New model of Gibbs free energy difference for bulk metallic glasses

A newly derived expression for estimation of Gibbs free energy difference (ΔG) between the crystalline and under-cooled liquid of glass-forming alloys have been utilized to obtain theoretical ΔG for a variety of alloy systems. It gives better results nearly overlapping with the experimental values over entire under-cooling region for all alloy systems studied in this paper. However, the theoretical results given by other expressions deviate from the experimental values even in small under-cooling region except that the expressions proposed by Thompson and Spaepen and Lad et al. give a close estimation to the experimental ΔG in the temperature region of 680-937 K for Zr41.2Ti13.8Ni10Cu12.5Be22.5 and 450-662 K for La55Cu10Ni10Al25, respectively. In addition, the results in present work will provide us with the evidence of the choice of the α values for different metallic glasses.