Structural and thermoelectric properties of n -type Sr 1− x Ti x MnO 3− δ perovskite system

A series of Sr 1− x Ti x MnO 3− δ (0.05 ≤ x ≤ 0.3) was fabricated by the solid-state reaction method. We studied the structural and thermoelectric properties of Sr 1− x Ti x MnO 3− δ , with respect to the partial substitution of Ti 4+ for Sr 2+ . The sintered Sr 1− x Ti x MnO 3− δ crystallized in the hexagonal perovskite-type structure with a space group of P6 3 / mmc . For x ≤ 0.1, the partial substitution of Ti 4+ for Sr 2+ led to increases in the electrical conductivity and the absolute value of the Seebeck coefficient, thus enhancing the power factor. The highest power factor (2.5 × 10 −5 Wm −1 K −2 ) was obtained for Sr 0.9 Ti 0.1 MnO 3− δ at 800°C. The partial substitution of Ti 4+ for Sr 2+ in SrMnO 3− δ led to a significant improvement in the thermoelectric properties.