Roughening Transition of an Amorphous Metal Surface: A Molecular Dynamics Study

By molecular dynamics with an embedded atom potential we study the surface properties of amorphous Pd80Si20. We analyze the evolution of structural and dynamical properties on cooling across the glass temperature Tg and we observe that the surface undergoes a deroughening transition 100 K below Tg, coincident with an anomaly in the surface diffusion. We show that the transition does not depend on the details of the interatomic potential, and appears to be a general consequence of the surface kinetics close to Tg.