Synthesis and surface modification of submicron BaTiO3 powders via a facile surfactant-assisted method

Abstract

Due to their unique properties, well-dispersed barium titanate (BaTiO3) ultrafine powders can be used in wide-ranging fields. In the present work, by using barium hydroxide octahydrate (Ba(OH)2·8H2O) and α titanic acid (H4TiO4) as raw materials, uniform submicron BaTiO3 powders with tetragonal structure and high degree of crystallinity were prepared via a solid-state reaction method at relatively low temperatures. Moreover, by simply using the stearic acid (St) as the modifier to modify the surface of the aggregated BaTiO3 powders, well-dispersed BaTiO3 particles could be obtained, which were then examined by complementary characterizations such as XRD, TEM, HRTEM, SEM, Raman, FT-IR, XPS and EDS. The results indicated that the tetragonal BaTiO3 particles with submicron-size, good uniformity, and high crystallinity could be prepared at 800 °C for 1 h. Moreover, the addition of St for surface modification proved to be an effective way to avoid the agglomeration of the BaTiO3 particles to get well-dispersed products, where 1 wt % of St was found to be the optimum concentration. The demonstrated surfactant-assisted surface modification method is expected to be applicable for other ultrafine powders to get well-dispersed particles.