Local electronic structure of intrinsic defects and impurities at the Fe(001) surface

Ab-initio calculations for the electronic structure and magnetic properties of intrinsic defects and foreign impurities (oxygen and gold) on the Fe(001) surface using the LSW method and the super-cell approach are presented. The calculations show that the Fe intrinsic defects have different local density of states. The magnetic moment of the Fe substrate layer under the defects increases with decreasing number of nearest neighbors of the surface, while the magnetic moment of the Fe defects decreases with decreasing number of nearest neighbors on the surface. The oxygen impurities have rather narrow (2p) bands at about 6.0 eV below the Fermi energy. The influence of oxygen impurities on the Fe(001) surface states near the Fermi energy is remarkably insignificant. Both gold and oxygen impurities have small magnetic moments parallel to the surface iron.