Nanocomposite BaSO4/Y2O3:Eu powders prepared by heterogeneous nucleation processing

Forming core–shell-structured phosphor particles is an effect way to improve the properties of the rare-earth-doped inorganic luminescent systems, as well as to achieve a reduction in the amount of expensive rare earth metal. Heterogeneous nucleation processing is a commonly used method to prepared core–shell-structured particles. A nanocomposite BaSO₄/Y₂O₃:Eu³⁺ powder was prepared by coating BaSO₄ submicrospheres with nano-Y₂O₃:Eu³⁺ particles via heterogeneous nucleation processing. Thermogravimetric analysis and differential scanning calorimetry (TGA/DSC) were utilized to reveal the mechanism of the homogenous precipitation reaction process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) were utilized to characterize the BaSO₄/Y₂O₃:Eu³⁺ core–shell-structured phosphor particles. By controlling the hydrolysis of urea, BaSO₄ particles are well coated with the shell of Y₂O₃:Eu³⁺, and the nucleation of coating materials is predominantly heterogeneous rather than homogeneous. Photoluminescence spectra were utilized as well. The BaSO₄/Y₂O₃:Eu³⁺ particles show a red emission corresponding to ⁵D₀–⁷F₂ of Eu³⁺ under the excitation of ultraviolet.