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MM: Fachverband Metall- und Materialphysik

MM 14: Topical Session TEM IV

MM 14.2: Topical Talk

Tuesday, March 15, 2011, 11:30–12:00, IFW A

Quantification of instrumental properties in high-resolution transmission electron microscopy — •Juri Barthel and Andreas Thust — Institute for Solid State Research and Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

The precise characterization of the instrumental imaging properties in the form of aberration parameters constitutes an almost universal necessity in quantitative high-resolution transmission electron microscopy, and is underlying most hardware and software techniques established in this field. An effective and reproducible aberration control depends on two crucial aspects: First, an adequate aberration measurement technique is required, which must achieve a sufficient precision depending on the instrumental information limit. Second, an accordingly high optical stability of the microscope is needed, because the relevance of an aberration measurement ends with the lifetime of the measured optical state.

Both prerequisites, measurement precision and instrumental stability, are investigated in a quantitative way with respect to their achievable limits. Numerical procedures are presented for the automatic extraction of the two lower-order aberrations, defocus and 2-fold astigmatism, from single diffractograms of amorphous material [1]. The novel procedures achieve a precision of a nearly 1 Angstrom, which is sufficient to control the optical state and to assess its stability for successful sub- Angstrom microscopy.

[1] J. Barthel, A. Thust, Ultramicroscopy 111 (2010) 27 - 46.