Synthesis of Eu2O3 doped BaO-TiO2-GeO2 based glass-ceramics: Crystallization kinetics, optical and electrical properties

Eu3+ doped transparent glass-ceramics (GCs) containing non-centrosymmetric ferroelastic Ba2TiGe2O8 (BTG) crystals as the major crystalline phase have been synthesized. BTG crystal phase was generated in the glass matrix with mole percent composition 30BaO-15TiO(2)-55GeO(2) synthesized by melt quenching technique followed by controlled crystallization through ceramming heat-treatment. A diffusion controlled surface crystallization event with zero and constant nucleation rates was determined through a comparative study of some linear and nonlinear solid state reaction models. Nonlinear crystallization kinetics studies facilitated determination of the experimental ceramization temperature and time for fabrication of transparent glass-ceramics containing BTG nanocrystals. XRD, FTIR, TEM and FESEM measurements confirmed the dispersion of BTG nanocrystals of size 20-100 nm in the glass matrix. Local crystal environment around Eu3+ ions facilitated the enhancement of photoluminescence of glass-ceramics with respect to the precursor glass. High dielectric constant, low loss and dissipation factors were observed for the GCs.