Investigations on the g factors and local structure for the trigonal Ce3+ center in YAl3(BO3)4 crystal

Abstract

Abstract The perturbation formulae of the EPR gyromagnetic factors g // and g ⊥ for the lowest Kramers doublet of a 4f1 ion in trigonal symmetry are established. By using the above perturbation formulae, the anisotropic g factors and the local structure for the trigonal Ce3+ center in YAl3(BO3)4 crystal are theoretically studied. From the studies, this center is attributed to the impurity Ce3+ occupying the trigonal prism Y3+ site in YAl3(BO3)4. The Ce3+–O2− bond is found to undergo an angular variation Δθ(≈ 1.72°) related to the C3 axis. The calculated g factors based on the above impurity angular distortion display consistence with the measured results. The anisotropic g factors and the trigonal distortion of the Ce3+ center are analyzed with respect to the host Y3+ site in YAl3(BO3)4.