Doping concentration of Eu^3＋ as a fluorescence probe for phase transformation of zirconia

The Eu^3＋-Y^3＋ double-doped ZrO2 （8YSZ：Eu^3＋） phosphors with different doping concentrations of Eu^3＋ were synthesized by hydrothermal method. The dependences of the intensities of visible emission, decay lifetimes and crystal structures on Eu^3＋ doping concentration were investigated. The optimal doping concentration of Eu^3＋ in 8YSZ：Eu^3＋ nanophosphors was determined. The morphology and crystal structure of the resulting phosphors were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectra. The fluorescence properties of the resulting phosphors were investigated by photoluminescence spectra and decay curve. In this paper, 3 mol.% Eu^3＋ ions in 8YSZ：Eu^3＋ phosphors was the optimal doping concentration. When doping concentration was 3 tool.%, the nanophosphor had a pure tetragonal phase structure, the emission intensity was intense and decay lifetime was long, furthermore this system could be used to indicate the extent of phase transformation of thermal barrier coatings.