用第一原理研究钛/硅对铝晶界电子结构的影响  

First-principles Study of Effects of Impurities Ti/Si on Al Grain Boundary

作　　者：邓胜华[1] 李平[2] 李红[1] 

机构地区：[1]北京航空航天大学物理学院,北京100191 [2]安徽建筑工业学院数理系,合肥230022

出　　处：《硅酸盐通报》2009年第B08期194-197,共4页Bulletin of the Chinese Ceramic Society

摘　　要：在局域密度泛函理论的基础上,采用第一性原理的平面波赝势方法,计算了纯铝晶界及掺杂钛和硅后的弛豫原子结构,分析和研究了钛、硅杂质偏析对铝晶界的影响。结果表明:杂质钛的偏析使晶界略有膨胀,晶界处的电子密度明显增加,硅的偏析使晶界收缩,晶界处电荷密度明显增加。但两种掺杂元素的偏析均形成了较强的具有共价-金属混合性质的化学键,局域的强化学键会抑制或削弱材料的位错形成和延展特性,从而按照"bond mobility model"机制阻止了应力作用下的原子重组。Based on the local density functional theory, the atomic and electronic structures of the Al sigma 9 tilt grain boundary with segregated impurity atoms have been calculated by a first-principles pseudopotential method, so the effects of segregated impurities on Al grain boundary can be studied, the segregated impurities are titanium and silicon. According to the computing results, Both of the two cases form the covalent-mentallie character mixing bonds between impurity atoms with the neighboring Al atoms, these bonds should prevent the rearrangement of atoms under stresses, so it can be classified into the bond mobility model.

关 键 词：Al晶界 掺杂 第一原理 

分 类 号：TB303[一般工业技术—材料科学与工程]