Electronic spectrum of cobalt(II) in ZnWO4 and MgWO4 at 4.2 K

Abstract

The ligand-field spectrum of Co^II has been measured in crystals of MWO₄(M = Zn, Mg) from 5000 to 30 000 cm^–1. Spectra were measured with light incident on the (100) and (010) faces with the electric vector parallel to all three crystallographic axes at 300, 77 and 4.2 K. The splittings and intensities of the bands in different polarizations are interpreted in terms of a major C_2v and a minor C₂ perturbation of the octahedral site. Most of the observed intensities are derived from the static low-symmetry distortion but the effects of vibronic interaction and of spin–orbit coupling are also discussed.