Influence of SiO 2 Addition on the Dielectric Properties and Microstructure of (Ba 0.96 Ca 0.04 )(Ti 0.85 Zr 0.15 )O 3 Ceramics

In this study, the effect of SiO 2 doping on the sintering behavior, microstructure, and dielectric properties of BaTiO 3 ‐based ceramics was investigated. Silica was added to (Ba 0.96 Ca 0.04 )(Ti 0.85 Zr 0.15 )O 3 (BCTZ) powder prepared using the solid‐state method. SiO 2 ‐doped BCTZ ceramics with a high density and a uniform grain size were obtained and sintered at 1220°C in a reducing atmosphere. A second phase (BaTiSiO 5 ) existed in samples when SiO 2 was added in excess of 1%. The amount of the second phases was observed to increase as the number of SiO 2 additives increased. It was found that BCTZ ceramics sintered with SiO 2 are helpful in reducing the sintering temperature for a typical thick film and MLCC applications. However, there were disadvantageous effects on the dielectric properties with mere addition of SiO 2 addition (3% and 5%) due to higher formation of BaTiSiO 5 . Doping with a small amount of silica can improve the sintering and dielectric properties of BCTZ ceramics. In addition, to understand the effect of the BaTiSiO 5 phase on the dielectric properties of BCTZ ceramics, the BaTiSiO 5 composition was synthesized from individual BaCO 3 , TiO 2 , and SiO 2 powders using conventional solid‐state methods. X‐ray diffraction results show the presence of mainly the crystalline phase, BaTiSiO 5 , in the sintered ceramics.