SATELLITE LINES IN THE OPTICAL-ABSORPTION SPECTRA OF DOPED (LA, PR)CL3-CRYSTALS .1. ENERGY-LEVELS AND ZEEMAN-EFFECT OF NON-KRAMERS IONS IN A DISTORTED HEXAGONAL LATTICE

By substitution of an impurity ion, A3+, for a trivalent La3+-ion, symmetric and asymmetric distortions may be produced in the lattice of the anhydrous lanthanum trichloride. In LaCl3 doped with Pr3+-ions at very low concentrations, these distortions give rise to Pr3+ satellite levels, the energy shift and Zeeman effect of which are calculated in a first order approximation. A survey is given of the possible types of single and double perturbations produced by substitution of one or two impurity ions in the neighbourhood of a non-Kramers ion in a hexagonal lattice of the LaCl3-type. The results are quite general for non-Kramers rare-earth ions on hexagonal sites in any other lattices. © 1979 Springer-Verlag.