Sintering of titanate based dielectrics doped with lithium fluoride and calcium borosilicate glass

The effect of LiF and CBS glass additives on the microstructure and dielectric property of BaTiO3 (BT) ceramics was studied. The phase of BaLiF3 was observed from the interaction between BT and LiF when the samples were sintered at 900 °C for 1 h. Crystal grains with Ba and F in atomic ratios of 1:3 were observed from the SEM and TEM analysis of the microstructures. Abnormal grain growth (AGG) was observed to occur in the BT ceramics sintered at 950 °C. Further improvement to the composition was achieved by employing a two-stage process. This included CBS glass shell coating of the BT particles in the first stage, and the addition of LiF in the second stage. The composition thus formed had very good permittivity (1725) and an extremely low dielectric loss value (0.008).