[Back]

P. Schattschneider, J. Verbeeck, A.L. Hamon:
"Real space maps of atomic transitions";
Ultramicroscopy, 109 (2009), 781 - 787.

Considering the rapid technical development of transmission electron microscopes, we investigate the possibility to map electronic transitions in real space on the atomic scale. To this purpose, we analyse the information carried by the scatterer's initial and final state wave functions and the role of the different atomic transition channels for the inelastic scattering cross section. It is shown that the change in the magnetic quantum number in the transition can be mapped. Two experimental set-ups are proposed, one blocking half the diffraction plane, the other one using a cylinder lens for imaging. Both methods break the conventional circular symmetry in the electron microscope making it possible to detect the handedness of electronic transitions as an asymmetry in the image intensity. This finding is of important for atomic resolution energy-loss magnetic chiral dichroism (EMCD), allowing to obtain the magnetic moments of single atoms.

Electron energy loss spectrometry; Transmission electron microscopy; Circular dichroism; Coherence

http://dx.doi.org/10.1016/j.ultramic.2009.01.016

http://dx.doi.org/10.1016/j.ultramic.2009.01.016