Luminescence properties of Y3Al5O12:Eu3+-coated submicron SiO2 particles

Silica submicron spherical particles coated with an yttrium aluminum garnet (Y3Al5O12, YAG) layer doped with Eu3+ were prepared by the sol-gel method. The structure and morphology of samples determined by the X-ray powder diffraction measurements and transmission electron microscope images, respectively, indicated that well-crystallized garnet nanocrystallites were formed with successive coating cycles. Similar trends were deduced from the evolution of the luminescence spectra. The ratio of integrated intensities of the 5D0 → 7F2 and 5D0 → 7F1 transitions was used to analyze the structural variations in the surroundings of the Eu3+ ion. The effect of coating was analyzed by comparing the luminescence properties of the Y3Al5O12:Eu3+ nanocrystalline powders and composite Y3Al5O12:Eu3+/SiO2 materials.