Luminescence properties of R₂MoO₆:Eu³⁺ (R = Gd, Y, La) phosphors prepared by Pechini sol-gel process

R₂MoO₆:Eu³⁺ (R = Gd, Y, La) phosphors were prepared by the Pechini sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), reflectance spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting phosphors. The results of XRD indicate that all of the R_1.96Eu_0.04MoO₆ (R = Gd, Y, La) phosphors crystallized completely at 800 °C. Y_1.96Eu_0.04MoO₆ and Gd_1.96Eu_0.04MoO₆ are of isomorphous monoclinic (α) structure, while La_1.96Eu_0.04MoO₆ preferentially adopts the tetragonal (γ) form. FE-SEM study reveals that the samples mainly consist of aggregated particles with an average grain size ranging from 100 to 250 nm. The luminescent properties of R₂MoO₆:Eu³⁺ (R = Gd, Y, La) phosphors are largely dependent on their structure, grain size, and powder morphology. The isomorphous Y₂MoO₆:Eu³⁺ and Gd₂MoO₆:Eu³⁺ phosphors show very similar luminescence properties, which differ greatly from that of the La₂MoO₆:Eu³⁺ phosphor.