The molten salt synthesis of (Y_1-xEu_x)₄Al₂O₉ solid solution powders and their pl properties

(Y_1-xEu_x)₄Al₂O₉ solid solution powders can be easily prepared by a simple and convenient method, which effectively combined a molten salt process with a chemical co-precipitation technique. All the samples were characterized by XRD, SEM, and photoluminescence (PL) spectra techniques. The results show that the incorporation of NaCl salt can greatly promote the formation and crystallization of (Y_1-xEu_x)₄Al₂O₉ crystallites, and lower their synthesizing temperature, and that their particle size and morphology strongly rely on x value, which finally dominates their PL properties. The prominent emission intensity of ⁵D₀→⁷F₂ transition rather than ⁵D₀→⁷F₁ indicates doped Eu³⁺ cations occupy Y³⁺ position in monoclinic Y₄Al₂O₉, which is sensitive to Eu³⁺ local environment, and at x = 0.10, there exist a maximum PL intensity due to the concentration quenching effect.