Electronic structure of GdX2 (X=Fe, Co and Ni) intermetallic compounds studied by the GGA+U method

Abstract The electronic and magnetic properties of the ferromagnetic laves-phase GdX 2 (X = Fe, Co and Ni) intermetallic compounds were calculated by using an all-electron full-potential linear muffin–tin orbital method (FP-LMTO) within GGA and GGA + U. The so-called GGA + U method is applied to properly treat the Gd–4f electron in the electronic structure calculation. The GGA improves the agreement between experiments and calculations for the lattice constants; however the GGA + U overestimates them, but gives a better representation of the band structure, density of states and magnetic moments compared to GGA alone. The reduction of the Co and Ni magnetic moments in the GdCo 2 and GdNi 2 compared to that in pure metals is due to the different localization strength of the transition metal and the same reason in the enormous reduction of the Curie temperatures.