Al4Si3晶体结构的全局优化及稳定性  

The global optimization and stability of Al4Si3 crystal structure

作　　者：陈宏善[1] 吴亚丽 张琳 张兆燕 赵俊淼 CHEN Hong-shan;WU Ya-li;ZHANG Lin;ZHANG Zhao-yan;ZHAO Jun-miao(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China)

机构地区：[1]西北师范大学物理与电子工程学院

出　　处：《西北师范大学学报（自然科学版）》2019年第5期29-32,共4页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11664034)

摘　　要：铝硅合金具有质轻、耐磨等优点,是重要的发动机缸体材料.铝硅合金主要以共晶结构存在,对铝硅晶体结构的研究可以帮助我们了解其成键性质及微结构.采用进化算法结合密度泛函理论研究了Al4Si3晶体的全局最稳定结构,结果表明,P4/MMM结构的结合能最大,为-29.05eV.能带和电子局域函数表明Al4Si3晶体是零带隙导体,Si-Si、Al-Si键都是强共价键.对弹性模量和声子谱的分析也表明P4/MMM结构是动力学稳定的,还讨论了其力学性能.Aluminum-silicon alloy is an important engine block material with light weight and excellent wear resistance.Al-Si alloys exist mainly in eutectic structure.The investigations on the Al-Si crystal structures can help us understand the bonding properties and microstructures.This paper studies the global minima structure of Al 4Si 3 crystals by using evolutionary algorithm combined with the density functional theory.The results show that the P4/MMM structure has the largest binding energy of -29.05 eV.The electronic band structure and the electron localization function indicate that the Al 4Si 3 crystal is a zero band gap conductor,and the Si-Si,Al-Si bonds are strong covalent bonds.Analyses on the elastic modulus and phonon spectrum show that the P4/MMM structure is dynamically stable,and its mechanical properties are also discussed.

关 键 词：铝硅合金 P4/MMM结构 电子性质 弹性模量 声子谱 

分 类 号：O641.2[理学—物理化学]