Diffusion and jump-length distribution in liquid and amorphous Cu33Zr67

Using molecular-dynamics simulation, we calculate the distribution of atomic jumps in Cu33Zr67 in the liquid and glassy states. In both states the distribution of jump lengths can be described by a temperatureindependent exponential of the length and an effective activation energy plus a contribution of elastic displacements at short distances. Upon cooling the contribution of shorter jumps dominates. No indication of an enhanced probability to jump over a nearest-neighbor distance was found. We find a smooth transition from flow in the liquid to jumps in the glass. The correlation factor of the diffusion constant decreases with decreasing temperature, causing a drop of diffusion below the Arrhenius value, despite an apparent Arrhenius law for the jump probability.