Origin and peculiarity of electron spectrum of magnetic superconductors with transition ions

A scheme of constructing the energy-band structure of semiconductors containing the transition-metal ions is proposed. The scheme takes into account both the symmetry features of the lattice and the multielectron nature of d-orbitals. It is shown by an example of chromium-chalcogenide spinels that the dispersion curves of the electron spectrum calculated in terms of the model proposed agree with the results of the galvanomagnetic and optical experiments. 35 refs.; 5 figs.; 1 tab