A new process for lamellar texturing of thermoelectric Ca3Co4O9 oxides by spark plasma sintering

Processing of textured Ca3Co4O9 (Ca349) thermoelectric ceramics with a good platelet orientation by spark plasma sintering (SPS) consolidation is reported. Two configurations wherein: (i) the oxide powder, being directly introduced into the graphite mould and (ii) placing a compact pellet prepared from the oxide powder in the centre of the mould have been investigated. The free deformation configuration route is found to improve the microstructure and transport properties of Ca3Co4O9 TE oxides. The material prepared exhibited a better performance than the sample obtained by conventional SPS way.