The optical properties of the BaMgAl10O17:Eu2+–Ba0.75Al11O17.25:Eu2+ solid solution were studied by using VUV excitation, emission and reflectance spectroscopy. Three unique Eu2+ emission centers were observed in a ratio that depended upon the composition of the host and the dopant concentration. Two of the emission centers were assigned to Eu on normal Beevers–Ross sites and Eu on anti Beevers–Ross sites. The defect chemistry of this system was modeled based upon the known behavior of the spinel (MgO·nAl2O3) system. Based on this model, the third Eu center could be assigned either to Eu near Al vacancies or to Eu associated with O atoms in the cation layer. In undoped materials exciton emission was observed, peaking at 263nm in BaMgAl10O17:Eu2+ and 285nm in Ba0.75Al11O17.25:Eu2+. This emission may be the mechanism of host-to-activator energy transfer in these phosphors.

Defect Chemistry and VUV Optical Properties of the BaMgAl10O17:Eu2+–Ba0.75Al11O17.25:Eu2+ Solid Solution. V.Pike, S.Patraw, A.L.Diaz, B.G.DeBoer: Journal of Solid State Chemistry, 2003, 173[2], 359-66