Effects of R_E-Cu Co-doping on Thermoelectric Properties of CaMnO₃

CaMnO₃ thermoelectric materials has been prepared by solid state reaction method, and effects of R_E-Cu co-doping on thermoelectric properties of CaMnO₃ are investigated in this paper. The results show that Pr-Cu co-doping and Ce-Cu co-doping don't change the crystal structure of CaMnO₃, and with the increase of Cu doping amount, the absolute value of Seebeck coefficient, resistivity, as well as the thermal conductivity of CaMnO₃ samples are all reduced firstly and then increased. What's more, the power factor and ZT value of the samples are properly enhanced by doping Cu. Consequently, better ZT value 0.088 is obtained at 973K in 0.01 Pr-0.05 Cu co-doped sample, and 0.08 in 0.05 Ce-0.02 Cu co-doped one.