Transmission Electron Microscopy (TEM) for advanced students
(Prof. Dr. Gerhard Dehm)
The lecture introduces the design and experimental possibilities of modern transmission electron microscopes (TEMs). This includes an introduction of the functionality of electron sources in use today. The lecture explains the operation of a conventional TEM, focusing on the imaging and diffraction operational modes. Then high modern analytical high resolution TEMs are discussed, often benefiting from a scanning mode (STEM mode) that allows the improvement of image quality and easier access to local chemical information. The fundamentals of elastic and inelastic interactions between the electrons of the incoming electron beam and matter as well as the resulting mechanism of image formation in conventional and high resolution analytical TEMs are discussed. The limiting effect of lens aberrations are outlined, and today’s possibilities of correcting the spherical aberration (Cs-corrector) are treated. The physical concept of the contrast transfer function and the resolution limits of modern TEM are further topics. The students learn to interpret TEM micrographs and to evaluate TEM diffraction patterns. The class is organized as a lecture block in the winter semester and will be announced.
Lecture Announcement:
TEM Fortgeschittene WS 2021_22.pdf