氢化锂中氢行为的第一性原理研究

First-principles calculations of the hydrogen migration in lithium hydride

采用基于密度泛函理论的第一性原理,对氢化锂中间隙氢离子的形成以及迁移行为进行了研究,结果表明间隙氢离子沿[1 1 1]方向迁移势垒最小,迁移到最近邻间隙和次近邻间隙时由其近邻氢离子主导的可能性更大,室温下间隙氢离子可自发迁移到最近邻间隙和第三近邻间隙.氢离子迁移到次近邻间隙和第四近邻间隙形成Frenkel缺陷的可能性最大,是形成Frenkel缺陷最可能的两个位置.

First-principles calculations on hydrogen ions＇formation and migration have been down in lithium hydride. It is found that the migration along [ 1 1 1 ] gives the lowest activation energy. Hydrogen ions which mi- grate to the nearest clearance and the second neighbor clearance are more likely leaded by its nearest hydrogen ion. At room temperature, hydrogen ions can spontaneously migrate to the nearest and the third neighbor clearances. For the formation of Frenkel defects, we find that the hydrogen ions most likely migrate to the second and the fourth neighbor clearances. These two positions are the best ones for the formation of Frenkel defects.