A link between mechanical heterogeneity and nontrivial local structural power-law response in a model metallic glass

The structural heterogeneity and mechanical inhomogeneity of metallic glasses at the nanoscale have been demonstrated by extensive experimental investigations, while their inherent correlation remains ambiguous. Based on elasticity theory, a model is developed to describe the local structural response of metallic glasses under hydrostatic deformation. We establish a linear relationship between the local bulk modulus and the nontrivial power-law exponent of the structural response and further verify this relationship by molecular dynamics simulations. The intrinsic link between the local structural response and elastic modulus reveals that the mechanical heterogeneity reflects not only the static atomic packing but also the dynamic evolution of the amorphous structure. Our findings provide direct evidence that mechanical heterogeneity is a feasible indicator for describing the structural heterogeneity of metallic glasses and shed some light on the non-cubic structural power law of disordered materials.