Dresden 2011 – scientific programme

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MA: Fachverband Magnetismus

MA 31: Magnetization Dynamics III

MA 31.5: Talk

Wednesday, March 16, 2011, 12:00–12:15, HSZ 403

Evolution from superparamagnetism to ferromagnetism in nanostructures studied by first-principles magnetization dynamics — •Danny Böttcher^{1, 2}, Arthur Ernst¹, and Jürgen Henk¹ — ¹Max Planck Institute of Microstructure Physics, Halle, Germany — ²Martin Luther University Halle-Wittenberg, Halle, Germany

With respect to the ongoing miniaturization of spintronic devices, the magnetic stability of nanostructures becomes increasingly important. These systems have, thus, to be described theoretically on the atomic length-scale and on the femtosecond time-scale.

We report on an investigation of atomistic magnetization dynamics by means of the stochastic Landau-Lifshitz-Gilbert equation. The exchange and anisotropy parameters of the spin Hamiltonian are computed from first principles. For the paradigmatic Co nanoislands on Cu(111), we focus on the evolution from superparamagnetic (noncollinear) states to a ferromagnetic (collinear) state in dependence on temperature, island size, and external magnetic field. It turns out that corners and edges of the triangular islands act as nucleation centers of magnetic nanodomains.