Electronic and magnetic properties of DyFe$_{4}$Ge$_{2}$ alloys near a phase transition

The first-principles studies have been performed for the electronic and magnetic properties of DyFe$_{4}$Ge$_{2}$ alloys near the $P4_2/mnm-Cmmm$ phase transition. The calculations are carried out in a local spin density approximation taking into account the Coulomb interaction within the limit of strong localization in a mean field approximation. The electronic and magnetic properties of the tetragonal structure are shown to be weakly changed in the dependence on the Coulomb and exchange interactions and also on the choice of the approximations. In the case of the orthorhombic structure, a change in the parameters of the Coulomb and exchange interactions leads to a change in the magnetic ordering: from the ferromagnetic to ferrimagnetic in the strong localization limit and from the ferromagnetic to paramagnetic in the mean field approximation.