Sintering Behavior and Dielectric Properties of Bi3NbO7Ceramics Prepared by Mixed Oxides and High-Energy Ball-Milling Methods

Abstract

The sintering behavior and dielectric properties of Bi3NbO7 ceramics prepared by the high-energy ball milling (HEM) method and conventional mixed oxides method with V2O5 addition were investigated. All the samples were sintered between 840° and 960°C. For the ceramics prepared by the mixed oxides method, the pure tetragonal Bi3NbO7 phase formed without any cubic phase. With changing sintering temperature, the dielectric constant ɛr lies between 79 and 92, while the Q×f values are between 300 and 640 GHz. The samples sintered at 870°C have the best microwave dielectric properties with ɛr=79, Q×f=640 GHz, and the temperature coefficients of resonant frequency τf between 0 and −20 ppm/°C. For the ceramics prepared by the HEM, a pure cubic phase was obtained. The ɛr changes between 78 and 80 and Q×f were between 200 and 290 GHz.