Atomistic interpretation of the dynamic response of glasses

Abstract

Using detailed information on the spectrum of shear transformation dynamics previously obtained from low-strain, quasi-static anelastic relaxation in a metallic glass, the corresponding response to a cyclic force is calculated, and prevailing analysis approaches are evaluated. It is shown that the time–temperature superposition principle does not resolve the distribution of activation energies for shear transformations. The distribution of shear transformation zone sizes explains the microscopic mechanisms of both slow (α) and fast (β) relaxations, and the fact that the former are irreversible. These results suggest the need to re-evaluate past interpretations of dynamic behavior of glasses.