Regensburg 2010 – scientific programme

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MA: Fachverband Magnetismus

MA 30: Electron Theory of Magnetism

MA 30.4: Talk

Thursday, March 25, 2010, 17:45–18:00, H22

An ab-initio description of the magnetic shape anisotropy — •Sven Bornemann, Jan Minár, Jürgen Braun, and Hubert Ebert — Department Chemie und Biochemie, LMU München, 81377 München, Germany

For magnetic transition metal systems with reduced dimensionality and low symmetry the shape anisotropy becomes a significant contribution to the magnetic anisotropy. In fact, it can reach the same order of magnitude as the spin-orbit induced anisotropy. So far, the shape anisotropy has always been treated as a classical interaction between magnetic dipoles while the spin-orbit anisotropy has been determined by relativistic band structure calculations. It is uncertain, however, whether such an inconsistent treatment of the two anisotropy contributions is still valid for low-dimensional nano structures such as magnetic thin films, wires or clusters where the magnetic easy axis can depend strongly on the interplay between these two contributions. As an alternative to the classical approach an ab-initio description of the shape anisotropy has been developed. This is achieved by including the Breit interaction, being the natural cause of the shape anisotropy, in the Dirac-equation set up within the framework of spin density functional theory. We have implemented this approach using the fully relativistic KKR band structure scheme. We will present the details of our implementation and show results for the shape anisotropy of thin Fe films on Au(001) as well as for free-standing Fe and Co wires in comparison with the classical treatment.