Optical Zeeman effect measurements on isolated and ferromagneticallycoupled Nd3+ ions in weakly doped YVO4 crystals: evidencefor lack of crystal field perturbations in ion pair interactions

Abstract

Optical Zeeman effect measurements are performed at liquid helium temperatureon Nd3+ ions in weakly doped YVO4 crystals in the range11 350-11 390 cm-1 of the 4F3/2→ 4I9/2neodymium transitions. This study provides confirmation that the concentrationdependent satellite lines accompanying the optical transitions are due toferromagnetically coupled pairs of Nd3+ ions in undistorted Y3+ sites of D2d point site symmetry. Nonlinear Zeemansplittings are observed in the range of experimental magnetic fields. Thesesplittings are compared with those simulated from crystal field calculationsby introducing the Zeeman Hamiltonian into the secular determinant beforediagonalization. A reasonably good agreement between the calculated andexperimental g-values is obtained, confirming that the exchange coupledneodymium pairs experience no crystal field perturbations.