Investigations of the anisotropic g-factors for the Er3+ doped YBa2Cu3Oy (6<y<7) superconductor

The anisotropic g factors g// and g⊥ for the tetragonal Er3+ center associated with Er3+ on Y3+ site in YBa2Cu3Oy (6<y<7) superconductor are investigated by using the second-order perturbation formulas of g factors for a 4f11 ion in tetragonal symmetry. In these formulas, the contributions to the g factors from the second-order perturbation and the admixture of different energy levels are considered. The related crystal field parameters are calculated from the superposition model parameters obtained for similar tetragonal [ErO8]13− clusters in some zircon compounds. The reasonableness of the results is discussed.