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MA: Fachverband Magnetismus

MA 21: Magnetic Thin Films II

MA 21.4: Vortrag

Mittwoch, 27. Februar 2008, 14:45–15:00, H 1012

Temperature Dependence of Magnetic Order in Fe/(Ga,Mn)As studied by Monte Carlo Simulations — •Svitlana Polesya¹, Jan Minar¹, Hubert Ebert¹, and Christian Back² — ¹LMU München, Dept. Chemie und Biochemie/Phys. Chemie, Butenandtstrasse 11, D-81377 München, Deutschland — ²Institut für Experimentelle Physik, Univ. Regensburg, Deutschland

The magnetic order of the heterogeneous interface system (GaMn)As/Fe at finite temperatures has been studied by Monte Carlo simulations. The ground state magnetic properties were determined within ab initio electronic structure calculations using the SPR-TB-KKR Green’s function method. All calculations have been performed for the semi-infinite system of (GaMn)As with 5 % Mn covered by a 7 ML Fe film. The temperature dependent properties of this system (with and without external magnetic field) have been studied using MC simulation. The exchange coupling within the Fe and (GaMn)As subsystems were found to be dominantly long-range ferromagnetic whereas the coupling of Fe and Mn moments close to the interface is strongly antiferromagnetic. The Monte Carlo simulations lead to a Curie temperature of about 1000 K for the Fe film. Within the (GaMn)As subsystem due to the polarisation induced by the Fe film the average magnetisation at room temperature is still about 70 % of its T = 0 value for several layers close to the interface. These results are in full agreement with recent experimental findings.