Preparation and Spectroscopy Characterization of Eu:MgAl₂O₄ Nanopowder Prepared by Modified Pechini Method

In the present work, a modified Pechini method was employed to prepare nanostructured MgAl₂O₄ spinel powders doped with Eu³⁺ ions. The XRD analyses demonstrated that the powders were single-phase spinel nanopowders with high crystallite dispersion. The average spinel particle size was determined to be ≈15 nm for calcination at 700 °C, and ≈20 at 1000 °C. The emission and excitation spectra measured for the samples calcinated at 700 and 1000 °C demonstrated characteristic spectra of Eu³⁺ ions as well as were measured the emission spectra of Eu²⁺ ions for the samples calcinated at 700 °C. The effect of MgAl₂O₄ grain sizes on luminescence properties was noticed. To explain these differences a detailed analysis of luminescence spectra by the Judd–Ofelt theory has been performed.