Modeling zero-field splitting parameters for dopant Mn2+ and Fe3+ ions in anatase TiO2 crystal using superposition model analysis

Abstract

The local environment around Fe3+ and Mn2+ ions doped into anatase TiO2 crystal is investigated and interpretation of EPR data, suggesting remote charge compensation, is provided. Using superposition model, the zero-field splitting (ZFS) parameters are modeled for Fe3+ and Mn2+ at the substitutional Ti4+ and interstitial sites (D-2d). Several approaches are used to match the modeled b(2)(0) ZFS parameter with experimental values and thus to discriminate between various structural models. Theoretical predictions of the b(4)(q) parameters are also provided and tentative matching with experimental data is considered. The feasible values of the structural distortion parameters are predicted. The uniqueness and thus reliability of the predicted ZFS and distortion parameters are discussed. (C) 2011 Elsevier B. V. All rights reserved.