Influence of substrate roughness on the magnetic properties of thin fcc Co films
Steinmuller SJ., Vaz CAF., Ström V., Moutafis C., Gürtler CM., Kläui M., Bland JAC., Cui Z.
We present a study of the influence of substrate roughness on the magnetic properties of thin fcc Co films (7 and 17 nm thick) grown on Cu (001) Si (001). A significant decrease in cubic anisotropy with increasing film roughness was observed with Brillouin light scattering. In addition, the rougher samples exhibited a substantial broadening of the spin wave peaks. Both effects were found to be more pronounced for the thinner Co layers. We propose a magnetic configuration with the magnetization following coherently the substrate morphology ("undulating" state) resulting in the absence of magnetic surface charges. This configuration gives rise to a reduction in the magnetic anisotropy of epitaxial thin films, in good qualitative agreement with the experimental observations. © 2007 American Institute of Physics.