Electron magnetic resonance studies ofFe3+ions inBaTiO3: Implications of the misinterpretation of zero-field splitting terms and comparative data analysis

Abstract

The recent electron magnetic resonance studies (EMR) studies [Decker et al., Phys. Rev. B 66, 174103 (2002)] of ${\mathrm{Fe}}^{3+}$ ions in $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_{3}$ indicate a pronounced discrepancy concerning the values of the fourth-rank zero-field splitting (ZFS) parameters from various authors. Our reanalysis of the ZFS terms for the pertinent symmetry cases reveals a misinterpretation of the ZFS parameters by Decker et al. This leads to different ZFS parameter relationships than those originally assumed. Reinterpretation of their EMR results, using the proper conversions relations to the prevailing conventional ZFS notation derived by us, removes the discrepancy in question. This exemplifies the pitfalls arising from such misinterpretation. The ZFS parameters for ${\mathrm{Fe}}^{3+}:\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_{3}$ in various phases are reanalyzed, reconverted as appropriate, and presented in a unified way together with the $g$-factors. Comparative analysis of the available EMR data for ${\mathrm{Fe}}^{3+}:\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_{3}$ reveals also other inconsistencies in the ZFS notations occurring in the literature, implications of which for data interpretation are discussed.