High temperature thermoelectric performance of Ce doped Ca_3Co_4O_9

Thermoelectric materials Ca3Co4O9 doped with Ce in the composition of CexCa3-xCo4O9(x=0,0.1,0.3) were prepared by solid state reaction.The phase structures and microstructures of the oxides were investigated and the Seebeck coefficient,electrical conductivity and thermal conductivity were measured from room temperature to 973 K.It was found that the electrical resistivity and thermal conductivity decrease with an increase of temperature.While the Seebeck coefficient increases with an increase of temperature.The maximum figure of merit 0.23 is obtained for the Ce0.1Ca2.9Co4O9 at 973K.