Fyzikální ústav Akademie věd ČR

Fast progress in miniaturization of electronic devices requires new approach not only in the technology, producing nanometric and subnanometric objects, but also in their characterization. EMCD – electron magnetic circular dichroism represents a new method, which uses the electron transmission microscope to determine the magnetic moments of atoms from which consists the object investigated. At present the resolution of EMCD is better than 10 nm and it has the potential of subnanometric resolution. The method allows separate determination of the spin and orbital parts of the magnetic moment. In our group a theoretical approach was developed, allowing to model and predict the experimental results. Of particular importance for the success of EMCD was modeling of the maps of the dichroic signal. The method is at present used and further developed by several groups in Austria, France, Sweden and USA.

• Detection of magnetic circular dichroism using a transmission electron microscope, P. Schattschneider, S. Rubino, C. Hubert, J. Rusz, J. Kuneš, P. Novák, E. Carlino, M. Fabrizioli, G. Panaccione, G. Rossi, Nature 441, 486 (2006).
• Sum-rules for electron energy-loss near-edge spectra, J. Rusz, O. Eriksson, P. Novák, P. Oppeneer, Phys. Rev. B 76, 060408(R) (2007).

Map of the dichroic signal for L3 (upper panel) and L2 (lower panel) edge of iron in magnetite.