Abstract
Recent studies indicate that Ga doping further improves the ZT value of the CoSb3 phase. The Co-Sb-Ga ternary system is of high interests for thermoelectric applications. This study determines the Co-Sb-Ga liquidus projection which is fundamentally important for the understanding of phase transformation and materials microstructures. Ternary Co-Sb-Ga alloys are prepared, and their primary solidification phases are determined. The Co-Sb-Ga liquidus projection is constructed based on the experimental data of primary phases, and the phase diagrams of its three constituent binary systems, Co-Sb, Co-Ga, and Ga-Sb. The primary solidification phases are the three terminal solid solution phases, and six binary compounds, CoGa, CoGa3, GaSb, CoSb3, CoSb2, and CoSb. No ternary compound is found as the primary solidification phase. CoGa and CoSb primary solidification phases have the largest compositional regimes. The liquidus projection is also calculated using the Calphad method. The experimental determinations and the calculated results are in good agreement