Abstract
The nanocrystalline Gd2O3:Eu3+ powders with cubic phase were prepared by a combustion method in the presence of urea and glycol.
The effects of the annealing temperature on the crystallization and luminescence properties were studied. The results of XRD show pure
phase can be obtained, the average crystallite size could be calculated as 7, 8, 15, and 23nm for the precursor and samples annealed at
600, 700 and 800 1C, respectively, which coincided with the results from TEM images. The emission intensity, host absorption and charge
transfer band intensity increased with increasing the temperature. The slightly broad emission peak at 610nm for smaller particles can be
observed. The ratio of host absorption to O2–Eu3+ charge transfer band of smaller nanoparticles is much stronger compared with that
for larger nanoparticles, furthermore, the luminescence lifetimes of nanoparticles increased with increasing particles size. The effects of
doping concentration of Eu3+ on luminescence lifetimes and intensities were also discussed. The samples exhibited a higher quenching
concentration of Eu3+, and luminescence lifetimes of nanoparticles are related to annealing temperature of samples and the doping
concentration of Eu3+ ions.
r 2006 Elsevier B.V. All rights reserved.
Keywords: Nanocrystalline Gd2O3:Eu3+; Combustion method; Emission; Luminescence lifetimes; Doping concentration of Eu3+