Electron microscopy offers the possibility to characterise microscopic defect structures in crystals, and it is the only method available for this task.

The study of such processes and intermediate products in the reacting regions requires methods with high local sensitivity. For that the various methods of TEM are best suited.

Thin films serve as isolating, dielectric, magnetic or electronic components e.g. for integrated antennas and transmitters and radio frequency filters in mobile phones, or for semiconductor elements in integrated circuits of microelectronic products (computer).

amorphous (greek: without shape) inorganic solids, without any long range structural order are denoted as glasses. Even metals which have been rapidly cooled from the melt and contain chemical additions can be obtained as (metallic) glasses.

Synthesis and characterization of nanostructuctures are in the focus of our research. To the structures of interest belong two dimensional (thin films), one dimensional (nanowires or -rods) and „zero” dimensional objects such as nanocrystal

The contrast formation in high resolution TEM (HRTEM) can only be explained by the wave nature of electrons. In HRTEM a virtually planar electron wave transmits a thin specimen (thickness < 20 nm), in most cases a crystal. During transmission the incident electron wave is scattered (or diffracted in the case of a crystal) at the potentials of the atoms, and thereby the phase of the electron wave is changed. 

Amorphous solids and glasses are produced and studied in the "collaborative research centre SFB 408" at the university of Bonn. Such solids do not exhibit any long range structural order of the atoms. When irradiated by electrons, these materials produce diffuse scattering patterns in which the scattered intensity falls off with increasing scattering angle. 

Passing a thin specimen, primary electrons can loose energy when they collide with electrons from the atoms of the material. With an energy filter these inelastically scattered electrons can be dispersed as a function of their energy and then detected using either a linear diode array or a CCD camera. As the excited electron will take some kinetic energy with it (which the primary electron must supply) one gets ionization edges on top of an approximately exponentially decaying background, rather than discrete peaks in x-ray microanalysis.

Different from the diffraction of X-rays or neutrons, the interaction of electrons with matter is some orders of magnitude stronger. A resulting advantage of electron diffraction is that only small volumes are required for the investigation.