Low firing and microwave dielectric properties of BaTi4O9 with B2O3–ZnO–La2O3 glass addition

A high-Q low firing ceramics material was fabricated from a composite of 80 wt% of BaTi4O9 powder and 20 wt% of B2O3–ZnO–La2O3 glass flux. The sample sintered at 900 °C for 3 h had the maximum bulk density. B2O3–ZnO–La2O3 glass was found to act as the sintering aid. The material sintered at 900 °C for 3 h consists of BaTi4O9, LaBO3, an unidentified crystal phase and residual glass phase, and possesses excellent microwave dielectric properties: permittivity k ≈ 27, quality factor Q × f ≈ 20,000 GHz, temperature coefficient of resonant frequency τf ≈ 6.5 ppm/°C.