An alternative approach to predict Seebeck coefficients: Application to La3-xTe4

A thermodynamic understanding of Seebeck coefficient was demonstrated in terms of electrochemical potential. It divided the contributions to the Seebeck coefficient into two contributions: the effect of thermal electronic excitations due to Fermi distribution and the effect of charge carrier gradient due to thermal expansion. The procedure is illustrated within the rigid band approximation in terms of the electronic density-of-states and the quasiharmonic approximation in terms of the phonon density-of-states. Numerical results were given using the n-type high temperature thermoelectric material La3-xTe4 at x = 0.0.25, and 033 as the prototype at a variety of carrier concentrations. (C) 2019 Published by Elsevier Ltd on behalf of Acta Materialia Inc.