Electronic structure of Sm3+ ions in YAG and cubic sesquioxide ceramics

A comparative analysis of the low temperature energy level structure of Sm3+ ion in YAG and sesquioxide (Y2O3, Lu2O3, Sc2O3) microcrystalline ceramics, based on new and previously reported data is presented. The Stark level structure of Sm3+ ion is discussed in terms of nephelauxetic and crystal field effects, determined by structural characteristics of the centers (of D-2 symmetry for YAG and C-2 or C-3i for sesquioxides). The Sm3+ electronic structure of C-2 centers in sesquioxides presents some peculiarities (barycenters positions, F-4(3/2) splitting along the series, etc.), that are correlated to J mixing effects, important for low symmetry systems and increasing from Y2O3 to Sc2O3. The energy levels of Sm3+ in centrosymmetric C-31 centers in Sc2O3, obtained by a time-resolved technique, along with the previous reported data on sesquioxides are also analyzed. (C) 2013 Elsevier B.V. All rights reserved.