COMPARATIVE ANALYSES OF ND-3+ (4F3) ENERGY-LEVEL STRUCTURES IN VARIOUS CRYSTALLINE HOSTS

We have performed an in-depth analysis of the energy-level structures in seven Nd3+ (4f3) crystal systems: [Nd(H2O)9] . 3CF3SO3, Nd3+:Cs2NaGdCl6, four Nd3+-doped garnets (Nd3+:A3B5O12), and Nd3+:CsCdBr3. A model Hamiltonian employing 20 free-ion operators and the appropriate one-electron crystal-field interaction operators (plus selected two-particle correlation crystal-field (CFF operators) was diagonalized within the full 364 SLJM(J) basis of the f3 electronic configuration. Ample spectroscopic experimental data allowed us to use least-squares fitting routines to produce a crystal-field energy-level structure for Nd3+ in each host. Particular attention is given in this report to some differences in the values of the free-ion parameters among the seven hosts and to the strong effects of three CCF operators on crystal-field level ordering in specific multiplets. The effects of CCF operators (originally proposed by Judd and later studies by Reid) are shown to be a small perturbation on the standard one-particle (B(q)k) formalism.