Low firing and microwave dielectric properties of BaT4O9 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-Zn0-La2O3 glass flux. The sample sintered at 900 degrees 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 degrees C for 3 h consists of BaTi4O9, LaBO3, an unidentified crystal phase and residual glass phase, and possesses excellent microwave dielectric properties: permittivity k approximate to 27, quality factor Q x f approximate to 20,000 GHz, temperature coefficient of resonant frequency tau(f) approximate to 6.5 ppm/degrees C. (C) 2006 Elsevier Ltd and Techna Group S.r.l. All rights reserved.