Diffusion of muonium and hydrogen in diamond.
Diffusion of muonium and hydrogen in diamond.
复制标题
锷和氢在金刚石中的扩散。
DOI：
10.1103/physrevlett.99.205504
复制
发表时间：
2007
影响因子：
8.6
通讯作者：
R. Ramírez
中科院分区：
文献类型：
--
作者：
C. Herrero;R. Ramírez
基于路径积分质心理论，用量子过渡态理论计算了金刚石中μ素和氢的跃迁率。这种技术使我们能够研究振动模式量子化对杂质扩散的有效自由能垒Δ F的影响，这些自由能垒相对于零温度经典计算被重正化。对于从四面体（T）位置到键心（BC）位置的跃迁，氢的Δ F大于μ 鎓的Δ F，而对于BC → T的跃迁则相反。计算出的有效势垒随温度的升高而降低，除了从T到BC位点的μ素跃迁。计算的跳跃率与现有的μ子自旋旋转数据吻合得很好。
Jump rates of muonium and hydrogen in diamond are calculated by quantum transition-state theory, based on the path-integral centroid formalism. This technique allows us to study the influence of vibrational mode quantization on the effective free-energy barriers DeltaF for impurity diffusion, which are renormalized with respect to the zero-temperature classical calculation. For the transition from a tetrahedral (T) site to a bond-center (BC) position, DeltaF is larger for hydrogen than for muonium, and the opposite happens for the transition BC-->T. The calculated effective barriers decrease for rising temperature, except for the muonium transition from T to BC sites. The calculated jump rates are in good agreement with available muon spin rotation data.