By combining the reactive template grain growth (RTGG) with the spark plasma sintering (SPS) process, a dense and highly textured Ca3Co4O9 was produced. The degree of orientation and the thermoelectric property were estimated with various template sizes. The degree of orientation in green tapes was improved by increasing of the particle size due to the particle's interaction and parallelization in the tape casting. The increased alignment also enhanced the texturing of the Ca3Co4O9 during the SPS process, therefore, the bulk density and electrical conductivity of Ca3Co4O9. The Ca3Co4O9 ceramics prepared by the RTGG and SPS process possess of the maximum power factor of 5.2 × 10-4 W/mK2 at 1273 οC.

Keywords: Spark plasma sintering, Reactive template grain growth, Particle size, Ca3Co4O9.