CeAuGa_(3)的力学性质及磁性的第一性原理计算  

Mechanical and magnetic properties of CeAuGa_(3) from first-principles calculations

作　　者：程耀世 刘本琼[1] CHENG Yao-Shi;LIU Ben-Qiong(Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621999,China)

机构地区：[1]中国工程物理研究院核物理与化学研究所,绵阳621999

出　　处：《四川大学学报（自然科学版）》2021年第5期111-117,共7页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金面上项目(11875238)。

摘　　要：本文基于第一性原理计算研究了铈基金属间化合物CeAuGa_(3)的结构性质与力学稳定性,获得了弹性常数、宏观弹性参数(包括体弹模量、剪切模量、杨氏模量、泊松比)以及声子色散曲线,结果表明I4mm结构不仅力学稳定,且动力学稳定.通过计算铈离子之间的自旋交换相互作用,我们分析了CeAuGa_(3)几种可能的有序自旋态,并发现该材料的基态可能是铁磁结构.位于ab面内的第一近邻和第二近邻的正(铁磁)交换耦合起主导作用,而位于相邻平面的铈离子之间的第三近邻铁磁相互作用则非常微弱.In this paper,the structural properties and the mechanical stability of Ce-based intermetallic CeAuGa_(3) are studied based on the first-principles calculations.The full sets of elastic constants,the associated macroscopic elastic parameters(bulk,shear and Young’s moduli,Poisson ratio),and phonon dispersion have been determined,indicating that the I4mm structure is both mechanically and dynamically stable.By calculating the spin exchange interaction between cerium ions,we have analyzed several possible ordered spin states of CeAuGa_(3),and found that the ground state of CeAuGa_(3) prefers to be ferromagnetic ordering.The positive(ferromagnetic)exchange couplings within each ab layer play a dominant role,while the third nearest neighbour ferromagnetic interaction between adjacent ab layers of Ce ions is relatively weak.

关 键 词：弹性常数 自旋交换相互作用 声子色散 第一性原理计算 

分 类 号：O469[理学—凝聚态物理]