COMPARATIVE-ANALYSIS OF ND-3+ (4F3) ENERGY-LEVELS IN 4 GARNET HOSTS

As many as thirty-seven 2S+1LJ multiplet manifolds of Nd3+(4f3) have been analyzed in the garnets Y3Al5O12 (YAG), Y3Sc2Al3O12 (YSAG), Gd3Sc2Ga3O12 (GSGG), and La3Lu2Ga3O12 (LLGG). The majority of Nd3+ ions substitute for Y3+, Gd3+, or La3+ ions in sites of D2 point-group symmetry in the lattice. Individual Stark levels within each manifold have been identified experimentally up to 40 000 cm-1 and compared with results obtained from a theoretical calculation. The model Hamiltonian includes Coulombic, spin-orbit, and interconfiguration interaction terms for the 4f3 atomic configuration of Nd3+ and crystal-field terms in D2 symmetry, including spin-correlated crystal-field (SCCF) contributions. The Hamiltonian was diagonalized within the complete 4f3 SLJMJ basis set which includes 364 states. Comparison between 148 (Nd:YAG), 140 (Nd:YSAG), 143 (Nd:GSGG), and 107 (Nd:LLGG) observed and calculated Stark levels (without SCCF) yields rms deviations of 18, 19, 17, and 16 cm-1, respectively. Results indicate that SCCF contributions yield modest improvement in the calculated value of the overall crystal-field splitting of the energy levels. © 1990 The American Physical Society.