Reaction-temperature and quenching effects on the ultrafine particle size of pyrolyzed BaTiO₃

Abstract

Pyrolysis of Ba₂TiO₄ powder into ultrafine BaTiO₃ particles in CO₂ atmosphere had been performed under various reaction-temperature and quenching conditions. Analyzes of the crystallite size were made by TEM and X-ray powder diffraction methods. Above 650°C, the final particle size increases rapidly with the increasing temperature, and the quench-induced thermal stress has great effect in reducing the particle size, but below the temperature, all particles converge to a size of about 100Å. The reaction-temperature effect is interpretable in terms of the growth-controlled, or nucleation-sufficient reaction theory which also indicates the possible finest limit should reach to a particle size of about 95Å at temperature of about 130°C.