有效介质理论计算He原子在金属钒中的扩散行为  

CALCULATION OF DIFFUSION BARRIERS FOR HELIUM ATOM IN VANADIUM BY EFFECTIVE MEDIUM THEORY

作　　者：吴仲成[1] 彭述明[1] 杨茂年[1] 龙兴贵[1] 刘琼[1] 

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621900

出　　处：《金属学报》2004年第1期36-39,共4页Acta Metallurgica Sinica

基　　金：国家自然科学基金50131050

摘　　要：采用有效介质理论,并考虑晶格驰豫的影响计算He原子在金属钒中的嵌入能,通过能量分析推测He原子在金属钒中可能的扩散路径和扩散势垒,计算结果表明,He原子在金属钒bcc结构的四面体间隙位置有能量的最低点,为4.37eV,在八面体间隙位置嵌入能比四面体间隙位置的稍大,He原子在金属钒的bcc结构中最有可能在(100)面内沿着由位置(1,1/4,1/2),(1,1/2,1/2),(1,3/4,1/2)联成的直线(或其等价晶面相应联线)向外扩散。The diffusion barriers for the single helium atom in vanadium are studied by effective medium theory, in which the structure relaxation caused by the embedded atom is considered. The most possible diffusion path and diffusion barrier are determined. A single helium atom has the minimum energy about 4.37 eV in the tetrahedral interstitial site of bcc vanadium, and the embedding energy in octahedral interstitial site is larger than that in tetrahedral interstitial site. Helium atom in the bcc vanadium crystal diffuses along the path linked with positions (1, 1/4, 1/2), (1, 1/2, 1/2) and (1, 3/4, 1/2) on the (1 0 0) plane or the equivalent paths on corresponding planes.

关 键 词：钒 He原子 有效介质理论 弛豫 嵌入能 扩散势垒 

分 类 号：TG111.6[金属学及工艺—物理冶金]