Low temperature and microwave dielectric properties of TiO2/ZBS glass composites

TiO2-based ceramic/glass composites were prepared by non-reactive liquid phase sintering (NLPS) using zinc borosilicate (ZBS) glass with a deformation temperature of 588 C. The compounds Zn2SiO4 and Zn4B6O13 were formed after the sintering process, indicating that the ZBS glass was non-reactive in this system. For TiO2/50 vol% ZBS glass composites, a two-stage sintering behaviour was conducted as the sintering temperature increased. The former was related to the NLPS process and the latter appeared to be related to crystallisation. The dielectric constant (epsilonr) was mainly affected by the porosity and obeyed the logarithmic mixing rule. The quality factor (Qxf(0)) showed an increase and then a steep decrease after a maximum temperature of 850 C. TiO2/50 vol% ZBS glass composites sintered at 900 C had a dielectric constant (epsilonr) of 36, and a quality factor of 7500 GHz for application to LTCC filters.