Al_4Ce和Al_2CeZn_2相弹性性能的第一性原理研究  

An Initio Study of Elastic Properties of Al_4Ce and Al_2CeZn_2 Phases

作　　者：赵沙斐 潘荣凯[1] 周思晨 罗涛朋 吴东海[1] 

机构地区：[1]广西大学化学化工学院,广西壮族自治区南宁530004

出　　处：《郑州大学学报（工学版）》2014年第2期104-107,共4页Journal of Zhengzhou University（Engineering Science）

基　　金：国家自然科学基金资助项目(51071053)

摘　　要：运用第一性原理研究了Al4Ce和Al2CeZn2相的结构和弹性性能.结果显示:随着部分Al被Zn取代,Al2CeZn2的晶格常数a减小,c增大,且Al2CeZn2形成焓更低,热力学稳定性更高.除了C66,Al2CeZn2的弹性常数Cij都比Al4Ce小.相应地,Al2CeZn2的体积模量和剪切模量也较低,表明外加应力下体积形变和对剪切形变阻力更小.尽管两种相都是脆性的,Al2CeZn2比Al4Ce更软.Al2CeZn2的弹性各向异性比Al4Ce小.还研究了电子结构以揭示Al2CeZn2和Al4Ce弹性性能的内在机理.Elastic properties of Al4Ce and Al2CeZn2 phases have been studied within density functional theory framework.With substitution of Zn for part Al,the lattice constant a of Al2CeZn2 is reduced while c is increased.Al2 CeZn2 is thermodynamically more stable due to the lower formation enthalpy.With the exception of C66,Cij of Al2CeZn2 is smaller than one of Al4Ce.Due to the lower bulk and shear moduli,Al2CeZn2 has the lower resistance to volume change under applied pressure and the smaller resistance to shear deformation against external forces.Al2CeZn2 is more ductile than Al4Ce although both two phases behave as brittle materials.Furthermore,the elastic anisotropy of Al2CeZn2 is smaller than that of Al4Ce.Also,the Debye temperature has been calculated.The electronic structures are further investigated to uncover the underlying mechanism for elastic properties of Al2CeZn2 and Al4Ce.

关 键 词：Al2CeZn2 Al4Ce 结构稳定性 弹性性能 电子结构 

分 类 号：O34[理学—固体力学]