Synthesis of dense lead titanate ceramics with submicrometer grains by spark plasma sintering

Dense PbTiO3 ceramics consisting of submicrometer-sized grains were prepare d using the spark-plasma-sintering (SPS) method. Hydrothermally prepared Pb TiO3 (0.1 mu m) was used as a starting powder. The powder was densified to greater than or similar to 98% of the theoretical X-ray density by the SPS process. The average grain size of the spark-plasma-sintered ceramics (SPS ceramics) was less than or similar to 1 mu m, even after sintering at 9000- 1100 degrees C, because of the short sintering period (1-3 min). The measur ed permittivity of the SPS ceramics showed almost no frequency dependence o ver the range 10(1)-10(6) Hz, mainly because pores were absent from the cer amics. The coercive field of the SPS ceramics was somewhat higher than that of conventionally sintered ceramics, which could be attributed to the smal l-grained microstructures of the SPS ceramics.