Combustion synthesis and photoluminescence properties of LaAlO3 nanophosphors doped with Yb3+ ions

Ytterbium doped lanthanum aluminate (LaAlO3) nanophosphors have been prepared by a combustion process with glycine as a fuel. The structures of the powders were determined by X-ray diffraction (XRD), the morphology of the annealed materials was observed using scanning electron micro scopy(SEM), the average crystalline grain sizes have been determined by transmission electron microscopy (TEM) and photoluminescence properties using fluorescence spectroscopy. Pure LaAlO3 phase was obtained at 800 °C heated for 4h, with an average crystal size, as determined by TEM, of 60nm. Emission spectra and decay times of main luminescence transitions were measured at room temperature. A strong emission is reported at 986nm from the (2F5=2-2F7=2 ) transition, whose intensity depends on Yb concentration.