Crystalline SnO2 Nanoparticles Size Probed by Eu3+ Luminescence

Size-controlled europium(III)-doped SnO2 nanoparticles dispersed inside of porous Vycor glass (PVG) were synthesized using the impregnation and decomposition cycle (IDC) method. XRD, DRS, and TEM analyses proved that the observed cumulative mass gain after each IDC is associated to a controlled growing of the SnO2 nanoparticles. Europium(III) emission spectra Were acquired for all samples and clear differences on the relative intensity of the D-5(0)-> F-7(2)/D-5(0)-> F-7(1) transitions were observed for different SnO2 nanoparticle sizes. The changes in the europium(III) emission spectra could be correlated with the increase of nanoparticle: sizes. The smaller superficial nanoparticle area decreases the amount of europium(III) at the surface, where it can be located in different environments over distorted symmetry sites, compared to the crystal lattice sites, where the ions probably are located, when the particles become bigger with no changes in their crystallinity degree. The linear plot between the asymmetric intensity ration of the D-5(0)-> F-7(2)/D-5(0)-> F-7(1) transitions and the particles area/volume ratio calculated from the XRD Scherrer data and particle size frequency counts (similar to 1/d) confirmed this behavior.