Sintering Characteristic, Structure, Microwave Dielectric Properties and Compatibility with Ag of Novel 3MgO-B2O3-xwt% Ba(CuB2)O5-ywt% H3BO3 Ceramics

Abstract

In this study, 3MgO-B2O3-xwt%BCB-ywt%H3BO3 (2 ≤ x ≤ 8, 0 ≤ y ≤ 20) ceramics were sintered at the optimum temperature to form Mg3B2O6 and MgO phases. The effects of H3BO3 and BCB on product characteristics, phase transition, microstructure, and microwave properties of 3Mg-B2O3 ceramics were investigated. The intensities of diffraction peaks of two phases varied with changing the x and y values. After sintering at 950 °C, the ceramics with x = 6 and y = 15 achieved excellent microwave properties with a εr of 6.72, Q × f of 83205 GHz, and τf of −65.05 ppm/℃. Besides, the ceramic with x = 8 and y = 5 sintered at 925 ℃ also achieved good microwave dielectric properties with a εr of 6.64, Q × f of 78173 GHz, and τf of −57.27 ppm/℃. The sintering temperatures of above both ceramics are well lower than the melting point of Ag, showing promising applications in low temperature cofired ceramic devices. In particular, these two ceramics can be used as potential candidate materials for microwave ceramics for 5G technology, provided that τf can be further optimized.