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

摘要

Optical Zeeman effect measurements are performed at liquid helium temperature on Nd3+ ions in weakly doped YVO4 crystals in the range 11 350-11 390 cm(-1) of the F-4(3/2) --> I-4(9/2) neodymium transitions. This study provides confirmation that the concentration dependent satellite lines accompanying the optical transitions are due to ferromagnetically coupled pairs of Nd3+ ions in undistorted Y3+ sites of D-2d point site symmetry. Nonlinear Zeeman splittings are observed in the range of experimental magnetic fields. These splittings are compared with those simulated from crystal field calculations by introducing the Zeeman Hamiltonian into the secular determinant before diagonalization. A reasonably good agreement between the calculated and experimental g-values is obtained, confirming that the exchange coupled neodymium pairs experience no crystal field perturbations. [References: 23]