稀土硼化物LaB_6晶体材料的弹性性质和力学性能  

Elastic and Mechanical Properties of Rare Earth Boride LaB_6 Crystalline Material

作　　者：张飞鹏 施加利 张静文[3] 包黎红[4] 秦国强 张光磊 杨新宇[3] 张久兴[3] ZHANG Feipeng;SHI Jiali;ZHANG Jingwen;BAO Lihong;QIN Guoqiang;ZHANG Guanglei;YANG Xinyu;ZHANG Jiuxing(Henan Provincial Engineering Laboratory of Building-Photovoltaics, Institute of Sciences, Henan University of Urban Construction, Pingdingshan 467036, China;School of Materials Sciences and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China;Anhui Provincial Key Laboratory of Advanced Functional Materials and Devices, College of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China;College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 010022, China)

机构地区：[1]河南城建学院数理学院建筑光伏一体化河南省工程实验室,河南平顶山467036 [2]石家庄铁道大学材料科学与工程学院,河北石家庄050043 [3]合肥工业大学材料科学与工程学院新型功能材料与器件安徽省重点实验室,安徽合肥230009 [4]内蒙古师范大学物理与电子信息学院,内蒙古呼和浩特010022

出　　处：《高压物理学报》2019年第2期45-49,共5页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(51572066;51302129;51662034);河南省科技计划项目(132300410071);河南省自然科学基金(162300410007)

摘　　要：利用密度泛函理论和Birch-Murnaghan物态方程,系统分析了LaB6晶体材料的弹性常数参数、体弹性模量、剪切弹性模量及其他力学性能。结果表明:LaB6晶体具有较大的弹性常数参数C11,说明在此主轴应力方向上具有较大的弹性常数;同时它还具有较大的体弹性模量,并且体弹性模量具有各向同性,剪切弹性模量具有各向异性;LaB6晶体的杨氏模量为227.85 GPa,泊松比为0.26,体剪弹性模量比值达到1.44,表明其脆性较强,不易发生弹性形变;LaB6晶体的硬度达到11.56 GPa,平均弹性波速达4.87 km/s。LaB6的带隙宽度为0.20 eV,呈金属性,内部电子具有较强的局域性,La和B之间具有较强的共价键成分。The elastic constants parameters, bulk modulus, shear modulus and mechanical properties of the LaB6 crystalline material have been systematically studied with density functional theory and the Birch- Murnaghan formation. The results show that the LaB6 has larger C11, indicating its larger elastic constant along this direction. The LaB6 also has large bulk modulus, and the bulk modulus is isotropic, whereas the shear modulus is moderately anisotropic. The LaB6 crystalline material has large Young’s modulus of 227.85 GPa, so it is hard for elastic deformation. The Poisson’s ratio is 0.26 and the B/G value is 1.44, these values indicate the moderate brittleness of this material. The hardness of LaB6 is 11.56 GPa and the mean elastic velocity is 4.87 km/s. The LaB6 has narrow band gap of 0.20 eV, showing that it is metallic type material. The electrons of LaB6 have strong localization interaction, and there is covalent bond between La and B.

关 键 词：LaB6 弹性性质 力学性能 弹性常数 

分 类 号：O521.2[理学—高压高温物理] TN34[理学—物理]