Optical and ESR Characterization of Transition Atoms in CuAlS2

The optical and ESR properties of the CuAlS2 single crystals, doped with transition atom (TA) elements of the iron group, i.e. Ti, V, Cr, Mn, Fe, Co, and Ni, have been studied. It has been found that TA impurities in the CuAlS2 host lattice are present in their different valence states, the relative concentrations of these impurities in each valence state being dependent on the position of the Fermi level in the band gap of the host compound in relation to deep energy (demarcation) levels introduced by TA ions.