Au-Sn金属间化合物的第一性原理研究  

First principles study of Au-Sn intermetallic compounds

作　　者：胡洁琼[1] 谢明[1] 张吉明[1] 刘满门[1] 杨有才[1] 陈永泰[1] 

机构地区：[1]昆明贵金属研究所,稀贵金属综合利用新技术国家重点实验室,昆明650106

出　　处：《物理学报》2013年第24期272-279,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:u0837601);云南省应用基础研究重点项目(批准号:2011FA026);云南省创新团队(批准号:2012HC027)资助的课题~~

摘　　要：采用基于密度泛函理论的第一性原理平面波赝势法,计算研究了Au-Sn二元系金属间化合物的生成焓、结合能、电子结构、弹性性质和结构稳定性.计算结果表明:Au5Sn合金的生成焓最小,说明Au5Sn较容易生成,但Au5Sn在热力学和力学上是不稳定的;AuSn2和AuSn4的键合作用较强,弹性模量、剪切模量均大于AuSn和Au5Sn;从电子结构的角度,AuSn2和AuSn4的成键主要来自于Au原子d轨道与Sn原子p轨道的杂化;而AuSn以Sn—Sn键的相互作用为主,Au5Sn相中Au的占比较大,导致Au—Au共价键发挥作用,抑制了Sn导带p电子的成键.A first-principles plane-wave pseudopotential method based on the density functional theory is used to investigate the energies, electronic structures, and elastic properties of intermetallic compounds of Au-Sn system. The enthalpies of formation, the cohesive en- ergies, and elastic constants of these compounds are estimated from the electronic structure calculations, and their structural stabilities are also analyzed. The results show that the Au5 Sn compound is unstable with respect to other compounds, and the bonding effects of AuSn2 and AuSn4 are stronger than those of AuSn and Au5 Sn, for there are the strong hybridizations between Au and Sn atoms in AuSn2 and AuSn4 compounds. The main bonding effect of AuSn is Sn—Sn bonding interaction, and due to the Au content being maximal in Au5 Sn the bonding of p electrons in Sn conduction band is suppressed by the covalent bonding of Au—Au.

关 键 词：电子结构 弹性性质 第一性原理 Au-Sn金属间化合物 

分 类 号：TG146.31[一般工业技术—材料科学与工程]