Atomic mobility in metallic glasses was studied by using molecular dynamics simulations. The dynamic behavior of the atoms was monitored by using 3 different complementary approaches. The first approach led to the identification of defects, in the disordered structure, via an analysis of the interatomic spacing. In the second approach, the movement of the atoms was directly monitored. This led to the observation of chain-like collective motions of groups of atoms. In the third approach, diffusive motion was introduced by amplifying a low-frequency localized phonon mode. All 3 of the approaches led to the conclusion that diffusion in metallic glasses was a strongly cooperative process which took place at specific sites in the structure.

Cooperative Atomic Motion in Metallic Glasses L.D.Van Ee, J.Sietsma, B.J.Thijsse: Philosophical Magazine B, 1997, 76[4], 519-27