Regensburg 2007 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 11: Magnetic Thin Films I
MA 11.5: Vortrag
Dienstag, 27. März 2007, 11:15–11:30, H10
Pinning and exchange coupling in epitaxial SmCo5 films — Aarti Singh1, •Volker Neu1,2, Sebastian Fähler1,2, Konstantin Nenkov1, Ludwig Schultz1,2, and Bernhard Holzapfel1 — 1IFW Dresden, P.O. Box: 2270116, 01171 Dresden, Germany — 2Institute for Physics of Solids, Department of Physics, Dresden University of Technology, 01062 Dresden, Germany
Highly coercive SmCo5 thin films (Hc = 3.6 T) were epitaxially prepared by pulsed laser deposition on Cr buffered MgO(100) substrates with two orthogonal orientations of the easy axis in the film plane [1]. Magnetic hysteresis measurements for fields applied at different in-plane angles show two steps in the demagnetisation branch. These correspond to the switching of areas with different easy axes orientation at different applied fields. Both switching fields Hsw1 and Hsw2 follow an inverse cosθ behaviour, which points towards a pinning dominated magnetization process but also reveals an independent magnetisation switching for grains with perpendicular orientation. Thus the behaviour suggest, that the film consists of partially decoupled grains. On the other hand, a detailed remanence analysis results in a strong positive δJ, which is indicative of exchange coupling between grains. These two contradictory pictures can be merged by assuming that grains with parallel c-axis form a strongly coupled network which behaves independent from the orthogonal grain network during the reversal process.
[1] A. Singh, V. Neu, R. Tamm, K. Subba Rao, S. Fähler, W. Skrotzki, L. Schultz and B. Holzapfel, APL 87, 2005, 072505