Fabrication and microwave dielectric characterization of cordierite/BZBS (Bi2O3-ZnO-B2O3-SiO2) glass composites for LTCC applications

Abstract The present work aims to fabricate cordierite/BZBS glass (Bi2O3-ZnO-B2O3-SiO2) composites through one-step heat treatment. Cordierite was synthesized from a solid-state reaction of aluminum hydroxide, magnesium hydroxide, and silica gel. BZBS glass was obtained through the classic melt quenching technique. Milled cordierite powder was mixed with different volume fractions of glass powders and heat treated at 950 °C. Considering the densification behavior along with the microwave dielectric features, two composites (C70G30 and C60G40) were chosen for further examination. These composites were separately heat treated at different temperatures from 650 up to 900 °C, then characterized due to phase development, microstructural evolution, and microwave dielectric properties. Gahnite precipitated as the dominant crystalline phase in all composites sintered at 850 °C. Among studying composites, C60G40 (sintered at 850 °C) and C70G30 (sintered at 750 °C), respectively showed the highest quality factor of 39,323 and 35,128 GHz and the least dielectric loss.