Effects of nano-LiTaO<SUB>3</SUB> crystallization on the dielectric and optical properties in Er<SUP>3+</SUP>-doped Li<SUB>2</SUB>O-Ta<SUB>2</SUB>O<SUB>5</SUB>-SiO<SUB>2</SUB>-Al<SUB>2</SUB>O<SUB>3</SUB> glasses

The precursor glass of LiTaO3 nanocrystals was prepared in a new Er3+-doped Li2O-Ta2O5-SiO2-Al2O3 system by the melt-quench technique. They were isothermally crystallized at 680°C for 3-100 h to obtain nanostructured glass-ceramics. The X-ray diffraction and transmission electron microscopy confirm the nanocrystallization of LiTaO3 (16-34 nm) yielding transparent glass-ceramics. A steep rise in the dielectric constant with the heat-treatment time is attributed to ferroelectric LiTaO3 crystallization. Photoluminescence spectra exhibit the 4l13/2&#8594; 4l15/2 emission transition of Er3+ ions at 1570 nm when excited at 984 nm. Its intensity and lifetime decrease with an increase in heat-treatment time due to concentration quenching effect