Thermoelectric power and activation energy for hopping conductivity in Pb0.78Sn0.22Te solid solutions with high In content

Using expressions based on the effective-medium method, we invoke hopping conductivity to explain the temperature dependence of thermoelectric power in the quaternary solid solutions (Pb0.78Sn0.22)(1-y)InyTe. Our estimates of the activation energy for hopping conductivity are in order-of-magnitude agreement with values obtained previously from analysis of the electrical conductivity in these materials using the results of percolation theory. We also discuss the conditions under which our expressions can be used. (C) 1996 American Institute of Physics.