Spin and orbital contributions to surface magnetism in 3d elements.

Abstract

We have determined theoretically both the orbital and the spin contribution to the magnetic moment on the (001) surfaces of fcc Mn, bcc and fcc Fe, hcp Co, and fcc Ni. We used a surface geometry that corresponds to the bulk crystal structure (except for Mn) with no relaxation of the surface. In addition to enhanced spin moments at the surface we find that the orbital moment for surface states is greatly enhanced (sometimes by more than 100%). We also present calculations for different spin configurations in fcc Fe, and we find that two competing spin configurations exists. fcc Mn is found to have a surface spin moment slightly larger than the surface moment of bcc Fe. Detailed information from the calculations is presented, i.e., density of states, charge-density contour plots, and orbital-projected spin moments.