The electron correlations in narrow energy bands are examined within the framework of the modi ed form ofudpolar model. This model permits to analyze the effect of strong Coulomb correlation, inter-atomic exchangeudand correlated hopping of electrons and explain some peculiarities of the properties of narrow-band materials,udnamely the metal-insulator transition with an increase of temperature, nonlinear concentration dependence ofudCurie temperature and peculiarities of transport properties of electronic subsystem. Using a variant of generalizedudHartree-Fock approximation, the single-electron Green's function and quasi-particle energy spectrum ofudthe model are calculated. Metal-insulator transition with the change of temperature is investigated in a systemudwith correlated hopping. Processes of ferromagnetic ordering stabilization in the system with various forms ofudelectronic DOS are studied. The static conductivity and effective spin-dependent masses of current carriersudare calculated as a function of electron concentration at various DOS forms. The correlated hopping is shownudto cause the electron-hole asymmetry of transport and ferromagnetic properties of narrow band materials.
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