Year: 2008
Type: article
Abstract: The electron correlations in narrow energy bands are examined within the framework of the modified form of polar model.This model permits to analyze the effect of strong Coulomb correlation, inter-atomic exchange and correlated hopping of electrons and explain some peculiarities of the properties of narrow-band materials, namely the metal-insulator transition with an increase of temperature, nonlinear concentration dependence of Curie temperature and peculiarities of transport properties of electronic subsystem.Using a variant of generalized Hartree-Fock approximation, the single-electron Green's function and quasi-particle energy spectrum of the model are calculated.Metal-insulator transition with the change of temperature is investigated in a system with correlated hopping.Processes of ferromagnetic ordering stabilization in the system with various forms of electronic DOS are studied.The static conductivity and effective spin-dependent masses of current carriers are calculated as a function of electron concentration at various DOS forms.The correlated hopping is shown to cause the electron-hole asymmetry of transport and ferromagnetic properties of narrow band materials.
Source: Condensed Matter Physics
DOI: 10.5488/cmp.11.3.443
Authors: Didukh, Skorenkyy, Kramar
Institution: Ternopil Ivan Pului National Technical University
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W1998199243