Theoretical study on the stability, elasticity, hardness and electronic structures of W-C binary compounds
Theoretical study on the stability, elasticity, hardness and electronic structures of W-C binary compounds
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W-C二元化合物稳定性、弹性、硬度及电子结构的理论研究
DOI：
10.1016/j.jallcom.2010.04.184
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发表时间：
2010-07-16
影响因子：
6.2
通讯作者：
Xu, Leilei
中科院分区：
文献类型：
--
作者：
Li, Yefei;Gao, Yimin;Xu, Leilei
本文采用第一性原理计算方法研究了W-C二元化合物（h-WC，c-WC，alpha-W_2C，beta-W_2C，gamma-W_2C，epsilon-W_2C）的基态性质。计算了各相的生成焓和内聚能。计算的弹性常数满足Born-Huang的稳定性准则，表明所有研究的化合物是机械稳定的。本文研究的所有W-C化合物都表现出比许多其他二元类型的碳化物，如Fe_3C，Cr_7C_3，Cr_3C和TiC更大的体积模量值。使用基于Simunek的工作的理论方法，估计晶体的硬度。计算并讨论了这些化合物的电子结构。应用Stoner的巡游磁性极化理论解释了化合物的顺磁行为。此外，还根据弹性和德拜温度的知识计算了每种化合物的热容。(C)2010 Elsevier B. V.保留所有权利。
The ground state properties of W-C binary compounds (h-WC, c-WC, alpha-W2C, beta-W2C, gamma-W2C, epsilon-W2C) are studied in this paper by using first-principles calculations. Formation enthalpy and cohesive energy for each phase are calculated. The calculated elastic constants satisfy the Born-Huang's stability criterion, indicating all studied compounds are mechanically stable. All W-C compounds studied in this paper exhibit larger bulk modulus values than many other binary types of carbide such as Fe3C, Cr7C3, Cr3C, and TiC. Using a theoretical method based on the works of Simunek, the hardness of the crystal is estimated. The electronic structures of these compounds are calculated and discussed. Stoner's polarization theory for itinerant magnetism is applied to explain the observed paramagnetic behavior of the compounds. Moreover, the heat capacity is also calculated for each compound based on the knowledge of the elasticity and Debye temperature. (C) 2010 Elsevier B.V. All rights reserved.