Materials Research Bulletin, Vol.39, No.3, 343-355, 2004
Synthesis and crystal structures of Ba6Mg11F34 and the solid solutions (Ba6Mg11-xMxF34)-F-(II) (M-(II) = Mn, Fe) and luminescence of Ba6Mg11F34 : EU2+
Ba6Mg11F34, a new compound of the pseudobinary BaF2-MgF2 system, has been synthesized by solid state techniques from stoichiometric amounts of BaF2 and MgF2 and its crystal structure detennined by single crystal X-ray diffraction (space group P1, a = 7.5084(6), b = 9.9192(8), c = 10.0354(8) Angstrom, alpha = 81.563(2), beta = 72.402(2), gamma = 71.198(1)degrees, 3899 structure factors, 233 parameters, R(F-2 > 2sigma(F-2)) = 0.018, wR(F-2 all) = 0.046). It is isotypic with the copper(II) analogue, Ba6Cu11F34. The main features of the structure are a network of [MgF6] octahedra and three different [BaFx] polyhedra with x = 12, 11 + 1 and 13.Ba6Mg11-xFexF34 and Ba6Mg11-xMnxF34 solid solutions were prepared and their composition determined by single crystal structure analyses. The luminescence properties of Ba6Mg11F34 doped with Eu2+ were studied using fluorescence spectroscopy. The observed luminescence was pale blue with a maximum at 465 nm. (C) 2004 Elsevier Ltd. All rights reserved.