Anomalous pressure dependent phase diagram of liquid Ga–In alloys

Abstract Pressure dependent phase diagram of liquid Ga–In alloys was calculated using high accuracy measurements of sound velocity and density at ambient conditions. In particular, the eutectic temperature and composition were found to have anomalous dependence on pressure. These alloys belong to a new class of room-temperature liquid metals, which are considered for multiple novel applications. To establish a pressure dependent phase diagram, we have measured to high accuracy sound velocity and density measurements across a wide range of temperatures and compositions. The sound velocity and density of the Ga–In system in the liquid phase were measured by a modified pulse-echo technique and the constrained drop method respectively. Implementing a sub-regular solution model, the pressure dependence of the Ga–In phase diagram was calculated. The new phase diagram was corroborated by a novel experimental measurement of the eutectic temperature as a function of pressure, utilizing a Paris-Edinburgh high-pressure large volume cell. The eutectic composition and temperature are found to depend strongly on pressure, information which extends our understanding of the Ga–In system and its possible applications.