IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Tuesday Sessions
       Session SS3-TuP

Paper SS3-TuP9
Cs Adsorbed Structure and Change of Magnetism in fcc Co Thin Films Grown on Cu(001) Surfaces

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Adsorption/Desorption Poster Session
Presenter: F. Komori, ISSP, University of Tokyo, Japan
Authors: F. Komori, ISSP, University of Tokyo, Japan
M. Xu, ISSP, University of Tokyo, Japan
T. Iimori, ISSP, University of Tokyo, Japan
K. Lee, ISSP, University of Tokyo, Japan
M. Yamada, ISSP, University of Tokyo, Japan
K. Nakatsuji, ISSP, University of Tokyo, Japan
Correspondent: Click to Email
Magnetic properties of ferromagnetic thin films are often largely modified by adding foreign atoms on the surface. Some of the adsorbed non magnetic atoms or molecules make the magnetization small and change the magnetic anisotropy. To study the effect of Cs adsorption on magnetism as a simple metal, we have deposited Cs on a fcc Co(001) thin film grown on a clean Cu(001) surface, and measured correlation between the ordered structure of Cs adsorbed surface and the ferromagnetic hysteresis loops of the thin film. A fcc Co thin film (about 5 mono-atomic layers thick) was prepared on a clean Cu(001) surface in an ultra-high vacuum, and the surface structure was monitored by LEED with increasing the amount of adsorbed Cs both at 300 K and at 100 K. In both cases, a ring pattern appeared at the first stage of the deposition, and then quasihexagonal LEED spots with two domains were observed. These features are similar to the Cs adsorption on a clean Cu(001) surface, and the distance between the adjacent Cs atoms on the Co surface is the same as that on the clean Cu surface. The relation between the ferromagnetic hysteresis loops and the amount of the adsorbed Cs was in situ studied using magneto-optical Kerr effect. Cs adsorption does not change the magnitude of the magnetization. This is quite in contrast with hydrogen adsorption on the same surface. With increasing the amount of Cs on the surface, the coercive force once decreases and then increases at 100 K while it is almost constant after the initial decrease at 300 K. These are interpreted the increase of the uni-axis magnetic anisotropy due to the steps on the surface at 100 K..