IrB和IrB_2力学性质的第一性原理计算  

First-principles calculations of the mechanical properties of IrB and IrB_2

作　　者：曾小波[1] 朱晓玲[2] 李德华[1] 陈中钧[3] 艾应伟[4] 

机构地区：[1]四川师范大学物理与电子工程学院,成都610066 [2]成都学院电子信息工程学院,成都610106 [3]电子科技大学物理电子学院,成都610054 [4]四川大学生命科学学院,成都610064

出　　处：《物理学报》2014年第15期77-84,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:41171175);四川省高校科研创新团队基金(批准号:12TD008)资助的课题~~

摘　　要：采用平面波赝势密度泛函理论对0—100 GPa静水压下P1-IrB(空间群Pnma)和P5-IrB2(空间群Pmmn)结构的平衡态晶格常数、弹性常数等性质进行了研究.研究结果表明,P1-IrB不可压缩性随着压强的增加而增强;P5-IrB2结构在0—100 GPa范围内弹性常数、体弹模量、剪切模量均呈现出有规律的变化,当所加压强为50 GPa时,杨氏模量和在b方向的晶格常数发生异常变化.对零压下P1-IrB和P5-IrB2的电子结构的研究发现,二者均没有一个明显的带隙,主要原因为Ir原子和B原子间的共价作用.从P1-IrB和P5-IrB2的能带结构和态密度图可以发现这两种结构均有金属性.We have employed ab-initio plane-wave pseudopotential density functional theory to calculate the equilibrium lattice parameters, elastic constants, under the hydrostatic pressures from 0 to 100 GPa for P1-IrB with Pnma space group and P5-IrB2 with Pmmn structures. Results show that the P1-IrB structure is stable, and the incompressibility is enhanced with the increase of pressure. And the elastic constants, bulk modulus, shear modulus for P5-IrB2 structure exhibit the regular changes under the hydrostatic pressures from 0 to 100 GPa. But when the pressure becomes 50 GPa, the Young＇s modulus and the lattice constant in the direction b for P s-IrB2 structure will change exceptionally. Results show that both are not of obvious band gaps in P1-IrB and P5-IrBa electronic structures under zero pressure, because of the covalent effect between Ir and B atoms. The analysis of band structure and the figure of density of states for P1-IrB and P5-IrB2 indicate that the two kinds of structure have metal properties.

关 键 词：P1-IrB P5-IrB2 第一性原理 力学性质 

分 类 号：O561[理学—原子与分子物理]