Advanced Characterisation Methods (ACM)

(apl Prof. Dr.-Ing. Jan Frenzel, Dr. rer. nat. Christoph Somsen, Prof. Dr. Tong Li)

To start off with, the lecture reviews important aspects of the atomic configurations in amorphous and crystalline solids. It then considers the interaction of electrons with solids, discussing electron beams and highlighting the significance of secondary electrons, back-scattered electrons, elastically and inelastically scattered electrons and the origin of characteristic X-rays that are used for chemical analysis in electron microscopy. The physical origin of image contrasts in the scanning and the transmission electron microscope are discussed. Special emphasis is placed on the formation of Kikuchi line diffraction patterns. In scanning electron microscopy, Kikuchi lines are used for all orientation imaging techniques (OIM /EBSD) by which we can determine the orientation of grains and measure textures. In the case of transmission electron microscopy, Kikuchi line diffraction patterns are used as crystallographic maps that enable orienting single crystals. It will be explained how two beam diffraction contrasts can be obtained, and a brief introduction to stereographic 3D methods in scanning and transmission electron microscopy will be given. Furthermore, an introduction to atom probe tomography (APT) is given. and it will be demonstrated how APT can be correlated with EBSD and TEM to provide complementary information on microstructure.

The lecture is held in the summer semester on Fridays (3:00 to 6:00 p.m).

Lecture Announcement SS 2023

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