360°domain wall generation in the soft layer of magnetic tunnel junctions.pdfVIP

APPLIED PHYSICS LETTERS 92, 072501 2008 360° domain wall generation in the soft layer of magnetic tunnel junctions M. Hehn, D. Lacour,a F. Montaigne, and J. Briones Laboratoire de Physique des Matériaux (LPM), Nancy-Université, CNRS, Boulevard des Aiguillettes, B.P. 239, F-54506 Vandœuvre lès Nancy, France R. Belkhou, S. El Moussaoui, and F. Maccherozzi Synchrotron SOLEIL, L’Orme des Merisiers Saint-Aubin, 91192 Gif-sur-Yvette, France and Synchrotron ELETTRA, AREA Science Park, 34012 Basovizza, Trieste, Italy N. Rougemaille Institut Néel, CNRS and Université Joseph Fourier, 25 Rue des Martyrs, B.P. 166, F-38042 Grenoble Cedex 9, France Received 20 November 2007; accepted 8 January 2008; published online 21 February 2008 High spatial resolution x-ray photoemission electron microscopy technique has been used to study the influence of the dipolar coupling taking place between the NiFe and the Co ferromagnetic electrodes of micron sized, elliptical shaped magnetic tunnel junctions. The chemical selectivity of this technique allows us to observe independently the magnetic domain structure in each ferromagnetic electrode. The combination of this powerful imaging technique with micromagnetic simulations allows us to evidence that a 360° domain wall can be stabilized in the NiFe soft layer. In this letter, we discuss the origin and the formation conditions of those 360° domain walls evidenced experimentally and numerically. © 2008 American Institute of Physics. DOI: 10.1063/1.2838455 Most studies concerning the micromagnetic properties JEOL 6500F scanning electron microscope. These structures of nanostructu