Transparent glass-ceramics containing LiTaO3 nanocrystals in
the aluminosilicate glass matrix were prepared and the formation
of LiTaO3 nanocrystals has been confirmed by XRD, FTIRR spectra,
FESEM and TEM images. The nanocrystallite size of LiTaO3 has been
evaluated from XRD and found to vary in the range 14–36 nm. This
evaluation correlates well with those obtained from TEM images.
The increase of dielectric constant in comparison to precursor glass
confirms the formation of high dielectric constant ferroelectric
LiTaO3 (εr = 52) in glassy matrix. The absorption spectra and NIR fluorescence
spectra of glass–ceramic nanocomposites demonstrate
that the Nd3+ ion has entered into the LiTaO3 crystalline phase
and form Nd3+:LiTaO3 nanocrystals. The decrease in NIR-excited
emission intensity and fluorescence lifetimes with progression of
heat-treatment time has been attributed to the clustering of Nd3+
ions which resulted in concentration quenching.