Promising high temperature thermoelectric properties of dense Ba2Co9O14 ceramics

Layered cobalt oxides have shown high thermoelectric properties. The n = 1 member of the Ban+1ConO3n+3(Co8O8) family, Ba2Co9O14, a new layered cobalt oxides family with Co(II) and Co(III) in the CdI2 layers, has been synthesized by solid state reaction and sintered as dense ceramics (relative density ∼ 93%) by Spark Plasma Sintering. It presents promising p-type thermoelectric properties at high temperature. The dimensionless figure of merit ZT is 0.032 at 660 K and 0.04 at 1000 K, which is about one quarter to one third of the ZT value of Ca3Co4O9 ceramics.