Electron paramagnetic resonance of Fe3+ in near-stoichiometric LiTaO3

Electron paramagnetic resonance (EPR) experiments on the dominant Fe3+ centre in near-stoichiometric LiTaO3 crystals grown by the double crucible Czochralski method are reported. A near complete roadmap of EPR positions was obtained, and transitions from two magnetically non-equivalent sites clearly resolved in the zx plane, perpendicular to the glide plane. This allowed accurate determination of C3 symmetry spin Hamiltonian parameters. Newman superposition model analyses of second and fourth order zero field splitting term parameters were performed to give further insight into the site of incorporation. The second order calculations provide evidence for Fe3+ substitution within the Li octahedron.