Absorption Spectra of Transition Ions in CdS Crystals

The low-temperature optical absorption spectra of single crystals of wurtzite CdS containing impurity ions of the first transition series and one rare-earth ion, ytterbium, were studied in the range of 4.5 to 0.4 {μ}. The main features of the spectra were found to be in good agreement with a cubic crystal field model, while structure found in the spectral bands of nickel and cobalt impurities could be described by a simple, first-order treatment using the free ion spin-orbit coupling constants. The relevant crystal field parameters, the site symmetry, and formal charges of the impurity ions were determined where possible.