The role of liquid-liquid transition in glass formation of CuZr alloys.

Some glass-forming liquids have different liquid phases that have the same composition but different structure, density and entropy. Based on experimental and molecular dynamics simulation, we here report thermodynamic, dynamic, and structural evidence of the liquid-liquid transition (LLT) in ten Cu-Zr glass-forming liquids well above the liquidus temperature. We find that for Cu-Zr alloys, the LLT is beneficial to glass formation, and there is a close relationship between the relative transition strength (RTS) of the LLT and the critical thickness representing the glass forming ability (GFA): the bigger the value of the RTS parameters, the stronger the GFA of Cu-Zr alloys. This work not only uncovers the role of the LLT of melts in the glass formation of solids, but also sheds light on the inheritance of properties of glassy solids from the aspect of the detectable dynamics of high-temperature melts.