Exchange splitting of the Cr, Fe and Mn 3s XPS spectra in some ternary magnetic semiconductor sulphides

X-ray photoelectron spectroscopy (XPS) was used to analyse the exchange splitting of the 3s core levels of the 3d transition metals in the magnetic semiconductor single crystals CdCr2S4, MnCr2S4, FeCr2S4, Fe0.5Cu0.5Cr2S4 and polycrystal ZnCr2S4. A well defined splitting of the Cr, Fe and Mn 3s core levels has been found. No splitting of the Cu 3s line was observed. The values of the local magnetic moments and the valence configurations of the ions are discussed. The Cr ions are shown to be in a 3d3 state in all the studied compounds. The Fe ions are considered to be in a 3d6 state in the FeCr2S4 compound. In the MnCr2S4 a reduced value of the splitting for Mn2+ was observed. The Cu ions are in a diamagnetic 3d10 configuration in the Fe0.5Cu0.5Cr2S4 crystal.