Co-precipitation synthesis and self-reduction of CaF2:Eu2+ nanoparticles using different surfactants

Europium doped Calcium fluoride (CaF 2 :Eu 2+ ) nanoparticles have been synthesized by co-precipitation method using different surfactants, in which anhydrous ethanol was used as solvent and the nanoparticles was sintered in air. The self-reduction was observed in the as-prepared CaF 2 :Eu 2+ nanoparticles and can be explained by charge compensation model based on the substitution. Scanning electron microscope (SEM) and X-ray power diffraction (XRD) showed that the nanoparticles were about 50   nm⿿1   μm and in a single phase. A broad emission centered at 425   nm due to Eu 2+ 4f 7 ⿿4f 6 5d 1 transition has been observed with excitation bands between 337 and 385   nm by the fluorescence spectrometer. The corresponding excitation spectra showed a wide excitation range in the violet region due to 4f 7 ( 8 S 7/2 )   ⿿   4f 6 5d 1 (t 2g ) The luminescent properties of the phosphor was thoroughly examined. Furthermore, the effect of using different surfactants on the sizes of CaF 2 :Eu 2+ nanoparticles, related mechanisms was also investigated.