Atomistic simulation of the point defects in TaW ordered alloy

作者：Lin, Zhong-Liang; Zhang, Jian-Min^*; Zhang, Yan; Ji, Vincent

来源：Pramana - Journal of Physics, 2011, 76(1): 127-138.

DOI：10.1007/s12043-011-0005-7

• TaW alloy
• vacancy
• anti-site defect
• migration mechanism
• modified analytic embedded-atom method

Combining molecular dynamics (MD) simulation with modified analytic embedded-atom method (MAEAM), the formation, migration and activation energies of the point defects for six-kind migration mechanisms in B-2-type TaW alloy have been investigated. The results showed that the anti-site defects Ta-w and W-Ta were easier to form than Ta and W vacancies owing to their lower formation energies. Comparing the migration and activation energies needed for six-kind migration mechanisms of a Ta (or W) vacancy, we found that one nearest-neighbour jump (1NNJ) was the most favourable because of its lowest migration and activation energies, but it would lead to a disorder in the alloy. One next-nearest-neighbour jump (1NNNJ) and one third-nearest-neighbour jump (1TNNJ) could maintain the ordered property of the alloy but required higher migration and activation energies. So the 1NNNJ and 1TNNJ should be replaced by straight [100] six nearest-neighbor cyclic jumps (S[100]6NNCJ) (especially) or bent [100] six nearest-neighbour cyclic jumps (B[100]6NNCJ) and [110] six nearest-neighbor cyclic jumps ([110]6NNCJ), respectively.

• 出版日期2011-1
• 单位陕西师范大学