Abstract. We report the results of the comprehensive study of the structural, magnetic and optical properties of SrTiO3 perovskite doped with Eu3+ ions. Polycrystalline powders were obtained by sol-gel process including high-temperature annealing at 1300 °C. The structural analysis showed that material is composed of several phases with dominant SrТiO3 and considerable quantity of titanium dioxide (rutile, 10…20%). Both the amount of Eu and ratio of Eu:Sr in the final product are considerably smaller as compared to the original solutions for synthesis. The elemental analysis reveals europium only in the phase of EuSrTi2O7 compound for equimolar ratio of Eu and Sr during the synthesis. The EPR analysis reports deficiency of Eu2+ in the samples under investigations. SrTiO3:Eu3+ powders demonstrate weak photoluminescence, which intensity grows up with increasing the concentration of Eu and reaches its maximum at c.a. 8 mol.% of Eu in the original solutions. Addition of Al increases the intensity of photoluminescence (c.a. 2.2 for 10 mol.%). Emission spectra are typical for Eu3+ occupied sites with high symmetric environment (dominant 5D07F1 transition) with relatively low distortion (both 5D07F2 and 5D07F4 as well present, but with a lower intensity) of coordination polyhedron. Low solid-solubility limit of Eu3+ in perovskite matrix (less than 1 mol.%), peculiarities of optical spectra, effect of Al, production/annealing temperature dependence etc. have suggested that structural effects are dominating in functional, in particular, optical properties of SrTiO3:Eu3+ phosphors.

Keywords: sol-gel synthesis, photoluminescence, SrTiO3:Eu3+ phosphors.

Full Text (PDF)

References

Back to Volume 19 N4