Thermodynamic description of the Au-In-Ga ternary system based on the CALPHAD method

Abstract: There has recently been a considerable attention to the possible role of semiconductor nanowires for future device applications. To make this development feasible, precise control over the growth mechanism is required. In the Vapor-Liquid-Solid growth, the most common growth mechanism, gas phase precursors decompose in presence of catalytic particles and after supersaturating the particles, solid nanowires start to nucleate and grow from the seed particle. The knowledge on the equilibrium state of the seed particle is useful to understand the growth mechanism. In this work, we investigated the thermodynamic description of the AuIn-Ga ternary system by calculating its phase diagram. Using this phase diagram, the state of the gold particles in Au-seeded nanowires containing In and Ga can be explained. The phase diagram was investigated experimentally and computationally. The most common technique for calculating phase diagrams, the CALPHAD technique, was used for the calculations. The measurements on the system were performed using relevant thermal, crystallographic, structural and compositional analysis techniques. The most important results of the measurements were the identification of a new ternary phase, the ternary solubilities and the phase transition temperatures. These enabled us to optimize the calculated phase diagram and hence the thermodynamic description of the system.