Thermoelectric properties of oxygen deficient (K0.5Na0.5)NbO3 ceramics

• The Seebeck coefficient is high (−(600–700) µV/K).
• The thermal conductivity is stable between 3.5 and 4 W m−1 K−1 from 325 to 1000 K.
• Dimensionless figure of merit ZT at 1000 K is 0.012.

The white (K0.5Na0.5)NbO3 compound with a perovskite structure is largely studied as a lead free piezoelectric material. Pellets sintered by SPS present an oxygen deficiency and a lower resistivity. As other perovskite oxides such as SrTiO3 or CaMnO3 have already shown high thermoelectric properties, the thermoelectric properties of oxygen deficient (K0.5Na0.5)NbO3 dense ceramics sintered by SPS have been investigated and appears as very promising. Dimensionless figure of merit ZT at 1000 K is 0.012.