Fabrication and dielectric properties of barium titanate-based glass ceramics for tunable microwave LTCC application

Low-fired ferroelectric glass ceramics were fabricated from glass powders with a basic composition of 0.65BaTiO3·0.27SiO2·0.08Al2O3. The combined addition of SnO2 (or ZrO2) and SrCO3 was conducted to modify the dielectric properties of the glass ceramics. The Sr-component could be incorporated preferentially in the perovskite structure after heating at 1000 °C. The bulk and thick film samples obtained by sintering glass powder with a starting composition of 0.65(Ba0.7Sr0.3)(Ti0.85Sn0.15)O3·0.27SiO2·0.08Al2O3 at 1000 °C for 24 h showed a broadened ɛr–T relation with Tc ≈ 10 °C and ɛr(max) ≈ 280 and microwave tunability of 32% at 3 GHz, respectively.