Thermoelectric Ca3Co4O9 ceramics consolidated by Spark Plasma sintering

Hole-doped Ca3Co4O9 (Co349) ceramics were prepared using solid-state reaction. Two processing strategies have been used to produce the thermoelectric oxide ceramics, Conventional and Spark Plasma (SPS) Sintering to control the grains consolidation, texturation and sample densification. Thermoelectric properties were measured and the influence of the processing conditions on the properties was evidenced. SPS favours shorter elaboration times and produces samples with larger thermoelectric properties due to better densification and alignment. The effect of the free deformation and texturation using the SPS technique is discussed. Seebeck coefficient values of 180 mu V/K at 873 K are obtained.