Sintering behaviour and microwave dielectric properties of MgO-2B2O3-xwt%BaCu(B2O5)-ywt%H3BO3 ceramics
Haiquan Wang, Shixuan Li, Kangguo Wang, Xiuli Chen, Huanfu Zhou
Abstract
Abstract This study investigates the bulk density, sintering behaviour, and microwave dielectric properties of the MgO-2B 2 O 3 series ceramics synthesised by solid-state reaction. According to the X-ray diffraction and microstructural analyses, the as-prepared MgO-2B 2 O 3 ceramics possess a single-phase structure with a rod-like morphology. The effects of different quantities of H 3 BO 3 and BaCu(B 2 O 5 ) (BCB) on the bulk density, sintering behaviour, and microwave dielectric properties of the MgO-2B 2 O 3 ceramics were investigated. Accordingly, the optimal sintering temperature was obtained by adding 30 wt% H 3 BO 3 and 8 wt% BCB. We also reduced the sintering temperature to 825 °C. Furthermore, the addition of 40 wt% H 3 BO 3 and 4 wt% BCB increased the quality factor, permittivity, and temperature coefficient of resonance frequency of MgO-2B 2 O 3 to 44,306 GHz (at 15 GHz), 5.1, and −32 ppm/°C, respectively. These properties make MgO-2B 2 O 3 a viable low-temperature co-fired ceramic with broad applications in microwave dielectrics.