Influence of SiO2 Addition on the Dielectric Properties and Microstructure of (Ba0.96Ca0.04)(Ti0.85Zr0.15)O3 Ceramics

Abstract

In this study, the effect of SiO2 doping on the sintering behavior, microstructure, and dielectric properties of BaTiO3‐based ceramics was investigated. Silica was added to (Ba0.96Ca0.04)(Ti0.85Zr0.15)O3 (BCTZ) powder prepared using the solid‐state method. SiO2‐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 (BaTiSiO5) existed in samples when SiO2 was added in excess of 1%. The amount of the second phases was observed to increase as the number of SiO2 additives increased. It was found that BCTZ ceramics sintered with SiO2 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 SiO2 addition (3% and 5%) due to higher formation of BaTiSiO5. 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 BaTiSiO5 phase on the dielectric properties of BCTZ ceramics, the BaTiSiO5 composition was synthesized from individual BaCO3, TiO2, and SiO2 powders using conventional solid‐state methods. X‐ray diffraction results show the presence of mainly the crystalline phase, BaTiSiO5, in the sintered ceramics.