Effects of BaCu(B₂O₅) addition on sintering temperature and microwave dielectric properties of Ba₅Nb₄O₁₅–BaWO₄ceramics

Abstract

The effects of BaCu(B 2 O 5 ) (BCB) addition on the microstructure, phase formation, and microwave dielectric properties of Ba 5 Nb 4 O 15 -BaWO 4 ceramic are investigated. As a sintering aid, BaCu(B 2 O 5 ) ceramic could effectively lower the sintering temperature of Ba 5 Nb 4 O 15 -BaWO 4 ceramic from 1100 • C to 950 • C due to the liquid-phase effect. Meanwhile, BaCu(B 2 O 5 ) addition effectively improves the densification of Ba 5 Nb 4 O 15 -BaWO 4 ceramic and significantly influences the microwave dielectric properties. X-ray diffraction analysis reveals that Ba 5 Nb 4 O 15 and BaWO 4 coexist with no crystal phase of BaCu(B 2 O 5 ) in the sintered ceramics. The Ba 5 Nb 4 O 15 -BaWO 4 ceramics with 1.0 wt% BaCu(B 2 O 5 ) sintered at 950 • C for 2 h presents good microwave dielectric properties of ε r = 19.0, high Q × f of 33802 GHz and low τ f of 2.5 ppm/ • C.