Evidence for Liquid-Liquid Crossover in Ga-In Alloys

Ga-In alloys are characterized by low melting points, which makes them promising candidates for liquid metal applications. Recently, a possible liquid crossover at the eutectic composition, manifested in the liquid structure, has been suggested. Here we explore the existence of the proposed crossover by differential thermal analysis, sound velocity, and electrical resistivity measurements. All of these methods indicate the existence of a crossover in the liquid phase. Furthermore, the compositional range of Ga-In liquid alloys investigated has been extended to the eutectic point, increasing further the confidence in the characterization of the transition. Very good agreement in the transition temperature was found between the different methods, which enabled us to form a map of the liquid-liquid crossover region on the Ga-In phase diagram. We also identified anomalous behavior in the thermodynamic quantities of excess volume and compressibility, strengthening these observations of a liquid-liquid crossover. Thus, the present work confirms and validates the change in the liquid properties near the eutectic composition and provides novel evidence for the existence of a crossover in the near eutectic compositions in this technologically important system.