TaC和Ta_2C结构稳定性、电子结构及力学性能的研究  

A theoretical study of structure stability,electronic and mechanical properties of TaC and Ta_2C

作　　者：马淑红[1] 焦照勇[1] 黄肖芬[2] 张现周[1] 

机构地区：[1]河南师范大学物理与电子工程学院,新乡453007 [2]四川师范大学物理与电子工程学院,成都610101

出　　处：《原子与分子物理学报》2014年第1期149-154,共6页Journal of Atomic and Molecular Physics

基　　金：河南省自然科学基金(132300410017);教育部科学技术研究重点项目(212104)

摘　　要：采用基于密度泛函理论的平面波超软赝势方法对TaC和Ta2C的结构及结构稳定性、电子结构和力学性能进行了系统地分析和研究.研究结果表明:TaC的最稳定结构为岩盐构型(RS-TaC),而Ta2C在零压下的最稳定结构为C6-Ta2C,随着外压力的增大,在23.5GPa处最稳定结构转变为L′3-Ta2C.同时还计算分析了TaC和Ta2C稳定结构的电子结构特征,解释了该材料具有优异力学性能的微观机制,并计算分析了外压力对其力学性能的影响.The structure stability, electronic and mechanical properties of TaC and Ta2C compounds are studied in detail based on the first-principle calculations. The calculated results indicate that RS-TaC and C6-Ta2C are the most stable structures among all the considered phases, and the high mechanical hardness of these compounds can be ascribed to a strong covalent bond between Ta and C atoms. Moreover, the related mechanical properties between TaC and Ta2 C compounds are compared and Ta2 C is shown to be a ductile material under considered pressures, while TaC exhibits a transition from brittleness to ductility.

关 键 词：过渡金属碳化物 力学性能 第一性原理计算 

分 类 号：O482[理学—固体物理] O521.2[理学—物理]