Luminescence spectroscopy of Eu3+ in Ca3Sc2Si3O12

Ca3Sc2Si3O12 doped with 1 mol% Eu3+ and having a cubic garnet structure was prepared by a solid state reaction. The low temperature luminescence spectrum shows no measurable D-5(0) -> F-7(0) band, in agreement with the location of the lanthanide dopant in a site of D-2 symmetry, i.e. with a Ca2+ substitution. On the other hand, the spectrum is clearly dominated by the D-5(0) -> F-7(4) band, which is significantly stronger than that for the other transitions originating from the D-5(0) level. This unusual behavior is explained on the basis of a model describing the distortion of the EuO8 coordination polyhedron from a cubic geometry to the actual D-2 one. (C) 2011 Elsevier B.V. All rights reserved.