MANY-BODY NATURE OF THE MEYER-NELDEL COMPENSATION LAW FOR DIFFUSION

We present the results of a detailed embedded-atom-method molecular-dynamics study of diffusion on metallic surfaces with a view of establishing the validity of the compensation (Meyer-Neldel) law for phonon-activated Arrhenius processes. We find, indeed, that surfaces with large activation barriers for diffusion compensate by increasing their effective attempt-to-diffuse frequencies. The Meyer-Neldel energy we obtain agrees very well with bulk diffusion data. Our results confirm the role played by phonons in the activation, as well as the many-body nature of the excitations leading to diffusion and, therefore, to the Meyer-Neldel rule.