Theoretical interpretation of the EPR parameters for Dy3+ ion in LuPO4 crystal

Based on the superposition model, in this paper the EPR parameters g(\) and gperpendicular to of Dy3+, and the hyperfine structure constants A(\\) and A(perpendicular to) Of (161) Dy+ and Dy-163(3+) in LuPO4 crystal are calculated by perturbation formulas from the crystal-field theory. In the calculations, the contributions of various admixtures and interactions such as J-mixing, mixtures among states with the same J-value, two order perturbation, covalency as well as local lattice relaxation are considered. The calculated results agree reasonably with the observed values.