Single master curve for self-diffusion coefficients in distinctly different glass-forming liquids

Abstract

An existence of a single master curve for the long-time self-diffusion coefficients D(S)(L)(T) in diversely different glass-forming liquids is predicted over wide temperature T ranges above the glass transition point T(g) by analyzing various experimental and simulation data consistently from a unified point of view based on the mean-field theory recently developed. In order to scale those data appropriately, the power-law dependence of the α- and the β-relaxation times on D(S)(L) is used. Then, it is shown that any equilibrium data for self-diffusion of atom in different systems are all collapsed onto a singular function f(T(f)((α))/T) , where T(f)((α)) is a fictive singular temperature of atom α. Thus, we emphasize that any equilibrium self-diffusion data can be described by a single master curve f(x) above T(g)(>T(f)), while the data out of equilibrium start to deviate from f(x) around T(g).