Thermoelastic heterogenity in a model metallic glass from molecular dynamics calculations

It is well known that the elastic properties of amorphous systems are heterogeneous, leading to peculiarities in vibrational spectra and thermal properties. In this work, we investigate the heterogeneity in thermoelastic properties, and more precisely in the thermal expansion coefficient, in a model metallic glass. We find heterogeneities that are similar - in terms of length scales - to those in elastic constants. It has been suggested that such heterogeneities could be the reason for "cryogenic rejuvenation" processes observed under thermal cycling in several experiments. We investigate this hypothesis by comparing the values of the local yield stresses with the stresses generated by heterogeneities in thermal dilation.