Barium magnesium aluminate, BaMgAl10O17, was synthesized by a solid-state reaction between Al2O3 and sol-gel-derived BaM-F-4 precursors. The reaction temperature necessary for producing a single-phase material was reduced to 1300degreesC because of the higher reactivity and lower melting point of the fluoride precursors. Eu-doped BaMgF4 was also prepared and characterized to examine its suitability as a precursor for synthesizing BaMgAl10O17:EU2+ blue phosphors. It was demonstrated that Eu3+, which was used in the acetate form as a starting material, was reduced to EU2+ in the sol-gel processing of BaMgF4, as indicated by a broad blue emission due to an allowed d-f transition at 420 nm with an ultraviolet excitation at 290 nm. BaMgAl10O17:Eu2+, which showed efficient blue emissions at 450 nm with an ultraviolet excitation at 254 nm, was successfully prepared by heating a mixture of Al2O3 and Eu-doped BaMgF4 at 1300degreesC without any special reducing treatment. (C) 2004 The Electrochemical Society.