Theoretical studies of the Spin Hamiltonian Parameters for the orthorhombic Pr4+ ion in SrCeO3 crystal

The perturbation formulae of the Spin Hamiltonian Parameters (EPR parameters anisotropic gyromagnetic factors g(x), g(y), g(z) and hyperfine structure constants A(x), A(y), A(z)) for the lowest Kramers doublet of F-2(5/2) of 4f(1) ion in orthorhombic symmetry are established. In these formulae, the contributions of the covalence effects, the admixture between J=5/2 and J=7/2 states as well as the second-order perturbation are all included. The crystal field parameters for the studied Pr4+ center are calculated from the superposition model and the crystal structure data. Based on the perturbation equations and related parameters, the g factors g(x), g(y), g(z) and hyperfine structure constants A(x), A(y), A(z) for orthorhombic Pr4+ ion in SrCeO3 are calculated. The results are in reasonable agreement with the observed values. The results are discussed. (C) 2007 Elsevier B.V. All rights reserved.