The L–G phase transition in binary Cu–Zr metallic liquids
The authors recently reported that undercooled liquid Ag and Ag–Cu alloys both exhibit a first order phase transition from the homogeneous liquid (L-phase) to a heterogeneous solid-like G-phase under isothermal evolution. Here, we report a similar L–G transition and heterogenous G-phase in simulations of liquid Cu–Zr bulk glass. The thermodynamic description and kinetic features (viscosity) of the L-G-phase transition in Cu–Zr simulations suggest it corresponds to experimentally reported liquid–liquid phase transitions in Vitreloy 1 (Vit1) and other Cu–Zr-bearing bulk glass forming alloys. The Cu–Zr G-phase has icosahedrally ordered cores versus fcc/hcp core structures in Ag and Ag–Cu with a notably smaller heterogeneity length scale Λ. We propose the L–G transition is a phenomenon in metallic liquids associated with the emergence of elastic rigidity. The heterogeneous core–shell nano-composite structure likely results from accommodating strain mismatch of stiff core regions by more compliant intervening liquid-like medium.
© 2022 the Owner Societies. Submitted 10 Sep 2021; Accepted 06 Dec 2021; First published 06 Dec 2021. W. L. J. and S. L. C. are supported by NSF grant with the award number DMR 1710744. K. S. is supported by the DFG, grant Sa337/10. The authors declare no competing financial interests.
Supplemental Material - d1cp04157f1.pdf