Preparation and thermoelectric properties of the rare earths doped Ca0.95RE0.05MnO3 (RE=Pr, Eu and Tb) oxide materials

Abstract

The rare earths doped Ca_0.95RE_0.05MnO₃ (RE=Pr, Eu, Tb) oxide bulk materials are fabricated and the effects of rare earths doping within low content on the thermoelectric transport properties of the CaMnO₃ oxide have been investigated. The results show that all doped oxide bulk materials are single phase with consolidated microstructure. The electrical resistivity is remarkably reduced on account of electron carrier density and mobility enhancement. The Seebeck coefficient is simultaneously reduced and the total thermal conductivity is decreased due to phonon thermal conduction confinement. The thermoelectric figure of merit ZT is improved with peak values of 0.12, 0.12 and 0.09 at 973 K for the Pr, Eu and Tb doped CaMnO₃ oxide materials, respectively, which are very much higher than that of the undoped oxide material.