Synthesis of Nano‐sized BaTiO ₃ Powders by the Rotary‐Hydrothermal Process

Abstract

Nano‐sized BaTiO 3 powders with narrow size distribution and high tetragonality were attempted to be synthesized by the rotary‐hydrothermal process in a water system as a novel technique, using a mixture of anatase‐type TiO 2 and Ba(OH) 2 as starting material. The rotary‐hydrothermal syntheses were performed under conditions with a rotary‐speed of 20 revolutions per minute at 423–523 K for 3–96 h. Highly‐ and mono‐dispersed BaTiO 3 powders mainly composed of coarse‐faceted particles with the tetragonal phase were successfully synthesized by controlling the conditions for rotary‐hydrothermal treatments. TEM and TG results revealed that these coarse‐faceted BaTiO 3 particles contained very few structural defects such as hydroxyl content. Thus, the rotary‐hydrothermal process was a useful method to synthesize very high‐quality BaTiO 3 particles, and the further control of various conditions of the rotary‐hydrothermal treatment is expected to control the crystalline phase and microstructures of final BaTiO 3 powders.