Effect of crystallization on microwave dielectric properties of stoichiometric cordierite glasses containing B2O3 and P2O5

The effect of crystallization on microwave dielectric properties of cordierite glasses containing B2O3 and P2O5 additions was investigated. Two glasses containing 5 wt% B2O3/5 wt% P2O5 and 7.5 wt% B2O3/7.5 wt% P2O5 were studied. Both glasses were sintered to nearly full density at temperatures as low as 860 °C. The frequency constant and quality factor of α cordierite are, respectively, about five times and two times larger than those of glassy phase and μ cordierite. The temperature coefficients of resonant frequency are estimated to be about −13, −55, and −15 ppm/°C for glassy phase, μ cordierite, and α cordierite, respectively. As a result of the microwave dielectric properties of the individual phase, cordierite glasses containing α cordierite possess the best microwave properties.