Self-diffusion on Pd(1 1 1) by molecular dynamics simulation

We have studied the self-diffusion of single adatoms on Pd(1 1 1) surfaces using molecular-dynamics simulations along with a semi-empirical many-body interatomic potential for Pd, obtained within the second-moment approximation to the tight-binding model. The diffusion coefficient of Pd adatoms was computed, and was found to present Arrhenius behavior. The migration energy and pre-exponential factor were determined from the Arrhenius diagram and compared with recent scanning tunneling investigations of Pd/Pd(1 1 1) system. We conclude that our computed results are in better agreement with the experimental data, than those of previous computational works. The temperature dependence of the mean-square displacements and the relaxation of both surface atoms and adatoms in the normal to the surface direction were also obtained.