Charge and magnetic order in the 2D Falicov-Kimball model with Hund coupling at finite temperatures

Abstract

We perform a simplified analysis of finite temperature properties of the generalized Falicov-Kimball model with Hund coupling. The model is studied on the square lattice for fixed values of \emph{f-electron} and \emph{d-electron} densities $\rho_f=1/2$, $\rho_d=1$. Using an approxiamte scheme we estimated free energies of the following three phases: the charge and spin ordered (SCO), the charge ordered (CO) and the non-ordered (NO). Comparing the free energies we detected phase transitions and found how the transition temperatures depend on the on-site interaction parameters. It appears, that the transition temperture between SCO and CO is much lower than between CO and NO, but their maximum values are attained at values of coupling constants very close to each other.