Services for Ulm University
The group of electron microscopy of material science (EMMS) carries out service investigations related to material science and physics for members of the university.
Electron microscopy is preferentially used for investigations of structures smaller than the wavelength of visible light. Electron microscopy surpasses the limits of optical microscopes. This usually means investigations of object sizes in the range of micrometers to nanometers .
Two basic kinds of electron microscopes are applied: scanning electron microscopes (SEM) for investigations of the surface, and transmission electron microscopes (TEM) for investigations of the volume. SEM offers a resolution down to 1 nm, while TEM is able to obtain atomic resolutions of less than 0.1 nm. This high resolution requires very, very thin samples (typical thickness <50 nm). The preparation of such thin samples is a necessary step prior to the TEM investigation. A wide range of methods is available for TEM sample preparation.
Analytical techniques (energy dispersive X-ray spectroscopy (EDX), electron energy loss spectroscopy (EELS)) enable the determination of chemical composition of the sample on a (sub)-nanometer scale.
A unique feature of a TEM is the possibility to obtain image (real space), spectroscopic and diffraction (reciprocal space) information at the same time a high spatial and high energy resolution.
Furthermore, nanostructuring of samples can be carried out using a combined FIB/SEM. This setup uses a focussed gallium-ion beam (FIB) to structure (etching, cutting and deposition) while imaging at the same time of the sample is possible using the SEM. A FIB/SEM may also be used for target preparation of thin TEM lamellae.
Here you get an overview about some of our examples within the service research methods and techniques.