Chemical Physics Letters, Vol.461, No.4-6, 218-221, 2008
On the (6)A(1) <- T-4(1) luminescence of Fe3+ in disordered nanocrystalline LiGa5O8 prepared by a combustion reaction
A combustion reaction yields nanocrystalline LiGa5O8 in the inverse-spinel phase (Fd(3)m) in contrast to previous attempts by quenching microcrystalline powders from 1350 degrees C. This follows from XRD, IR and luminescence spectra of Fe3+ at 298, 78 and 2.5 K. The ordered phase is obtained by calcination at 900 degrees C of the combustion product. The Fe3+ luminescence is assigned to the (6)A(1)(S) <- T-4(1)(G) transition of ions in tetrahedral sites in both polymorphs; this is confirmed by the similar behaviour of the (4)A(2)(F) <- T-4(1)(P) luminescence of Co2+ upon the order-disorder transition. The variation of the luminescence spectra is explained in terms of inhomogeneity and the T-d -> C-3 symmetry reduction. (C) 2008 Elsevier B.V. All rights reserved.