Gd impurities effect on $$\hbox {Co}₂\hbox {CrSi}$$ Co 2 CrSi alloy: first-principle calculations

First-principle calculations have been performed to study Gd impurities doping effect on the physical properties of the Heusler half-metallic ferromagnet (hbox {Co}₂hbox {CrSi}) using the density functional theory in the local spin density approximation with an additional Hubbard correlation term for the rare-earth 4f states. The results show that the gadolinium moment is aligned antiparallel to that of transition metal atoms for both (hbox {Co}₁₆ hbox {Cr}₇ hbox {GdSi}₈) and (hbox {Co}₁₅hbox {GdCr}₈hbox {Si}₈). The analysis of the doped material band structures shows that the half-metallic properties are completely conserved if Gd substitutes Cr atoms, while the minority-spin gap is filled and half-metallicity is lost when Gd substitutes Co atoms.