High-temperature thermoelectric properties of Delafossite oxide CuRh1-xMgxO2

We report high temperature thermoelectric properties of doped Delafossite oxide CuRh_1-xMg_xO₂. The parent compound CuRhO₂ is a band insulator and becomes metallic upon Mg doping for Rh. We found that polycrystalline CuRh_1-xMg_xO₂ shows a large thermoelectric power S ~ +270 muV/K despite its low resistivity ~6 mOmegacm at high temperatures around 1000 K. Combining these with a thermal conductivity kappa ~ 80 mW/cm K, we estimate a large dimensionless figure of merit ZT 7sim; 0.15 at 1000 K