Preparation and Properties of ZrO2-Coated BaTiO3 Composite Particles by Sol-Gel Method with Zr-Alkoxide
Takashi HAYASHI, Akihiro TANIMURA, Hiroshi SHINOZAKI, Kazuya TAKANASHI, Hideyuki AOKI and Kyoichi SASAKI
Abstract:Chemical processing of ZrO2-coated BaTiO3 composites was investigated with the surface modification through the hydrolysis of zirconium alkoxide on the surfaces of BaTiO3particles. It was clarified from the BET measurement and the SEM observation that original BaTiO3 particles were homogeneously coated with zirconium hydroxide fine particles. 2mass%ZrO2-coated BaTiO3 (BT-05) bodies sintered at 1275 exhibited a flattened dielectric temperature dependence (dielectric constants of 3600 to 4700) with lower loss (tanΒof 5% in the temperature range of |30 to 110), indicating a relaxor characteristics. The microstructure of ZrO2-added BaTiO3 (BT-05) sintered bodies consisted of grains of several 0.9Κm which are much smaller than ones of non-added BaTiO3 sintered bodies, suggesting that the grain growth of BaTiO3 was suppressed by zirconia existing at the grain boundaries. Key Words:alkoxide method, coating, composite particles, dielectric constant