Microwave dielectric properties of low-temperature-fired MgNb2O6 ceramics for LTCC applications.

Abstract

MgNb2O6 ceramics doped with (Li2O–MgO–ZnO–B2O3–SiO2) glass were synthesized by the traditional solid phase reaction route. The effects of LMZBS addition on microwave dielectric properties, grain growth, phase composition and morphology of MgNb2O6 ceramics were studied. The SEM results show dense and homogeneous microstructure with grain size of 1.72 μm. Raman spectra and XRD patterns indicate the pure phase MgNb2O6 ceramic. The experimental results show that LMZBS glass can markedly decrease the sintering temperature from 1300 °C to 925 °C. Higher density and lower porosity make ceramics have better dielectric properties. The MgNb2O6 ceramic doped with 1 wt% LMZBS glass sintered at 925 °C for 5 h, possessed excellent dielectric properties: εr = 19.7, Q·f = 67 839 GHz, τf = −41.01 ppm °C−1. Moreover, the favorable chemical compatibility of the MgNb2O6 ceramic with silver electrodes makes it as promising material for low temperature co-fired ceramic (LTCC) applications.