Preparation of Nano-Barium Titanate by High Gravity Coprecipitation

For the problems of uneven particle size distribution and large particle size of industrially prepared BaTiO₃ powders, Sm³⁺ doped BaTiO₃ nanoparticles were prepared by impinging stream-rotating packed bed（IS-RPB） co-precipitation method. The effects of high gravity factor, initial velocity of impact and doping concentration on the particle size and particle size distribution of barium titanate were investigated. X-ray diffraction（XRD）, scanning electron microscope（SEM）, infrared spectrometer（FT-IR）, synchronous thermal analyzer（TG-DSC） and nano particle size analyzer were used to characterize the product morphology and particle size. The results show that the BaTiO₃ prepared by the impinging stream-rotating packed bed reactor has small particle size and uniform particle size distribution, and is tetragonal after high temperature calcination. The smallest particle size of 65 nm was obtained at an initial impact velocity of 21.24 m/s, a supergravity factor of 45, a doping concentration of 0.3%, calcination temperature of 950 ℃ and holding time of 2 h. And the density of the ceramics body was 6.4 g/cm~3 at sintering temperature of 1 150 ℃ and sintering time of 2 h, which is favorable to improve the dielectric properties of thin dielectric layers and ceramic stability. The preparation of barium titanate by high gravity co-precipitation method proposed in this paper is an industrially scalable preparation method.