Preparing nanometer scaled Tb-doped Y2O3 luminescent powders by the polyol method

Sub-micrometer Tb-doped Y2O3 luminescent powders were prepared from nitrate precursors using the polyol method. Just after precipitation, the powders consist of agglomerates with a spherical shape and a size ranging between 400 and 500 nm. Each agglomerate is composed of ultra-small crystallites (from 3 to 6 nm) of a bee oxide phase whose luminescence presents original features in comparison with bulk materials. Powders were further calcinated at different temperatures and for annealing below 900 degrees C, highly crystalline samples with the classical green D-5(4) -> F-7(5) luminescent transitions of Tb3+ ions are obtained. For optimized annealing temperatures, sintering between the agglomerates is avoided and a sub-micrometric powder with a narrow size distribution and a high luminescence is obtained. (c) 2004 Elsevier Inc. All rights reserved.