Regensburg 2010 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 16: Micro- and Nanostructured Magnetic Materials II
MA 16.2: Vortrag
Mittwoch, 24. März 2010, 10:30–10:45, H23
Magnetic Properties of Fe Wires on Vicinal Cu(111) at Finite Temperatures — •Hossein Hashemi1, Guntram Fischer1, Wolfram Hergert1, Valeri S. Stepanyuk2, Hasan Sadat Nabi3, and Rossitza Pentcheva3 — 1Department of Physics, University of Halle, Von-Seckendorff-Platz 1, 06120 Halle, Germany — 2MPI for Microstructure Physics, Weinberg 2, 06120 Halle, Germany — 3Departments of Earth and Environmental Sciences, University of Munich, Theresienstrasse 41, 80333 Munich, Germany
Vicinal surfaces on metals are very suitable templates to grow one-dimensional nanowires. It is known that Fe nanostripes grow on the upper terrace of a stepped Cu(111) surface. Mo, Guo et al. [1,2] have shown that, Fe adatoms form an atom chain embedded into the Cu substrate behind a row of Cu atoms at the descending step. Then a second chain of Fe atoms is formed on top of the embedded Fe chain. In this work, density functional theory (DFT) is applied to describe the structural and magnetic properties of Fe chains and wires consisting of two Fe chains embedded in the Cu(111) surface. We determine both the direct exchange interaction within the Fe wires as well as the indirect exchange interactions between parallel Fe chains as a function of the interchain distance. Furthermore, the magnetocrystalline anisotropy energy is calculated. Exchange interactions and anisotropy extracted from the ab initio calculations are used in a classical Heisenberg model. Monte Carlo simulations are done to investigate the finite temperature properties of the systems. [1] Yina Mo, et al., PRL 94, 155503 (2005). [2] J. Guo et al., Phys. Rev. B 73, 193405 (2006).