A method for extraction of crystallography-related information from a data cube of very-low-energy electron micrographs

Scanning Low Energy Electron Microscopy (SLEEM) is an imaging technique which uses low energy electrons while providing a very good image resolution. Reflectivity of very slow electrons in the range 0–30 eV can be correlated with the electronic structure of the material, aiming at the determination of the local crystallographic orientation. Since SLEEM is a 2D imaging method, a suitable algorithm is needed to pre-process the image data depending on the beam energy as the third dimension. The crucial task is to detect grain boundaries in polycrystals and evaluate the image signal in connection to the energy of electron impact. Recent algorithms performing the task for the traditional EBSD method are not suitable as they do not address the side-effects of the SLEEM technique. We propose a method that detects the grain boundaries while correcting for image distortion caused by the variation of cathode lens strength, and for several other issues.