A molecular dynamics simulation of the effects of excess free volume on the diffusion in metallic glasses (original) (raw)

By molecular dynamics simulations, the diffuse behaviour of the atomic species in a metallic glass (NiZr 2) as a function of the excess free volume, introduced in the form of localized defects, has been studied. Diffusion of both atomic species increases as the excess free volume increases. Two different behaviours have been detected: a transitory high-mobility regime, which follows the introduction of the excess free volume; and a low mobility regime, which starts acting as the introduced excess free volume spreads over the entire system. In the high mobility regime, a description of the behaviour of atomic-level properties such as local pressure, shear stress and the free volume density around diffusing atoms is attempted.