Correlation effect on the electronic structure of RECo2 (RE= Gd and Eu) intermetallic compounds: A comparative study

Abstract

This work reports an ab initio study of the electronic and magnetic properties of the binary phases Laves GdCo2 and EuCo2 of MgCu2 type. The linearized augmented plane wave method with total potential was used (FP-LAPW). To estimate the exchange and correlation potential, we introduced the generalized gradient approximation (GGA) and GGA + U (with a Hubbard “U” parameter) to take into account the correlation effects. The results show that the obtained magnetic moments corroborate the data found in literature as well. Note that the GGA + U gave magnetic moments greater than those calculated using the GGA scheme. To obtain further insight into the type of states associated with each orbital, the projected densities of states of the 4f-Gd, 4f-Eu and 3d-Co orbitals were also calculated using GGA and GGA + U respectively, to obtain additional information on the electronic and magnetic properties of these compounds. This work highlights the role of the correlated electrons processing for an accurate description of these binary Laves phases compounds.