Elastic properties associated with liquid–liquid phase transition in molten cerium

Cerium is regarded as one of the few metals that exhibit a first-order liquid–liquid phase transition (LLPT). However, despite the theoretical attribution of the LLPT to the localized-itinerant transition of f-electrons, there is still a lack of compelling experimental evidence to support this important scientific inquiry. In this study, we investigate the evolution of sound velocity in molten cerium along the isothermal and isobaric paths under static compression. Drawing parallels with the extensively studied γ–α isostructural phase transition, the V-shaped trend of temperature-dependent sound velocity in liquid suggests the existence of LLPT and identifies an associated mechanism predominating liquids' compressibility.