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Vorträge und Posterpräsentationen (ohne Tagungsband-Eintrag):

P. Schattschneider, C. Hébert, St. Rubino, M. Stöger-Pollach, F. Houdellier, B. Warot-Fonrose, V. Serin, J. Rusz, P. Novák:
"Approaching 10 nm Resolution with Energy Loss Magnetic Chiral Dichroism (EMCD)";
Vortrag: EUROMAT 2007, Nürnberg, Germany; 10.09.2007 - 13.09.2007.



Kurzfassung englisch:
Approaching 10 nm Resolution with Energy Loss Magnetic Chiral Dichroism (EMCD)

P. Schattschneider (Sp), C. Hébert, S. Rubino, Vienna University of Technology, Wien (Austria); M. Stöger-Pollach, Vienna University of Technology (Austria); F. Houdellier, B. Warot-Fonrose, V. Serin, CEMES CNRS, Toulouse (France); J. Rusz, P. Novak, Academy of Science, Prague (Czech Republic)

X-ray magnetic circular dichroism (XMCD) was predicted 1975 and first observed in X-ray absorption spectra of the Fe K edge by Schütz et al [PRL 58 (1987) 737].
Nowadays, important information on orbital and spin magnetization, magnetic ordering and electronic correlation in a variety of ferro- and ferrimagnetic compounds is deduced from XMCD with the aid of modern synchrotrons.
The similarities between X-ray Absorption Near Edge Structures (XANES) and Energy Loss Near Edge Structures (ELNES) observable in the electron microscope have long been recognised [A. P. Hitchcock, Jpn. J. Appl. Phys. 32 (1993) 176]. However, the observation of circular dichroism in the TEM was thought to be impossible with existing technology because spin polarized electron ourcess of sufficient intensity were not available.
It was discovered recently that a spin polarized probe is not necessary. The chiral transitions that give rise to the XMCD effect have their counterpart in the Mixed Dynamic Form Factor (MDFF) for inelastic electron scattering. Since this quantity can be measured in the TEM under particular scattering conditions we predicted in 2003 that the counterpart of XMCD - called Energy-Loss Magnetic Chiral Dichroism (EMCD) - should be possible in the electron microscope. The effect was experimentally verified recently [P. Schattschneider et al., Nature 441 (2006) 486].
Here we present new results based on optimized signal detection showing that with EMCD atom- specific circular magnetic dichroism can be observed with a spatial resolution of better than 20 nm in a TEM equipped with an energy filter. With Cs correctors the resolution can be pushed down to the 10 nm range, thus surpassing the present detection limit of XMCD in a synchrotron.
In combination with other analytical tools available in the TEM this novel technique is of considerable interest for nanomagnetism and spintronics.


Elektronische Version der Publikation:
http://www.euromat2007.fems.org


Erstellt aus der Publikationsdatenbank der Technischen Universität Wien.