Transformations in undercooled molten Pd_40.5Ni_40.5P₁₉

It was demonstrated that liquid phase separation by nucleation and growth (LNG) occurs in undercooled molten Pd_40.5Ni_40.5P₁₉ for undercoolings ΔT ≤ 60 K (ΔT = T_l − T where T_l is the liquidus and T is the kinetic crystallization temperature), and liquid state spinodal decomposition (LSD) occurs for ΔT ≥ 100. For 60 ≤ ΔT ≤ 100 K, it is the transition regime from LNG to LSD. A ternary phase diagram is introduced to summarize the reactions occurred in undercooled molten Pd_40.5Ni_40.5P₁₉. Finally, it is suggested that LSD has an important impact on glass-forming ability of metallic alloys.