The effect of Tb3+ doping on the structure and spectroscopic properties of MgAl2O4 nanopowders

In this paper, a modified sol-gel method was employed to prepare nanostructured MgAl2O4 spinel powders doped with Tb3+ ions and thermally treated at 700 and 1000 degrees C for 3 h. The structural properties of the prepared at 700 and 1000 degrees C powders where characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). According to obtained XRD patterns the formation of single-phase spinels after calcination was confirmed. The XRD analyses demonstrated that the powders were single-phase spinet nanopowders with high crystallite dispersion. The Rietveld method was applied to calculate lattice parameters. The averaged spinel particle size was determined to be similar to 10 nm for calcination at 700 degrees C and similar to 20 nm at 1000 degrees C. The emission and excitation spectra measured at room and low temperature (77 K) for the samples calcined at 700 and 1000 degrees C demonstrated characteristic spectra of Tb3+ ions. The effect of MgAl2O4:Tb3+ grain sizes on luminescence properties was noticed. (C) 2011 Elsevier B.V. All rights reserved.