Low-temperature synthesis of fine BaMgAl10O17:Eu2+ phosphor based on the solubility isotherms

A homogeneous and stoichiometric BaMgAl10O17:Eu2+ (BAM) phosphor powder has been prepared by the citrate route. Solubility isotherms have been calculated for metal–citric acid–water system at 25 °C to predict the optimum pH condition, which was found to be pH=7 for preparing pure and stable metal citrate complexes. Well crystallized and sub-micrometer-sized BAM particles could be obtained by thermal decomposition of the optimally prepared citrate precursor at a temperature as low as 1150 °C. Though the luminescent properties of the present samples under UV excitation well reflect the bulk properties, VUV excitation has exhibited the luminescent properties greatly influenced by the surface, which might be due to the fine particle. The maximum luminance of the samples heat treated at 1350 °C was 105% in comparison with that of the commercial BAM under VUV excitation.