Mechanochemical Synthesis and Luminescent Properties of Pure and Dy-Doped SrMoO4 Crystalline Phases

The pure and xDy3+-doped SrMoO4 series (x = 0.5, 1.0, 1.5 and 2.0 at.%) were synthesized using a direct mechanochemical route. We found that a milling speed of 850 rpm and a milling time of 30 min result in a complete chemical reaction at different concentrations of dopant ions. The phase formation, structural units, and optical properties of the obtained samples were investigated by XRD, IR, UV-Vis and PL analyses. It has been established that Dy2O3 mainly influences the lattice parameters, unit cell volumes, crystallite sizes, and microstrains. The symmetry of MoO4 groups was investigated using IR spectroscopy, and it showed that pure and Dy3+-doped SrMoO4 samples are built up of deformed structural units. The calculated optical band gap of the obtained crystal phases decreases with increasing concentrations of Dy3+ ions. The host SrMoO4 matrix shows broad blue emission centered at 430 nm under an excitation wavelength of 230 nm. All doped samples display a strong yellow emission at 570 nm, belonging to the 4F9/2 → 6H13/2 transition of Dy3+ ions. The highest luminescence intensity was observed when the concentration of the Dy3+ ion was 0.5 at.%. The mechanism of concentration quenching was mainly caused by the electric dipole–dipole interaction. The calculated CIE chromaticity coordinates of the doped samples fall in the yellow range. This study demonstrates that mechanochemical treatment is an appropriate route for the fast preparation of yellow phosphors.