Effect of Li2O-SiO2-xMO glass addition on the dielectric properties and microstructures of (Ba,Ca)(Ti,Zr)O3 for multilayer ceramic capacitors with nickel electrodes

The effects of glass composition on the diffusion at grain boundaries and the dielectric properties of the (Ba,Ca)(Ti,Zr)O-3 (BCTZ) system were investigated. The BCTZ system added with 0.3 wt% Li2O-SiO2-xMO glass (MO : matrix element and MnO, Y2O3) was sintered at 1130 degreesC in the reducing atmosphere. Insulation resistance was sharply increased with MO contents, while dielectric constant was slightly increased with MO content. In the BCTZ specimen added with Li2O-SiO2 glass (x = 0.0), Ba and Ti ion deficient regions were observed near grain boundaries compared to the grain. However, in the BCTZ specimens added with Li2O-SiO2-xMO glass, homogeneous distributions of Ba and Ti ion were observed in the grain and grain boundaries. The increase of insulation resistance with MO content might be caused by the homogeneous distributions of Ba and Ti ion in both grain and grain boundaries.