钙钛矿型ScRh_3X(X=B,C,N)的第一性原理研究  

First-principles calculations on perovskite-type ScRh_3X (X=B,C and N)

作　　者：王志斌[1] 周艳萍[2] 张志超[1] 郝险峰[1] 

机构地区：[1]燕山大学环境与化学工程学院,河北秦皇岛066004 [2]燕山大学继续教育学院,河北秦皇岛066004

出　　处：《燕山大学学报》2009年第4期304-307,318,共5页Journal of Yanshan University

基　　金：国家自然科学基金资助项目(50672080)

摘　　要：利用第一性原理研究了钙钛矿型的ScRh3X(X=B,C,N)及其固溶体的结构、弹性、电子性质等。研究结果表明,对于平衡状态下的ScRh3BC1(0<<1)固溶体,其结构参数和已知的实验数据相一致,和ScRh3C结构相比,在0<<1的范围内,固溶体ScRh3BC1的体积弹性模量和弹性常数44随着价电子浓度的增加增大,而剪切模量却表现出单调下降的趋势。本文根据计算得到的电子结构信息对这些现象进行了分析,发现剪切模量比体积弹性模量或44能更好的预测该体系的硬度。The structural, elastic and electronic properties ofperovskite-type ScRh3X （X = B, C and N） and their solid solutions were investigated by first-principles calculations. The calculated equilibrium structural parameters of ScRh3BxC1-x （0≤x≤1） solutions are in agreement with the available experimental data. As the valence electron concentration increases, the bulk modulus and C44 achieve maximum in the middle range corresponding to ScRh3C, while the shear modulus decreases monotonically in the whole range. These trends can be understood based on the electronic structure analysis. More important, the results suggested that the shear modulus is a better hardness predicator rather than the bulk modulus and C44 for these compounds.

关 键 词：钙钛矿 第一性原理 体积弹性模量 剪切模量 电子结构 

分 类 号：O611[理学—无机化学]