Low-dimensional nanostructures of magnetic metals on noble substrates have attracted considerable attention due to the fundamental interest of the enhanced magnetic moment [1-2]. In addition, the ever increasing bit density drives the need for a more thorough understanding of magnetism in the recording media [3]. Important role of perimeter atoms in supported islands has been shown recently. Co nanostructures on Pt(111) present a uniaxial out-of-plane magnetization which is entirely caused by edge atoms having 20 times more anisotropy energy than their bulk and surface counterparts [4]. Self-organized growth enables to achieve very narrow islands size distribution. This allows to study magnetic properties of nanostructures by using averaging technique such as Magneto-optical Kerr effect (MOKE) experiments. We will present variable MOKE and STM experiments of ordered Co nanodots deposited on Au(111), surrounded and covered by gold atoms. Different experiments varying the Co deposition, Au coverage and substrate temperature will be discussed in order to understand the Co nanodots magnetism and the effect of gold coverage.
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[2] R. Richter, J.G. Gay, J.R. Smith, Phys. Rev. Lett. 54 (1985) 2704.
[3] M. L. Plumer, J. van Ek and D. Weller. The Physics of Ultra-High-Density Magnetic Recording. Springer Series in Surface Sciences vol 41. Springer editions (Berlin, 2001).
[4] S. Rusponi, T. Cren, N. Weiss, M. Epple, P. Buluschek, L. Claude and H. Brune, Nature Materials 2 (2003) 546.
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