Microstructural and optical features of a Eu-monazite

摘要

The obtention of europium-phosphate nanoparticles by the precipitation method and its thermal evolution to become ceramics materials is presented. The monazite structure was obtained from the rabdophane phase after firing at 1000 deg C during several hours. The powder characteristics made easy the pressing and sintering processes and it was possible to obtain high density bodies (relative density > 97 percent) at only 1200 deg C. The fluorescence spectra and the lifetimes were investigated as a function of the heating temperature, as well, the microstructure and the residual glassy phase. It was found that higher sintering temperatures (>1500 deg C) resulted in lower fluorescence emission than lower temperatures (maximum at 1200 deg C) as consequence of the microstructure detrimental. The gamma irradiation up to the dose of 18 kGys did not produce any appreciable effect in the optical properties; however, the sintering temperature modified the optical absorption in the UV range.