The effect of Cu substitution on microstructure and thermoelectric properties of LaCoO3 ceramics
Abstract
La(Co, Cu)O3−δ ceramics were prepared by pressureless sintering of citrate precursor powders, and their thermoelectric properties were investigated with an emphasis on the influence of Cu doping and phase structure as well as microstructure. It was found that a secondary phase first appeared in the form of a network along the grain boundaries and then changed to dispersion with increasing Cu content, which effectively reduced the lattice thermal conductivity of the materials. The thermal conductivity was only 1.21 W m−1 K−1 for the sample LaCo0.75Cu0.25O3−δ, being much lower as for the thermoelectric