Synthesis and Characterization of BaTiO_3 Fine Powders by Pulse jet Spray Pyrolysis

摘要

BaTiO_3 precursor powders were synthesized by two types of pulse jet spray pyrolysis-1000 and 2000 kcal/h types-using an aqueous solution of metal salt. All as-prepared powders crystallized to the cubic and other phases. However, the powders almost reached the tetragonal phase through calcination at 900 °C in air for 2 h. The crystallinity of the powders obtained from 2000 kcal/h type pyrolysis was higher than those obtained from the 1000 kcal/h type. When Ba(NO_3)_2 was used, nanoparticle formation at an average particle size of approximately 150 nm, with a narrow size distribution, was observed. The relative density of the sintered body was 87 %. The relative dielectric constant of the BaTiO_3 body was 1450, and its tan5 value was 0.017 at room temperature.