Substitution of Y3+ for Gd3+ on the luminescent properties of BaGd2O4:Eu3+ scintillating phosphors

•Energy transfer and competitive absorption between Gd3+ and Eu3+ ions may coexist.•The XEL intensity is enhanced by ten times as the full substitution of Y3+ for Gd3+.•The relative trap concentration can be modified by various substitution ratios.

The BaGd1.8−xYxEu0.2O4 (0 ⩽ x ⩽ 1.8) phosphors were synthesized by the conventional high temperature solid-state reaction (SSR) method at 1300 °C in air. The structure and optical performances of the as-synthesized phosphors were characterized using X-ray powder diffraction (XRD), excitation and emission spectra, X-ray excited luminescence (XEL) and thermoluminescence (TL) spectra. The XRD results reveal that the structure of the BaGd2O4 host are not alternated by the gradual substitution of Y3+ for Gd3+ ions. Both energy transfer and competitive absorption between Gd3+ and Eu3+ ions may coexist by the excitation and emission spectra. The XEL intensity increases with the elevated substitution ratios, i.e. the x values. The strongest XEL intensity increases by a factor of about 10 when compared with the x = 1.8 and x = 0.0 phosphors. The possible mechanism of enhancing Eu3+ emission was also discussed by the TL properties of BaGd1.8−xYxEu0.2O4 phosphors by the gradual substitution of Y3+ for Gd3+ ions.