| Abstract Scope |
Ag-Cu-Se-Te is an important thermoelectric material system. Alloys were prepared with pure constituent elements, melted completely, and quenched. The solidified alloys were examined to determine their primary solidification phases and the boundaries of the miscibility gaps. Interestingly, all four of its constituent ternary systems, Ag-Cu-Se, Ag-Cu-Te, Ag-Se-Te, and Cu-Se-Te, exhibit miscibility gaps across large compositional ranges. There are even continuous liquid miscibility gaps extending through the entire ternary system in the Ag-Cu-Se and Ag-Cu-Te ternary systems. In the Ag-Cu-Se system, there are eight primary solidification phases, including a ternary compound AgCuSe. The boundaries of the liquid miscibility gaps are within the Ag and Cu₂Se primary solidification phase regime. When molten alloys solidify through these liquid miscibility gaps, liquid phases of different compositions are formed, resulting in unique microstructures. Various kinds of microstructures were observed in alloys solidified through miscibility gaps, which resulted from compositional differences, density differences, and surface tension. |