Über den Jahn-Teller-Effekt des Cu2+-Ions in oxidischen Festkörpern

Abstract

The remission spectra of a number of Cu2+-containing oxidic solids in the region between 3500 and 25 000 cm-1 were found to show always — independent of the macroscopic lattice-symmetry — the typical three-band-structure expected for tetragonally distorted octahedra. It could be derived from the spectra of the perovskite-mixed-crystals Sr2(CuχZni _xMe)O6 [Me=W6+, Te6+] (0<χ≦1) hat these three bands have to be assigned to the transitions B1g → A1g , -→ B2g and → Eg with increasing energy. A crystal field formalism is developed, which allows a quantitative treatment of the spectra in correspondence with crystallographic data. The calculated ligand-field-parameters Δ do not differ much from those of Ni2+ and Co2+ in the same host lattices.