Structure and optical properties under VUV excitation of Mn2+ doped alkaline earth aluminate phosphors

Polycrystalline hexagonal alkaline earth aluminates M3Al16O27 with M,: BaMg2 Ba1.5Mg1.5 and Sr1.5Mg1.5 doped by divalent manganese and prepared by solid state reaction were investigated concerning their crystal structure and optical properties at room temperature. Rietveld procedures were used for structure parameters refinement. The investigated aluminate phosphors crystallize in the space group P6(3)/mmc. M2+ ions occupy both tetrahedral 4f lattice positions of the small cations in the unit cell. Transitions between the terms T-4(1) ((4)G) and (6)A(1) (S-6) within the 3d(5) configuration of the Mn2+ ion cause the green emission of the phosphors. It can be excited very efficient by VUV radiation. Spectral position of the emission band which seems to consist of two superimposed bands and its band width at half height as well as the shape of the excitation spectrum are almost independent of the composition of M-3 in M3Al16O27. The luminous flux of the investigated aluminate phosphors depends on their composition. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinbeim.