Thermodynamic and kinetic properties of amorphous and liquid states

The magnitude and temperature dependence of the liquid state shear modulus G, specific heat Cp, diffusivity D, and viscosity η should all be closely related, according to the interstitialcy model, if a recent proposal by Dyre et al. is generally true. They suppose that the viscosiety is given by η=η0 exp (F/kT), where η0 is a reference viscosity and F is given by the work required to shove aside neighboring particle in a diffusion process, where F=GVc and Vc is a characteristic volume. In the interstitialcy model the high frequency thermodynamic liquid state shear modulus is given by G(T)=G0 exp [−γ(T/T0−1)], where G0 is the shear modulus at a reference temperature T0, which can be taken as the glass temperature. The resulting non-Arrhenius behavior of the viscosity is compared with experimental data. A critical quantitative analysis for a Zr41.2Ti13.8Cu12.5 Ni10Be225 alloy does not support the shoving model, but the thermodynamic properties can be understood in terms of mixed interstitials composed of metal-beryllium complexes.