Improvement of thermoelectric properties of lanthanum cobaltate by Sr and Mn co-substitution

Abstract We report thermoelectric (TE) properties of Sr and Mn co-substituted LaCoO 3 system from room temperature to 700  K . Sr-substitutions at La and Mn at Co site in LaCoO 3 improves the electrical conductivity ( σ ). Thermal conductivity ( κ ) of all the samples increases with the increase in temperature but decreases with the substitution in LaCoO 3 . An estimation of the electronic thermal conductivity ( κ e ) suggests a dominant phonon contribution to thermal conductivity in this system. A maximum value of the figure of merit is 0.14 at 480 K for La 0.95 Sr 0.05 Co 0.95 Mn 0.05 O 3 .