AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeM

Paper MI-WeM2
Structure and Magnetic Anisotropy of Ultrathin Co Films on Au(111) Vicinal Substrates

Wednesday, November 17, 2004, 8:40 am, Room 304A

Session: Magnetic Nanostructures
Presenter: A. Tejeda, Université Paris 7, France
Authors: A. Tejeda, Université Paris 7, France
G. Baudot, Université Paris 7, France
A. Coati, Université Paris XI, France
Y. Garreau, Laboratoire Utilisation Rayonnement Electromagnetique, France
Y. Girard, Université Paris 7, France
J.P. Jamet, Université Paris XI, France
V. Repain, Université Paris 7, France
S. Rohart, Université Paris 7, France
S. Rousset, Université Paris 7, France
Correspondent: Click to Email
Nanostructured systems with magnetization along the surface normal are of technological interest for magnetic storing devices. We have studied ferromagnetic films of Co as they exhibit a strongly enhanced magnetic anisotropy with an easy axis perpendicular to the surface plane. Vicinal surfaces are a system model to control the roughness of the ferromagnetic films. We have deposited Co ultra-thin films on vicinal substrates of Au(111) in order to study the relationship between structure and magnetic properties. STM and Grazing Incidence X-ray Diffraction studies have been performed to determine the surface structure. X-ray diffraction shows that the vicinality of the substrate strongly modifies the Co film structure. While Co/Au(111) presents hcp structure, fcc Co is found on Au(233). Growth on an intermediate surface as Au(788) originates a structure with stacking faults. In a second part, we report on a magneto-optical study of the magnetic properties of these cobalt ultrathin films. In vicinal surfaces, the transition of the magnetisation from out-of-plane to in-plane orientation as a function of Co coverage appears in a more progressive way and at lower coverages than in Co/Au(111). Ex-situ measurements on samples passivated with a gold layer show an helicoidal reorientation transition. The easy axis of the magnetization changes from out-of-plane to in-plane, step parallel orientation. These results will be discussed in the light of the precise structural knowledge of these films.