Investigating the zero-field splitting parameters of 3d5 ions (Mn2+ and Fe3+) doped α-Al2O3 crystal

The characteristics of the local environment around paramagnetic centers formed by 3d5 ions (Mn2+ and Fe3+) in α-Al2O3 crystal are investigated using theoretical analysis. The zero-field splitting (ZFS) parameters (ZFSPs) for Mn2+ and Fe3+ ions located at the substitutional Al3+ sites and the interstitial sites are modeled using several modelling approaches through superposition model (SPM) and the fourth-order perturbation theory (PT) formula. The possible structural distortions resulting from Mn2+ and Fe3+ ions are determined around Al3+ sites with C3v symmetry and interstitial sites with D3d symmetry. The results are discussed in respect to the potential of the sites to be located by 3d5 ions and modelling approaches.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (50 K)Download as PowerPoint slideHighlights► Impurity structure for 3d5 ions is investigated theoretically in α-Al2O3. ► Both ZFSP D and CF parameters at the Al and interstitial sites (ISs) are calculated. ► The feasible structural distortions due to Mn+2 and Fe3+ ions are determined. ► It is confirmed that IS has potential to be occupied by 3d5 ions as much as Al3+ site.