Dielectric properties of barium magnesiotitanate ceramics, $BaMg_6Ti_6O_1_9$

Phase-pure samples of barium magnesiotitanate, $BaMg_6Ti_6O_1_9$ (BMT) are prepared by the wet chemical 'gel-carbonate' method wherein the formation of BMT is complete below $950 ^oC$ as a result of the reaction between nanoparticles of $BaCO_3, MgO and TiO_2$. BMT powders are sintered at $1350-1450 ^oC$ to dense ceramics. Extensive melting is noticed when the bulk composition falls between $(0.4MgTiO_3+0.6BaTiO_3)$ and $(0.6MgTiO_3+0.4BaTiO_3)$ along the $MgTiO_3-BaTiO_3$ tie-line in $BaO-MgO-TiO_2$ phase diagram. Dielectric properties of sintered (BMT) ceramics have been investigated which showed \varepsilon \simeq 39 at 2 GHz, quality factor Q \geq10,000 and positive temperature coefficient of dielectric constant around 370 ppm $^oC^-^1$