Structural characteristics and microwave dielectric performances of ZnZrNb2-xVx/2O8-1.25x-based ceramics for LTCC applications

Abstract

The ZnZrNb2-xVx/2O8-1.25x-based (0.2 ≤ x ≤ 0.6) ceramics with monoclinic wolframite structure were prepared by the solid-phase method at low temperature. The microscopic morphology, phase structure, low-temperature sintering mechanism, and microwave dielectric performances of ZnZrNb2-xVx/2O8-1.25x-based (0.2 ≤ x ≤ 0.6) ceramics were thoroughly analyzed. Low-temperature sintering densification of microwave dielectric ceramics was made achievable by substituting non-dense vanadium at the Nb location. The sintering temperature of ZnZrNb2-xVx/2O8-1.25x (x = 0.4) ceramics was reduced by 340 °C when compared to pure ZnZrNb2O8 ceramics due to the mechanism of liquid phase aided sintering. The self-generated low melting point phase forms a liquid phase during the sintering process reducing the sintering temperature. It is noteworthy that when sintered at 900 °C, the ZnZrNb2-xVx/2O8-1.25x (x = 0.4) ceramic exhibits extremely exceptional microwave dielectric performances: εr = 25.15, Q×f = 17,600 GHz (at 8.01 GHz), and τf = −53.25 ppm/°C. The proposed material configuration provides a candidate material with extremely broad application potential for LTCC applications and a practical and effective strategy for low-temperature sintering of Nb-based monoclinic wolframite structured microwave dielectric ceramics.