Preparation and Characterization of Lanthanum Oxide doped Barium Zirconate Titanate (BaZr0.1Ti0.9O3; BZT) Ferroelectric Glass Ceramics

Abstract

[(BaZr0.1Ti0.9O3]-[2SiO2-B2O3]-[K2O] based borosilicate glass with and without 0.1 mol % La2O3 was successfully developed by melt-quench method. XRD and FTIR spectra of the glass sample shows broad peaks ~24-35° (2? value) which is due to the formation of amorphous borosilicate phase and presence of stretching and deformation vibrations of B-O-Si linkage and Si–O–Si bridges, respectively. Differential scanning calorimetry (DSC) of glass samples reveals that addition of 0.1 mol % La2O3 elevates the onset of crystallization temperature from ~560°C to ~628°C. Controlled crystallization of the glasses at 800°C for 3h leads to the formation of fresonite (Ba2TiSi2O8) phase. SEM-EDS analysis of the un-doped glass-ceramic sample shows the formation of micron sized L-shaped and needle shaped crystals. However, addition of 0.1 mol % La2O3 modify the L-shaped crystal structure to blocky globular crystals. Dielectric measurements shows that addition of 0.1 mol % La2O3 increases the dielectric constant from ~45 to ~125.