Glass-forming ability correlated with the liquid-liquid transition in Pd_42.5Ni_42.5P₁₅alloy

Alloy melts can solidify into metallic glasses if cooled fast enough to avoid crystallization. Glass-forming ability (GFA), a measure of the ease of vitrification, is vital for the fundamental understanding of glass formation, and is also crucial for the application of metallic glasses. Previous studies of GFA mainly focused on the undercooled liquid phase, while the influence of the evolution of the stable melts on GFA is rarely addressed. Here we show that the Pd_42.5Ni_42.5P₁₅ glass-forming liquid, in which a first-order liquid-liquid transition (LLT) takes place at T_LL = 1063 K high above its liquidus temperature, shows significantly different GFA when quenched from the temperature above or below T_LL. Moreover, the pathway and kinetics of crystallization of the melt are strongly related to the kinetics of the LLT. Our work provides new insights into the vitrification process and the kinetics of crystallization, and contributes to designing more stable metallic glasses.