AVS 50th International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI+TF-WeA

Invited Paper MI+TF-WeA7
Ultrathin Magnetic Layers Electrodeposited on Au(111)and Related Technological Substrates

Wednesday, November 5, 2003, 4:00 pm, Room 316

Session: Magnetic Thin Films
Presenter: P. Allongue, CNRS, France
Authors: P. Allongue, CNRS, France
F. Maroun, CNRS, France
J.E. Schmidt, UFRGS
A. Gundel, UFRGS
M.L. Munford, UFSC
T. Devolder, IEF, France
Correspondent: Click to Email
Magnetic properties such as interface perpendicular anisotropy (PMA) is strongly depending on the coupling between the substrate, generally a noble metal, and the ultrathin ferromagnetic layer. Both the film and interface structures are also critically influencing the strength of PMA. We recently showed that electrodeposited Cu/Co/Au(111) structures exhibit strong PMA due to an excellent 2D epitaxial growth of cobalt and some residual elastic stress at the interface. This talk will be divided into two parts. In the first one, I will present in situ structural and magnetic characterizations of M / Au(111) ultrathin layers, with M = Co, Ni and Fe using STM, EXAFS and real time in situ magnetic characterizations (AGFM and PMOKE) with sub-monolayer sensitivity. It will be shown that the latter measurements, performed in the electrolytic environment, yield new information regarding the relationship between the deposition conditions (potential, pH etc.) and the magnetic state of layers. While Co and Fe layers are ferromagnetic at submonolayer coverages, results show that Ni layers become ferromagnetic only after the deposition of 5-6 monolayers. By proper adjustment of the deposition condition, so as to avoid dramatic H-incorporation, ultrathin ferromagnetic Ni layers may however be prepared. The strength of PMA at Co/Au(111) layers will be discussed in details. The second part of the talk will address the deposition of cobalt on epitaxial Au(111) layers on vicinal H-Si(111) surfaces. We are able to prepare ultraflat Au films or Au films consisting in nm-sized dots aligned along the step edges. As a consequence, we may prepare Co/Au/Si films with quite different magnetic properties. For instance, in the case of Au dots in plane anisotropy is obtained and it is possible to vary the coupling between lines of Co dots by changing the Si miscut. These results will be discussed in details at the conference.