Biogenic Silicate Glass-Ceramics : Physical, Dielectric, and Electrical Properties

Biogenic silicate glass-ceramics were synthesized from the rice husk (RH) and eggshell powder (ESP) using the melt-quench method. The FWHM (0.37-0.39), crystallite size (0.351- 0.370 nm) increased and the bandgap decreased from 3.43 to 3.15 eV as the ESP concentration increased from 10 to 20 wt.%. The higher dielectric constant at lower frequency range is attributed to the accumulation of charge carriers at the grain boundaries. Beyond ≥350°C, the maximum dielectric loss was observed due to hopping of charge carriers between Ca2+ and Si4+. The impedance decreased from 8×106 to 2×102 with respect to the frequency (1×103 to 1×105 Hz). After the kink temperature (495 °C), the activation energy was observed to be increased from 0.73 to 0.74 for ESP=10wt.% and from 0.76 to 0.78 eV for ESP=20wt.%. The study of silicate glass-ceramics suggests major applications in the field of advance optics, infrared heating elements and energy storage devices