The diffusion of single adatoms of Ag, Pd and Cu on the Cu(001) surface were investigated. By observing the mechanisms of self-diffusion and heterogeneous diffusion, the diffusion frequencies of three kinds of adatoms under different temperatures were counted and diffusion barriers and the pre-exponential factors of diffusion frequency were fitted. The results of diffusion barriers were compared with those from the static calculation. The results showed that: Under 800K, the dominant diffusion mechanism of adatom Ag, Pd and Cu was the simple hopping mechanism. The hopping frequency of adatom Ag was the biggest, and that of adatom Pd was the smallest. For homogeneous and heterogeneous adatom diffusion processes, the relationship between diffusion frequency and temperature obeys the Arrhenius formula. The diffusion barriers fitted from Arrhenius formula were relevant to the surface structure and the cohesive energy of adatom on the surface. The transition temperatures of diffusion from the jump-mechanism-dominant to the exchange-mechanism-dominant were about 825 and 937K for Pd and Cu adatoms, respectively.

Molecular Dynamics Simulation of Heterogeneous Adatom Diffusion on Cu(001) Surface. Meng, L.J., Li, R.W., Sun, J.D., Liu, S.J.: Acta Physica Sinica, 2009, 58[4], 2637-43