Preparation and Dielectric Measurements of Niobium Pentaoxide Doped Barium Strontium Titanate Glass and Glass Ceramics

摘要

(Ba0.2Sr0.8)TiO3-B2O3-K2O based glass as well as glass ceramic with and without 0.1 mol % Nb2O5 were developed by the conventional melt quench method. XRD and FTIR spectra of the glass samples confirms the formation of amorphous structure and presence of stretching and deformation vibrations of B-O-Si linkage and Si-O-Si bridges, respectively. Differential scanning calorimetry (DSC) of the glass sample reveals that addition of 0.1 mol % Nb2O5 elevates the onset of crystallization temperature from ~600°C to ~675°C. XRD reveals that desired SrBaTiO3 phase was formed upon controlled crystallization of the glass samples at ~750-780°C for 3h. SEM-EDS analysis of the un-doped glass ceramic sample shows the formation of micron sized flower-like, and needle shaped crystals. However addition of 0.1 mol % Nb2O5 modifies the microstructure to irregular shaped crystals. Results from the dielectric measurements suggest that upon addition of 0.1 mol % Nb2O5 the dielectric constant remains the same as compared to the un-doped sample