First-Principles Calculations of Elastic and Thermal Properties of Lanthanum Hexaboride  

作　　者：徐国亮 陈敬东 夏要争 刘雪峰 刘玉芳 张现周 

机构地区：[1]College of Physics and Information Engineering, Henan Normal University, Xinxiang 453007 [2]College of Physics and Electronic Engineering, Xinyang Normal University, Xinyang 464000

出　　处：《Chinese Physics Letters》2009年第5期179-182,共4页中国物理快报（英文版）

基　　金：Supported by the Basic Research Program of Education Bureau of Henan Province under Grant Nos 072300410130 and 2008A140006, and the National Natural Science Foundation of China under Grant No 10774039.

摘　　要：The plane-wave pseudopotentiai method using the generaiized gradient approximation within the framework of density functional theory is applied to anaylse the bulk modulus, thermal expansion coefficient and heat capacity of LaB6. The quasi-harmonic Debye model, using a set of total energy versus volume obtained with the plane-wave pseudopotential method, is applied to the study of the thermal properties and vibrationai effects. We analyse the bulk modulus of LaB6 up to 1500 K. The elastic properties calculations show that our system is mechanically stable. For the heat capacity and the thermal expansion, significant differences in properties are observed above 300K. The calculated zero pressure bulk modulus is in good agreement with the experimental data. Moreover, the Debye temperatures are determined from the non-equilibrium Gibbs functions and compared to available data.The plane-wave pseudopotentiai method using the generaiized gradient approximation within the framework of density functional theory is applied to anaylse the bulk modulus, thermal expansion coefficient and heat capacity of LaB6. The quasi-harmonic Debye model, using a set of total energy versus volume obtained with the plane-wave pseudopotential method, is applied to the study of the thermal properties and vibrationai effects. We analyse the bulk modulus of LaB6 up to 1500 K. The elastic properties calculations show that our system is mechanically stable. For the heat capacity and the thermal expansion, significant differences in properties are observed above 300K. The calculated zero pressure bulk modulus is in good agreement with the experimental data. Moreover, the Debye temperatures are determined from the non-equilibrium Gibbs functions and compared to available data.

分 类 号：O641.121[理学—物理化学] V512[理学—化学]