Comment on 'Disentangling interatomic repulsion and anharmonicity in the viscosity and fragility of glasses'

摘要

Krausserer et al. [Phys. Rev. B 95, 104203 (2017)] present an analysis of the fragility parameter derived from their model for the temperature dependence of the viscosity. The model equation for the isobaric fragility predicts a power-density scaling law under pressure because of its mathematical similarity to the equation resulting from the latter. Comparing both formulas we established the simple relationship between the lambda parameter X from Krausser, Samwer, and Zaccone (KSZ) and the density scaling exponent γ. Thus, one can easily determine the value of A. from y. However, using the reported value of the density scaling exponent for commonly known glass formers, we are not able to achieve a satisfactory description of the experimental data. Therefore KSZ are not consistent with the experimental power density scaling.