Barium magnesium aluminate, BaMgAl 10 O 17 , was synthesized by a solid-state reaction between Al 2 O 3 and sol-gel-derived BaMgF 4 precursors. The reaction temperature necessary for producing a single-phase material was reduced to 1300°C because of the higher reactivity and lower melting point of the fluoride precursors. Eu-doped BaMgF 4 was also prepared and characterized to examine its suitability as a precursor for synthesizing BaMgAl 10 O 17 :Eu 2ϩ blue phosphors. It was demonstrated that Eu 3ϩ , which was used in the acetate form as a starting material, was reduced to Eu 2ϩ in the sol-gel processing of BaMgF 4 , as indicated by a broad blue emission due to an allowed d-f transition at 420 nm with an ultraviolet excitation at 290 nm. BaMgAl 10 O 17 :Eu 2ϩ , which showed efficient blue emissions at 450 nm with an ultraviolet excitation at 254 nm, was successfully prepared by heating a mixture of Al 2 O 3 and Eu-doped BaMgF 4 at 1300°C without any special reducing treatment.
2002 luminescence, fluorescence luminescence, fluorescence (solids and liquids) D 6540
-011Sol-Gel Processing of BaMgF 4 -Eu 2+ Thin Films and Their Violet Luminescence.-Thin films of the title compound are prepared by a sol-gel method from isopropanol solutions of Ba(OAc) 2 , Mg(OAc) 2 ·4H 2 O, Eu(OAc) 3 ·4H 2 O, CF 3 COOH, and H 2 O (20 • C, 2 h, followed by spin coating and heating at 500-700 • C for 10 min). The reduction of Eu 3+ to Eu 2+ in the heat-treated films is evidenced by the strong, broadband 4f-5d excitation at 290 nm and emission at 420 nm in photoluminescence measurements. The intensity of the violet luminescence of Eu 2+ depends on the heating temperature, heating time, and Eu concentration. The strongest violet emission is observed for the BaMgF 4 :Eu (15 mol%) thin film heated at 650 • C for 10 min.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.