Dilatometric shrinkage study on magnesium titanate-based ceramic systems

The development of dielectric materials for applications in the microwave frequencies has been increasing with rapid progress in mobile and satellite communication systems. Magnesium titanate (MgTiO₃)-based ceramics have been the favourite candidates for such applications due to their excellent dielectric characteristics, i.e. a moderate level of dielectric constant together with a high-quality factor and high-temperature stability. These outstanding performance, however, can only be achieved when the ceramics are highly dense. The work reported in this paper discussed the study on the dilatometric shrinkage behaviour of pure and zinc-doped magnesium titanate (Mg_1–xZn_xTiO₃ for x = 0–0.5) ceramic systems after the systems following the heating passage up to 1300 °C. The results were discussed based on the phase formation data recorded from powder X-ray diffraction (XRD). An additional 2 wt. % V₂O₅ to the MZT0.2 system has increased the shrinkage of the system, and hence the relative density. The V₂O₅ addition also prevented the grain growth and did not alter the structure. From 100 Hz to 20 MHz, the dielectric permittivity is constant; which varies from (15.4 – 17.0) ± 0.1 % throughout the samples, these values are therefore frequency independent. (paper)