The instantaneous shear modulus in the shoving model

We point out that the instantaneous shear modulus G(infinity) of the shoving model for the non-Arrhenius temperature dependence of viscous liquids' relaxation time is the experimentally accessible high-frequency plateau modulus, not the idealized instantaneous affine shear modulus that cannot be measured. Data for a large selection of metallic glasses are compared to three different versions of the shoving model. The original shear-modulus based version shows a slight correlation to the Poisson ratio, which is eliminated by the energy-landscape formulation of the model in which the bulk modulus plays a minor role. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4724102]