On the reasons for low luminescence efficiency in combustion-made Lu2O3 : Tb

Nanocrystalline Tb-doped Lu2O3 was prepared via a combustion route. Its low luminescence efficiency could be dramatically increased through post-fabri cation heat-treatment. Infrared spectra showed that the main reason for suc h a behavior, typical of combustion-made phosphors, was the presence of OH- vibrations in the as-made material. The OH-groups responsible for these vib rations could be completely removed only by heating the materials to at lea st 1500 degreesC. A simple alteration of the synthesis procedure to assure evaporation of water before the combustion step led to a decrease in the OH -vibration intensities. mirrored by a noticeable increase in the emission e fficiency of the resultant powder. (C) 2001 Elsevier Science B.V. All right s reserved.