THE COMPOUND-FORMING BEHAVIOR IN LIQUID (TL1 2PB1/2)-TE AND (IN1/2PB1/2)-TE SYSTEMS/

The electrical conductivity, magnetic susceptibility and thermoelectri c power of liquid (Tl1/2Pb1/2)-Te and (In1/2Pb1/2)-Te systems have bee n measured as a function of composition in the temperature range from near the melting point to 1000 degrees C. The former system exhibits a conductivity minimum, diamagnetic maximum and change in the sign of t hermoelectric power in the vicinity of 42.8 at.%Te (corresponding to t he stoichiometric composition of Tl2Pb2Te3). On the other hand, simila r anomalies of electronic properties have been observed around 55.6 at .%Te (the stoichiometric composition of In2Pb2Te5) in the latter In sy stem. In addition, the temperature dependence of these electronic prop erties considerably differs in both systems, reflecting the bonding na ture of Tl-Te or In-Te pair. Energy band parameters around the Fermi l evel at the stoichiometric composition in both systems have been deter mined based on the model recently developed by Enderby and Barnes (Rep . Prog. Phys. 53 (1990) 85).