Low-Temperature Sintering and Microwave Dielectric Properties of ZnNb2O6-TiO2 Ceramics with BaCu(B2O5) Additions

The influence of BaCu(B2O5) (BCB) on densification, phases, microstructure and microwave dielectric properties of ZnNb2O6-xTiO(2) (x=1.70-1.90) composite ceramics have been investigated. Undoped ZnNb2O6-1.8TiO(2) ceramics sintered at 1200 degrees C exhibit temperature coefficient of resonant frequency ((f)) similar to 9.25ppm/degrees C. When BaCu(B2O5) was added, the sintering temperature of the ZnNb2O6-1.8TiO(2) composite ceramics was effectively reduced to 950 degrees C. The results indicated that the permittivity and Qxf were dependent on the sintering temperature and the amounts of BaCu(B2O5). Addition of 3.0wt% BaCu(B2O5) in ZnNb2O6-1.8TiO(2) ceramics sintered at 950 degrees C showed excellent dielectric properties of epsilon(r)=40.9, Qxf=12,200GHz (f=5.015GHz) and (f)=+0.3ppm/degrees C.