Eu3+ luminescence – A local structural probe in Li5La3M2O12 (M = Nb, Ta) with garnet structure

Abstract

Li5La2.95Eu0.05M2O12 (M= Nb, Ta) compositions with garnet structure were prepared by conventional solid state reaction technique and photoluminescence was studied. The photoluminescence disclose that the 5D0→7F2 electric dipole transition at 611 nm is predominant in both cases; a clear evidence that Eu3+ occupies a non-centrosymmetric site in these host lattices. These emission results are contrary to the reported luminescence in Y3Al5O12 (YAG). From the Eu3+ emission studies, it can be concluded that the next nearest neighbors (NNN) cations influence the Eu3+ luminescence in these garnet phases.