Electronic structure of REFe2 (RE = Dy, Ho and Er) intermetallic compounds: Ab initio spin-density functional theory

Abstract

In this study, the structural, magnetic and electronic characteristics of the cubic MgCu2-type binary Laves phases REFe2 (RE = Dy, Er and Ho) compounds have been investigated. To describe the correlation effects with high accuracy, the spin density functional theory (DFT) was used within the generalized gradient approximation (GGA) to estimate the exchange correlation potential and the GGA + U (U: Hubbard parameter) calculations. The parameter of the lattice and magnetic moments at the equilibrium state were found to be in good agreement with the available experimental data. We have calculated the magnetic moments of RE (RE = Dy, Er and Ho) and Fe in their binary compounds, by using GGA and GGA + U methods. The value of the Fe magnetic moments was found to be higher than that of RE. The obtained results have also shown that the GGA + U method is the best to describe our systems. We have also projected the electronic structures and the spin-polarized density of states (DOS) of the RE-4f and Fe-3d orbital. The REFe2 compound has shown to exhibit a metallic behavior with a small spin-down electronic density of states at the Fermi level in both the GGA and GGA + U approximations.