Microstructure and properties evaluation of TiO2 ceramics with multi-oxides glass additions

A unique glass composition based on GeO2, MoO3 and V2O5 (GMV) was designed to act as a sintering aid to enhance the densification and to adjust the dielectric constant of TiO2. This allows the low temperature co-fired ceramic processing (LTCC) of approximately 750 °C to be feasible with a desirable dielectric property. The effect of GMV glass concentration on the densification behavior and dielectrics properties of TiO2 was investigated by dilatometer, x-ray diffractometer, scanning electron microscopy and transmission electron microscopy. The addition of glass not only was found to accelerate the TiO2 phase transformation from anatase to rutile, but also to increase the densification rate and the grain size of TiO2. The glass additive formed a thin continuous liquid phase and rearranged TiO2 particles into a dense microstructure at much lower temperature. The dielectric constants of TiO2 were ranged from 28 to 45 depending on the concentration of glass additive, while the dielectric loss was decreased with the glass concentration as a result of denser TiO2 microstructure.