RMn_(12-x)Fe_x(R=Y,Ho,Er)择优占位和晶格振动的原子级模拟(英文)  

Site preference and vibrational properties of RMn_(12-x)Fe_x(R=Y,Ho,Er)

作　　者：钱萍[1] 田惠军[1] 苏伟[1] 

机构地区：[1]北京化工大学理学院

出　　处：《周口师范学院学报》2007年第5期56-63,共8页Journal of Zhoukou Normal University

基　　金：Supported by the National 973 Project TG2000067101 and TG2000067106.

摘　　要：利用基于第一性原理和陈氏晶格反演方法获得的原子间相互作用对势模拟计算了RMn12-xFex(R=Y,Ho,Er)金属间化和物的结构性质,计算结果表明第三组元Fe择优占据8f晶位,8j晶位与8i晶位次之,计算的晶格常数与实验结果符合较好.利用晶格反演的原子间相互作用对势对RMn12-xFex复杂结构的一些力学性质如弹性常数和体模量进行了模拟计算,并首次探讨了该体系的声子态密度曲线及德拜温度.Crystal structure of intermetallics RMn12-xFex（R= Y, Ho, Er） is simulated by using pair potentials based on ab initio method and lattice inversion technique. Calculated results show that Fe atom preferentially substitutes for Mn in the 8f site and randomly substitutes in the 8j and 8i site of the lattice. The calculated lattice constants are in good agreement with the experimental values. Further, some simple mechanical properties such as the elastic constants and bulk modulus are investigated for these materials. In addition, phonon densities of states are also evaluated for RMn12-xFex compounds with the tetragonal ThMn12-type structure.

关 键 词：原子间相互作用势 择优占位 晶格动力学 

分 类 号：O733.1[理学—晶体学]