First-principles study on stability, electronic, and mechanical properties of La-C and Ce-C binary compounds  

作　　者：Hui-ning Zhang Qiu-yan Wu Zhen-ying Hu Hui Li Hui-hui Xiong An-jun Xu 

机构地区：[1]School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi, China [2]Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China [3]Hubei Provincial Key Laboratory for New Processes of Iron making and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China [4]Ganhua Security Technology Co., Ltd., Nanchang 330001, Jiangxi, China [5]China Metallurgical Planning Net, Beijing 100711, China [6]School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China

出　　处：《Journal of Iron and Steel Research International》2019年第7期771-778,共8页

基　　金：This research was sponsored by the National Natural Science Foundation of China (Grant No. 51304053);Jiangxi University of Science and Technology Doctoral Start-up Fund (No. 3401223181);Jiangxi Provincial Education Department Project (GJJ170509);the Open Fund Project (FMRUlabl7-l, G201807) of Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology;This work was also supported by National Supercomputing Center in Shenzhen, China.

摘　　要：The phase stability and electronic and mechanical properties of rare earth (RE) carbides (La2C3, LaC2, Ce2C3, CeC2, and CeC) were investigated using first-principles calculations based on density functional theory. The calculated equilibrium lattice constants and cell volume agree well with available experimental data. The cohesive energy and formation enthalpy of these carbides show that they are thermodynamically and mechanically stable except LaC. The strong covalent bonding exists in these compounds, and the covalent bonds are mainly determined to be RE-C and C-C bonds. The hardness of RExCy compounds is less than 10 GPa, and the bulk modulus, shear modulus, and Young's modulus of Ce2C3 are the largest. The values of BIG (ratio of bulk modulus to shear modulus) and Poisson's ratio indicate that all the compounds have good ductility, and the ductility of CeC is larger than others. The Debye temperature of Ce2C3 is 429.67 K, which is the highest in those of experimental compounds.

关 键 词：RARE earth CARBIDE ELECTRONIC structure MECHANICAL property First PRINCIPLE 

分 类 号：TF[冶金工程]