A careful analysis of the electron paramagnetic resonance spectra of Fe3+ ions in this material was carried out in order to resolve the weaker lines. Eight additional sets of fine-structure lines were identified, and their respective spin-Hamiltonian parameters were determined. The 8 magnetically inequivalent Fe3+ sites were attributed to two Ti sites. Two different centers, which arose from Fe3+ ions at the above Ti sites, were explained in terms of differing charge compensations. It was suggested that a vacancy of the first-neighbor O simultaneously played the role of a divalent positive charge compensator for two Fe3+ ions at the adjacent Ti sites.

S.W.Ahn, S.H.Choh: Journal of Physics - Condensed Matter, 1998, 10[2], 341-8