Sintering characteristics and microwave dielectric properties of Ba(Co1/3Nb2/3)O3–MnO2 ceramics

Abstract

Microwave dielectric ceramics with the composition of Ba(Co1/3Nb2/3)O3–MnO2 (BCN–MnO2) were prepared by the solid-state reaction method. The effects of MnO2 on phase composition, microstructure, sintering characteristics and microwave dielectric properties of BCN ceramics were investigated. The additive MnO2 slightly decreased the sintering temperature and improved the densification of BCN as sintering aids. The multivalent Mn was beneficial for maintaining the compositional stability of BCN, which broadened the region of the sintering temperature. The Q × f value and temperature coefficient of resonant frequency (τ f ) were improved by 0.3 wt% MnO2. BCN–0.3 wt% MnO2 ceramic sintered at 1,340 °C for 12 h in air exhibited good microwave dielectric properties with e r = 32.9, Q × f = 90,431 GHz, τ f = −12 ppm/°C.