Ab Initio Study of Y Doping Effects on Electronic Structure and Magnetic Properties in Rh₂Mn_1–xY_xZ (Z = Ge, Sn)

The electronic and magnetic properties of the doped Heusler alloys Rh₂Mn_1–xY_xGe and Rh₂Mn_1‒xY_xSn (x = 0, 0.25, 0.5, 0.75, 1) have been performed within the first-principles density functional theory (DFT) using the generalized gradient approximation (GGA) scheme, with the disordered structures. The calculated results reveal that with increasing Y content, the lattice parameter slightly increases except x = 0.5 for Rh₂Mn_1–xY_xSn. For both quaternary alloys it is found the local moments of Mn(Y) and Rh basically show a linear decreasing trend with increasing doping concentration and the total magnetic is negligible for x = 1. The minority-spin band component at the Fermi level for Rh₂Mn_1–xY_xGe and Rh₂Mn_1–xY_xSn decreases while the majority-spin band component at the Fermi is less affected with the substitution of Y atoms for Mn atoms.