Synthesis of low temperature firing scheelite-type BaWO4 microwave dielectric ceramics with high performances

Abstract

The synthesis of scheelite-structured BaWO 4 ceramics at low temperatures using a Li 2 O–B 2 O 3 –BaCO 3 –CuO (LBBC) glass frit is reported in this study. Composite ceramics with the chemical formula BaWO 4 - x LBBC ( x = 0.25, 0.5, 1, and 2 wt%) were synthesized via the standard solid-phase method. A compact BaWO 4 matrix containing glass crystallized when sintered at 850 °C for only 30 min. The BaWO 4 ceramic with 1 wt% LBBC glass exhibits optimum microwave dielectric performance with Q × f = 58,855 GHz, ε r = 8.33, and τ f = −61.43 ppm/°C. A results of XRD and SEM analyses, microwave properties and the liquid-phase sintering mechanism for the ceramics are presented. • The Q × f value remained excellent for 58855 GHz while the temperature decreased from 1100 °C to 850 °C. • The compound was still the pure BaWO 4 phase. • The shorter soaking time (30min) can effectively reduce the energy consumption.