have been deduced by Voigt-Reuss-Hill arithmetic approximation. Subsequently, the ductility and brittleness are characterized with the estimation from Pugh's rule (B/G) and Poisson's ratio. Additionally, the Debye temperature is calculated from the average elastic wave velocity obtained from bulk and shear moduli. The calculations of density of states and charge density difference are performed to reveal the underlying mechanism of electronic structure. Finally, variations of thermodynamic properties with temperature are predicted by calculating phonon frequencies combined within the quasi-harmonic approximation. (C) 2014 Elsevier B.V. All rights reserved.