Self-diffusion along twist grain boundaries in Cu
Self-diffusion along twist grain boundaries in Cu
复制标题
Cu 中沿扭曲晶界的自扩散
DOI：
10.1557/jmr.1992.3202
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发表时间：
1992
影响因子：
2.7
通讯作者：
J. B. Adams
中科院分区：
文献类型：
--
作者：
M. Nomura;J. B. Adams
在以前的论文中，我们研究了空位扩散在两个大角度扭曲晶界在铜，使用EAM。在本文中，我们讨论了空位沿着沿着四个额外的扭转晶界（8.8 - 43.6 °）的扩散。计算了所有可能位置的空位形成能（0.14 - 1.42 eV），发现与相邻晶面的重合程度直接相关。最佳的迁移路径被发现与包括边界的螺旋位错相一致。空位迁移能被认为是低的（0.02 - 0.52 eV）。在边界处的自扩散的激活能被发现是小于体积值的一半，在一般协议与实验。计算的扩散速率，δ D，中高角度扭曲晶界与多晶材料的实验数据是合理的协议。扩散率被发现随着扭转角的增加而降低，与两组相互矛盾的实验数据相反。
In a previous paper we studied vacancy diffusion in two high-angle twist grain boundaries in Cu, using the EAM. In this paper, we discuss vacancy diffusion along four additional twist grain boundaries, from 8.8–43.6°. Vacancy formation energies in all the possible sites were calculated (0.14–1.42 eV) and found to be directly related to the degree of coincidence with the neighboring crystal planes. The optimal migration paths were found to coincide with the screw dislocations which comprise the boundary. Vacancy migration energies were found to be low (0.02–0.52 eV). The activation energies for self-diffusion at the boundaries were found to be less than half of the bulk value, in general agreement with experiment. Calculated diffusion rates, δD , for medium-high angle twist grain boundaries were in reasonable agreement with experimental data for polycrystalline material. Diffusion rates were found to decrease with increasing twist angle, in contrast with two sets of conflicting experimental data.