Thermodynamic modeling of the Ga–Pt–Sb system

Abstract The Ga–Pt–Sb system was modeled using the CALPHAD (CALculation of PHAse Diagram) technique. Solution phases, liquid, fcc(Pt) and rhom(Sb), of the Ga–Pt–Sb ternary system were modeled with the substitutional solution model. The compounds, Ga 6 Pt, Ga 7 Pt 3 , Ga 2 Pt, Ga 3 Pt 2 , GaPt, Ga 3 Pt 5 , and GaPt 2 of the Ga–Pt system, and PtSb 2 , PtSb, Pt 3Prod. Type: FTP Sb 2 , and Pt 7 Sb of the Pt–Sb system, were treated as line compounds Pt m (Ga,Sb) n in the Ga–Pt–Sb system. The compounds Ga 3 Pt and Pt 5 Sb were treated as (Ga%,Pt,Sb) 3 (Ga,Pt%) and (Pt%,Sb) 5 (Ga,Pt,Sb%) in the Ga–Pt–Sb system on the basis of thermodynamic models of the respective binary system. A set of self-consistent thermodynamic parameters was obtained. Using these thermodynamic parameters, the experimental isothermal section phase relation at 773 K, the vertical sections at 25 at% Pt, the GaPt–GaSb, Ga 2 Pt–GaSb, Ga 7 Pt 3 –GaSb, and GaPt–PtSb 2 sections and the partial invariant reactions in the Ga–Pt–Sb system were well reproduced.