Dresden 2009 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 12: Nanostructures at surfaces: Dots, particles, clusters I (magnetic)

O 12.3: Vortrag

Montag, 23. März 2009, 15:30–15:45, SCH A215

Ferromagnetism of magnetic nanodot ensembles promoted by substrate-mediated interaction — •Pavel A. Ignatiev¹, Nikolay N. Negulyaev², Alexey S. Smirnov³, Larissa Niebergal¹, Alexander M. Saletsky³, and Valeri S. Stepanyuk¹ — ¹Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany — ²Physics Department, Martin-Luther-University Halle-Wittenberg, 06099 Halle, Germany — ³Faculty of Physics, Moscow State University, 119899 Moscow, Russia

Recent experimental studies evidenced collective ferromagnetic behavior with high Curie temperatures in Fe nanodots assemblies created on Cu(111) surfaces by means of buffer layer assisted growth [1,2]. It was suggested that a substrate-mediated indirect RKKY-like exchange interaction between Fe dots was responsible for the magnetic order [2].

Here we present combined ab initio and kinetic Monte Carlo (kMC) investigations of the magnetic ordering in ensembles of Fe nanodots embedded in noble metal (Cu, Ag, Au) substrates. Exchange interactions in considered systems are calculated fully ab initio by means of the Korringa-Kohn-Rostoker Green's function method. kMC simulations based on this ab initio input revealed the ferromagnetic ordering in the ensemble of Fe nanodots.

[1] J. P. Pierce et al., Phys. Rev. Lett. 92, 237201 (2004).

[2] M. A. Torija et al., Phys. Rev. Lett. 95, 257203 (2005).