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MA: Magnetismus

MA 7: Micro- and Nanostructured Magnetic Materials I

MA 7.11: Vortrag

Montag, 27. März 2006, 17:30–17:45, HSZ 03

Arrays of magnetic nano particles using self-organised semiconductor surfaces — •Nikolai Mikuszeit¹, Miguel Angel Niño¹, Julio Camarero¹, Juan José de Miguel¹, Rodolfo Miranda¹, Christian Hofer², Christian Teichert², Thomas Bobek³, and Stepan Kyrsta⁴ — ¹Dpto. Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain — ²Institut für Physik, Montanuniversität, A-8700 Leoben, Austria — ³Institut für Halbleitertechnik, RWTH-IHT, D-52056 Aachen, Germany — ⁴Lehrstuhl für Werkstoffchemie, RWTH-MCh, D-52056 Aachen, Germany

The self-organisation of semiconductor surfaces has been used to create arrays of magnetic nano particles [1]. The surface structure and magnetic properties are amongst others investigated by AFM and MOKE. In a first approach we use strain induced self-assembled SiGe surfaces as growth templates. Shadow deposition onto these surfaces results in elongated magnetic dots [2]. In a second approach the formation of self-organised hexagonal dots of GaSb surfaces, due to Ar⁺ sputtering, are used [3]. Deep trenches between the dots cut an embedded magnetic layer into discs. Both systems show dipolar coupling between the dots. To overcome the dipolar coupling a high magnetic anisotropy energy is required. In order to enhance the magnetic anisotropy, CoPt-multilayers with perpendicular anisotropy and Co/CoO in-plane systems are studied. The dot magnetic behaviour is compared to micromagnetic simulations.

[1] C. Teichert Appl. Phys. A 76, 653 (2003)

[2] A. M. Mulders et al. Phys. Rev. B , 71, 214422 (2005)

[3] S. Facsko et al. Science 285, 1551 (1999)