Abstract

The thermal analysis of B₂O₃-Bi₂O₃-SiO₂-ZnO (BBSZ) glass with different particle sizes and LiF addition was researched to study its temperature behavior. Next the composites with 50 wt% BaTiO₃–50 wt% BBSZ glass were prepared for shrinkage, microstructures and dielectric properties investigations. The differently treated BBSZ glass showed that the smaller glass particles clearly decreased its softening and crystallization temperatures. LiF addition had the same but much weaker effect.

The composites showed two-stage shrinkage related to the softening of the glass and new phase generation of Bi₂₄Si₂O₄₀ at 385–450 °C, and Bi₄BaTi₄O₁₅ over 680 °C. The microstructures of the composites sintered at 720 °C showed Bi₄BaTi₄O₁₅, BaTiO₃ and Bi₂₄Si₂O₄₀ with residual ZnO phase. LiF addition increased the amount of Bi₄BaTi₄O₁₅, thus increasing the loss value. However the particle size of the glass did not effect to the dielectric properties of the composites showing permittivity of 248–256 and loss of 0.013 at 100 kHz.