Theoretical studies of the g factors and local structure for the rhombic Fe center in NaF

The anisotropic g factors and local structure for the rhombic Fe⁺ center in NaF are theoretically studied using the perturbation formulas of the g factors for a rhombically distorted octahedral 3d⁷ cluster. The impurity Fe⁺ is found not to occupy exactly the host Na⁺ site in NaF but to experience the off-center displacement of about 0.28 Å along 1 1 0] axis due to size mismatch substitution. The calculated g factors based on the above impurity displacement show reasonable agreement with the experimental data. The local structure of the Fe⁺ center is discussed.