Electron paramagnetic resonance of Fe3+ in LiNbO3 -: art. no. 224111

We report electron paramagnetic resonance (EPR) experiments on the dominant Fe3+ center in high-quality near stoichiometric LiNbO3 grown from a Li/Nb ratio controlled melt. Symmetry related line splittings were clearly resolved and allowed unambiguous determination of the relative signs and magnitudes of the fourth-order trigonal zero field splitting (ZFS) spin-Hamiltonian (SH) parameters. Two conflicting EPR C-3 symmetry SHs for this center have been previously reported. Approximate agreement was found with that obtained for near-stoichiometric LiNbO3 grown using a K2O flux [G. I. Malovichko , J. Phys.: Condens. Matter 5, 3971 (1993)]. Extensive superposition model calculations of ZFS-SH terms showed that small displacement from either the Li or the Nb host site allowed the experimental rank-2 parameter value to be reproduced. Hence, on the basis of the EPR ZFS values alone, it is not currently possible to distinguish between possible C-3 incorporation sites within either the Li or Nb octahedra.