A mathematical study of the influences of dynamic parameters on the memory effect of glasses

Abstract

Retaining an imprint of their thermal history is a hallmark of glassy materials. Although its microscopic origin is still in debate, this memory effect is the potential to be utilized in engineering applications as a way to rejuvenate the glasses. For a better understanding of it, we investigated how the memory effect is affected by non-exponentiality and non-linearity, which are two basic features of glass dynamics. A mathematical model with a linear superposition of relaxation functions at a series of experienced temperatures was employed to reproduce the memory effect. The results demonstrate that non-exponentiality has a leading role in determining memory behaviors while non-linearity influences it weakly. An enhanced memory effect found in a recent multistep temperature training experiment is understood with the decreasing non-exponentiality caused by the increasing dynamical heterogeneities of the system. This work provides a guide to regulating the memory effect in practical applications.