Theoretical investigations on the spin Hamiltonian parameters for Er3+ ion in LiYF4

The spin Hamiltonian parameters g(parallel to), g(perpendicular to), A(parallel to) and A(perpendicular to) for Er3+ ion in LiYF4 are investigated by using the perturbation formulas of these parameters for a 4f(11) ion in tetragonal symmetry. In these formulas, the contributions to the spin Hamiltonian parameters from the second-order perturbation terms and the admixtures of different states are considered. The relevant crystal field parameters are calculated from the superposition model and the local structural parameters of the Y3+ site occupied by impurity Er3+. The theoretical optical spectra within I-4(15/2) and I-4(13/2) states and the spin Hamiltonian parameters obtained in this work are consistent with the observed values. (C) 2004 Elsevier B.V. All rights reserved.