417 / 2019-02-28 22:15:26

The anomalies in molten tin

thermodynamics,phase transition

全体主题 > High Pressure Physics and Materials Science

Liquid is a common state of condensed matter. Compared with crystalline solids, the fundamental relationships between the structure and properties of liquids are far from being well understood. For instance, the structural origins of many liquid anomalies still remain unclear, but liquid-liquid phase transitions (LLPT) are believed to hold a key. Here, combining temperature-resolved X-ray diffraction, isothermal compressibility, specific heat and sound velocity measurements, we show unambiguous experimental evidence of a LLPT in molten tin. Meanwhile, the simple liquid quasiunversality is no longer valid at the whole power temperature range, and an abrupt change pronounced at the transition temperature. The temperature dependence of core-softening is a key to associate the special structure with the anomalous in thermodynamic and dynamic properties. Our findings provide an unparalleled physical picture on atomic packing in high temperature metallic liquid and also shed light on phase behavior in these related Sn-type metallic and alloy liquid.