Spectroscopic properties of rare-earth (RE) and transition-metal (TM) ions in orthorhombic symmetry sites in crystals are considered. Correlations between orthorhombic crystal field (CF) parameters are studied. The intrinsic limit on the asymmetry parameter λ = B 2 2/B 2 0 (k = B 22/B 20) is used to unify the six equivalent ways of presentation of CF parameters. Implications for analysis of the one-electron CF data as well as SCCF (spin-correlated CF) data are discussed, including the corresponding error analysis. Our results indicate that the SCCF data must be treated with caution. A multiple correlation fitting technique is suggested to increase the reliability of CF data. Correlations between several CF parameters sets for REBa2Cu3O7-x , RE2Fe14B, RE-garnets, RE:LaF3, and MnF2 are established. It is shown that the arbitrary ways of presentation of the experimental orthorhombic CF parameters should be replaced by a well defined standard form thus helping to avoid the present inconsistencies. The propose...
Read full abstract