Low temperature sintering and dielectric properties of LaAlO3-BaSnO3-based microwave dielectrics

LaAlO3-BaSnO3 ceramics as a new microwave dielectric material were investigated in terms of optimum synthesis conditions and thereby the relative density, microstructure, solid-solution state, and dielectric properties with the addition of various sintering aids at different sintering temperatures. The dielectric properties of 0.9LaAlO(3)-0.1BaSnO(3) (LA-0.1BS) were strongly influenced by relative density, microstructure, chemical ordering, and mixing rule of the dielectric constant. Densification of the LA-0.1BS ceramics was improved from 82.3 to 96.13% with an average grain size of around 1.9 mu m at reduced sintering temperature by 250 degrees C. The LA-0.1BS ceramics sintered with 3 mol% of Bi2O3-SiO2 (BS) showed dielectric constant (epsilon(r)) similar to 21.18 with associated dielectric loss (tan delta) similar to 0.00824 and Q x f similar to 1213.59 (10 GHz) which could be achieved at low sintering temperature of 1400-1450 degrees C.