SYNTHESIS OF LANTHANIDE OXYSULFIDES ACTIVATED BY EU3- A TOPOCHEMICAL REACTION( )

The oxysulfide compounds La2O2S:Eu and Y2O2S were obtained directly fr om thermodecomposition of the respective oxalate compounds under argon and sulfur vapor. the obtained compounds were analyzed by infrared sp ectroscopy, X ray diffraction and luminescence spectroscopy. The parti cle size distribution and crystalline habit of the compounds were obse rved by scanning electron microscopy. Although the particle size of th e oxysulfide was found to be 30% - 40% smaller than the precursor oxal ates, the initial morphology was completely maintained, which indicate s the occurrence of a topochemical reaction from oxalates to oxysulfid es.