Authors: S. Jáuregui-Rosas, O. Perales-Pérez, M. Tomar, W. Jia, O. Vásquez, E. Fachini
Affilation: University of Puerto Rico- Mayaguez Campus, Puerto Rico
Pages: 990 - 993
Keywords: nanopartticles, Eu-doped G2O3, sol-gel, luminescence
Nanocrystalline Gd2-xEuxO3 phosphors by a simple sol-gel method have been synthesized. The effects of the annealing temperature and atomic fraction of Eu3+ ions (x) on the structural and luminescence properties of the mixed oxides have been investigated. X-ray diffraction analyses showed that pure and highly crystalline cubic-Gd2O3 host phase was obtained when the precursors, bearing different atomic fractions of Eu species, were annealed at different temperatures in air. The average crystallite size varied from 29nm up to 40nm when the annealing temperature varied from 750oC to 950oC, but no effect of Eu content was observed. Room-temperature photoluminescence spectra of Eu-Gd2O3 powders showed all possible transitions of Eu3+ species, being the 5D0 to 7F2 transition the most intense. On a comparative weight basis, the highest PL intensity was observed for ‘x’= 0.15 (7.5% w/w). The energy transfer from Gd2O3 host to Eu3+ dopant was clearly verified for all evaluated ‘x’ values. It was also found that the PL intensity was strongly dependent on both, the annealing temperature and the dopant concentration. It can be concluded that the luminescence quenching in Eu3+-doped Gd2O3 nanoparticles would results from exchange interactions.