Enthalpies of mixing for alloys liquid below room temperature determined by oxidative solution calorimetry

Fusible alloys, in particular gallium-based alloys liquid below room temperature (Ga-LMA), have applications in soft robotics, microelectronics, self-healing battery components, and 2D materials synthesis, making the study of their thermodynamic properties critical for the improvement and development of hybrid materials. To determine the enthalpies of formation/mixing of the eutectics for the binary Ga–In, the ternary Ga–In–Sn, and the quaternary Ga–In–Sn–Zn systems, a novel experimental calorimetric technique based on oxidative solution calorimetry was developed. The experimental results for the binary eutectic are consistent with previous data obtained by direct reaction and solution calorimetry, demonstrating the viability and precision of the experimental technique presented, which can now be extended to a large variety of liquid alloy systems at or below room temperature. To our knowledge, the heats of mixing in the ternary and quaternary systems represent the first reported experimental values. Both standard geometrical models and FactSage were used to calculate the enthalpies of mixing for these alloys, which agreed with the experimental data, providing a foundation to analyze the thermodynamics of other unknown Ga-based alloys.