Y掺杂γ-TiAl电子结构的第一性原理计算  

First-principles Study on Electronic Structure of γ-TiAl Alloy Doped with Y

作　　者：夏金姣 梁文萍[1] 缪强[1] 任蓓蕾[1] 韩培德[2] 

机构地区：[1]南京航空航天大学,江苏南京210016 [2]太原理工大学,山西太原030024

出　　处：《稀有金属材料与工程》2017年第2期421-426,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51474131;51174119);江苏省普通高校研究生科研创新计划项目(KYLX15_0309);南京航空航天大学博士学位论文创新与创优基金(BCXJ14-11);江苏高校优势学科建设工程资助项目

摘　　要：采用基于密度泛函理论的第一性原理平面波赝势方法,计算过渡元素Y在γ-TiAl中占位情况,并优化了Ti_2Al_2、TiAl_2Y、Ti_3Al_4Y、Ti_7Al_8Y及Ti_(15)Al_(16)Y的结构模型,获得以上掺杂体系的几何结构、电子结构、形成能以及电荷布局值从而分析体系的稳定性、成键特性,预测掺杂体系的宏观性质。结果表明:Y元素优先占据Ti位;随Y掺杂浓度增加,晶格畸变逐渐增大,晶体形成能力逐渐变强,Ti(d)-Al(p)中共价性比例先增加后减小,其中Ti_(15)Al_(16)Y的共价性最弱,有利于γ-TiAl改善脆性。Site substitution of Y and the super-cell systems of γ-TiAl doped with Y were investigated by the first-principle plane-wave pseudopotential method based on density functional theory.The geometric and electronic structures,formation energy,Mulliken and bond population of Ti2Al2,TiAl2Y,Ti3Al4Y,Ti7Al8Y and Ti15Al16Y were obtained.The results show that Y prefers to be a substitute for Ti inγ-TiAl alloy.The addition of Y increases both lattice distortion of γ-TiAl and forming ability of the doped lattice.Moreover,the proportion of covalent properties increases first and then descends with increasing of Y doping content.Ti15Al16 Y has the weakest covalent properties,in favor of improving the brittleness of γ-TiAl.

关 键 词：金属间化合物 第一性原理 占位 电子结构 

分 类 号：TG146.23[一般工业技术—材料科学与工程]