High-temperature thermoelectric properties of Delafossite oxide CuRh1-xMgxO2

We report high temperature thermoelectric properties of doped delafossite oxide CuRh
_0.9
Mg
_0.1
O
₂
. The parent compound CuRhO2. is a band insulator and becomes metallic upon Mg doping for Rh. We found that polycrystalline CuRh
_0.9
Mg
_0.1
O
₂
shows a large thermoelectric power S ~ +270 μV/K despite its low resistivity ~ 6 mΩcm at high temperatures around 1000 K. Combining these with a thermal conductivity k ~ 80 mW/cm K, we estimate a large dimensionless figure of merit ZT ~ 0.15 at 1000 K.