The excess enthalpies of liquid In-Bi-Te and Sb-Bi-Te alloys

The excess enthalpies of liquid alloys in the ternary system In-Bi-Te were determined in a heat flow calorimeter for five sections InyBi1-yTe with y = 0.2, 0.4, 0.5, 0.6, and 0.8 at 1.73 K, for the section In0.5Bi0.5-Te at 1073 K and 973 K. Calorimetric measurements were also performed in the system Sb-Bi-Te for the section Sb0.5Bi0.5-Te at 1173, 1073 and 973 K. The excess enthalpies of the binary and ternary liquid alloys were adapted with the association model using the Lukas program. Ternary interactions were taken into account for the analytical description of both systems. The enthalpy surface of the systems is characterized by a trough of minima stretching from Bi2Te3 to In2Te3, or Sb2Te3, respectively The numerical values of the exothermic enthalpies decrease with increasing temperature by dissociation of associates. The decrease is small in the system In-Bi-Te and larger in the system Sb-Bi-Te.