First-principles study on the mechanical, vibrational and thermodynamic characteristics of intermetallic compound Ni2Ta
First-principles study on the mechanical, vibrational and thermodynamic characteristics of intermetallic compound Ni2Ta
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金属间化合物Ni2Ta力学、振动和热力学特性的第一性原理研究
DOI：
10.1016/j.physb.2019.411888
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发表时间：
2020
影响因子：
2.8
通讯作者：
Chen Liyi
中科院分区：
文献类型：
--
作者：
Zhang Chuanfeng;Yuan Jinke;Ye Changwen;Liao Bing;Zhang Zhiting;Xiang Hang;Chen Liyi
采用密度泛函理论对Ni 2 Ta的力学、振动和热力学性质进行了系统的研究。完全弛豫的结构参数与已有的实验测量数据和已发表的理论结果吻合较好。得到了单晶弹性常数、多晶弹性模量、泊松比σ和维氏硬度H-nu。通过绘制剪切模量和杨氏模量的三维表面等值线，研究了各向异性特征。利用有限位移法，首次报道了声子色散曲线和声子态密度。对γ点的红外和拉曼声子模进行了归属和讨论。最后，利用声子态密度预测了体系的等容比热容C-nu和德拜温度θ（D）等热力学特性。基于这些优异的性能，Ni 2 Ta有望成为一种具有高温和耐腐蚀性能的金属间化合物。
The mechanical, vibrational and thermodynamic characteristics of Ni2Ta were systematically investigated by means of density functional theory. The fully relaxed structure parameters were agreed well with the available experimental measured datas and published theoretical results. The single crystal elastic constants , poly-crystalline modulus, Possion's ratio sigma and Vickers hardness H-nu were obtained. The anisotropic characters were studied by plotting the 3D surface contour of shear modulus and Young's modulus. Using the finite displacement method, the phonon dispersion curves and the phonon density of states were reported for the first time. The infrared-active and Raman phonon modes at the Gamma point were assigned and discussed. Finally, the thermodynamic characteristics such as isochoric specific heat capacities C-nu and Debye temperature theta(D) were predicted by the phonon density of states. Based on these exceptional properties, it was expected that Ni2Ta could be a promising intermetallic compound with high temperature and corrosion resistant performance.