Thermoelectric properties of filling controlled manganites

Abstract We have investigated the carrier-doping x dependence of Seebeck coefficient S ( T ) and resistivity ρ ( T ) in Nd 1− x Sr x MnO 3 (0.20⩽ x ⩽0.80) crystals. In the typical ferromagnetic region, S ( T ) is well explained by the Mott formula. The sign of S ( T C ) was found to change from negative to positive near the metal insulator phase boundary. In addition, we have discovered that the power factor, S 2 / ρ , is optimized at x =0.63 where the A -type antiferromagnetic metal and the C -type antiferromagnetic insulator coexist.