HIP Sintering of Fine Grained Barium Titanate

Pure fine-grained barium titanate powder with a particle size of 0.1μm was sintered by the HIP (Hot Isostatic Pressing) method using a platinum capsule. HIP is an effective process for sintering barium titanate for reducing the sintering temperature and grain size. The densification proceeded at the HIP temperature 800°C under the pressure of 500MPa. The HIP sintered fine-grained barium titanate exhibited a lower dielectric constant and broader temperature characteristics at the Curie point (Tc) than that for a normal-sintered sample. A close relationship was obtained between the dielectric constant and the HIP treatment temperature. With lowering the HIP treatment temperature or time, both the dielectric constant and the peak temperature of the dielectric constant decreased. The grain size of the samples ranged under 1μm, much smaller than that of the normal-sintered samples.