High temperature thermoelectric properties of La1-xSr xFeO3 (0<x<1)

Thermoelectric properties of some oxide materials have been investigated for developing thermoelectric power generation devices which can be used at high temperatures in air. Most of them are n-type semiconductors. The perovskite-type oxides, La_1-xSr_x FeO₃ (0<X<1) are known as p-type semiconductors. We measured the thermal conductivity (λ) of these oxides as well as the Seebeck coefficient (S) and the electrical conductivity (ω) in a temperature range of 473-1273 K in air, and evaluated the figure of merit. The Seebeck coefficient was positive, and minimum value was measured around 700 K. The electrical conductivity increased with increasing temperature. The thermal conductivity slightly decreased with increasing temperature. The values of S, a and A of the sample with x=0.05 were 228 μ VK^-1, 21 S cm^-1 and 1.85 W m ^-1 K^-1, respectively, at 1273 K. The figure of merit was 0.59×10^-4 K^-1