Synthesis and characterization of Gd2O3:Eu3+ phosphor nanoparticles by a sol-lyophilization technique

The characterization and luminescence properties of natiostructured Gd2O3:Eu3+ phosphors synthesized by a sol-lyophilization process are presented. After preparation of gadolinium-based sols from gadolinium nitrate and ammonium hydroxide, the so-prepared sols were freeze dried at -10degreesC and calcinated at different temperatures. For temperatures lower than 1300 K, highly crystalline samples with the cubic structure can be obtained without concomitant grain growth of the particles (<50nm). The luminescence spectra contain all possible transitions of Eu3+ with C-2 symmetry and present two major features: an increase of the luminescence efficiencies of the phosphors in comparison with that obtained by solid-state reaction and the presence of an additional peak at about 609 nm at the vicinity of the D-5(0) --> (7)F(0...)4 transition. (C) 2003 Elsevier Science (USA). All rights reserved.