Structural, electronic, and magnetic properties of an open surface: Fe(111)

Structural, electronic, and magnetic properties of the rough Fe(111) surface, which is open in the surface plane but tight in the perpendicular direction, were calculated using the local-spin-density full-potential linearized augmented-plane-wave (FLAPW) total-energy method. Large multilayer relaxation was found in the top four layers; the calculated net surface relaxation, -0.2, is in excellent agreement with experiment. Although Fe(111) and Fe(100) surface atoms possess the same coordination number, their magnetic moments in Fe(111), 2.60μB, are significantly smaller than that for Fe(100), 2.98μB-indicating the sensitivity of Fe magnetism to its environment. Spin polarization was found to be very important for the determination of the work function (4.44 and 4.81 eV for ferromagnetic and paramagnetic cases, respectively). Three surface states were found; two of them have been observed in a recent photoemission experiment.