Excess enthalpies of liquid Bi-Ge-Te alloys

The excess enthalpies of liquid alloys in the ternary system Bi-Ge-Te were determined at 1193 K in a heat flow calorimeter for five sections BiyGe1-y-Te with y = 0.2. 0.4, 0.5, 0.6 and 0.8. The enthalpy surface in the ternary system is characterized by a valley stretching from the exothermic minimum in the system Ge-Te to the exothermic mimimum in the system Bi-Te. The analytical description of the excess enthalpies in the limiting binaries was made with the Redlich-Kister formalism. For the description of the thermodynamic functions in the ternary system the equation of Bonnier was taken using additional ternary coefficients. The calculated curves obtained from the optimization are in good agreement with the experimental data.