Evolution of ferroelectric LiNbO3 phase in a reactive glass matrix (LiBO2–Nb2O5)

Transparent glasses in the system (100 − x)LiBO2–xNb2O5 (5 ⩽ x ⩽ 25, in molar ratio) were fabricated by the conventional melt quenching technique. The as-quenched samples were amorphous as established via X-ray powder diffraction (XRD) studies. Differential thermal analyses (DTA) confirmed their glassy nature. The glass transition temperature (Tg) and the crystallization temperature were found to be strongly composition (x) dependent. Lithium niobate (LiNbO3) nanocrystals were produced within the glass by heat-treating it at 500 °C/3 h (for x = 15). Two-stage heat-treatment process has improved the optical transmission characteristics. Impedance analysis was done to rationalize the electrical behavior of these glasses embedded with 100 nm sized LiNbO3 crystallites. The observed pyroelectric response and ferroelectric (P vs E) hysteresis loop at room temperature confirmed the polar nature of these composites.