'Royal College of Obstetricians & Gynaecologists (RCOG)'
Abstract
The precursor glass of LiTaO(3) nanocrystals was prepared in a new Er(3+)-doped Li(2)O-Ta(2)O(5)-SiO(2)-Al(2)O(3) system by the melt-quench technique. They were isothermally crystallized at 680 degrees C for 3-100 h to obtain nanostructured glass-ceramics. The X-ray diffraction and transmission electron microscopy confirm the nanocrystallization of LiTaO(3) (16-34 nm) yielding transparent glass-ceramics. A steep rise in the dielectric constant with the heat-treatment time is attributed to ferroelectric LiTaO(3) crystallization. Photoluminescence spectra exhibit the (4)I(13/2) -> (4)I(15/2) emission transition of Er(3+) 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
