First-Principle Simulation of Ferromagnetism in Gd-Doped Mg2X (X=Si, Ge and Sn)

Abstract

Magnetic phase stability and electronic properties of Gd-doped Mg2X ([Formula: see text], Ge and Sn) were investigated by first-principle calculations based on density functional theory. The present calculations were performed using the Generalized Gradient Approximation (PBE-GGA) and the modified Becke–Johnson (mBJ-GGA). The 4[Formula: see text] electrons’ behavior has been investigated as a function of the Coulomb repulsion [Formula: see text] by varying it from 0[Formula: see text]eV to 8[Formula: see text]eV. The ground state properties for the pure compounds are consistent with experimental values and other theoretical data. All doped compounds are metallic and ferromagnetic with large Curie temperature values. It was found that both exchange potentials ([Formula: see text] and [Formula: see text]) provide a better description of the electronic structures of pure and doped systems than regular GGA and mBJ.