Cathodoluminescence, SEM and EDX analysis of CaF2 and Tm2O3 pellets for radiation dosimetry applications

Abstract

Preparation and synthesis of luminescent materials has a special interest in medicine, industry and research due to the wide variety of applications offered by phosphors. In this study, pellets of a mixture of CaF2 and Tm2O3 which were pressed and thermally treated up to 600 °C were prepared in air. Combined SEM (scanning electron microscopy), EDX (energy dispersive X-ray analysis) and CL-RGB (cathodoluminescence red-green-blue) microanalysis and, complementarily spectral CL analysis of this phosphor were performed. EDX analysis showed that the activator was homogeneously distributed in the prepared specimens. The additional CL emission can be attributed to the properties of some luminescent centers that were apparently created during the annealing. In addition, it seems that other trapping centers were created by new structural defects during the preparation process in the CaF2 lattice. The combined techniques SEM/EDX/CL-RGB have confirmed their capabilities in the characterization of the prepared materials. This contribution provides a process and characterization methods used in the fabrication and characterization of a phosphor that can also be used to optimize the luminescent emission of other similar synthetic materials with rare earth oxides as activators.