Transmission electron microscopy beyond the limits of imaging.

The main objective of this proposal is to push aberration corrected transmission electron microscopy (TEM) toward precise measurements of unknown structure parameters. Although the resolution of these state-of-the-art instruments has greatly been improved by optimizing the lens design, equally fundamental changes in the image processing and acquisition methods are required in order to have the instrument performing at the limits of its capabilities. Therefore, use will be made of statistical parameter estimation theory. The starting-point is the availability of a parametric model describing the expectations of the images. This is a physics-based model depending on the unknown structure parameters. It describes the interaction of the electrons with the object, the transfer in the microscope, and the detection. Next, the unknown parameters are estimated by fitting this model to the experimental images using a criterion of goodness of fit. Through a combination of available techniques in TEM, the focus in this project will be to determine atom positions with picometer precision for heavy as well as for light atoms, precise chemical composition analysis, and detection of single atoms. Finally, in order to study beam sensitive matter without radiation damage, the principles of statistical experimental design will be used to determine the minimally required electron dose in order to attain a pre-specified precision.

Keywords:ELECTRON MICROSCOPY (QUANTITATIVE), TRANSMISSION ELECTRON MICROSCOPY

Disciplines:Applied mathematics in specific fields, Astronomy and space sciences, Classical physics, Condensed matter physics and nanophysics, Materials physics, Mathematical physics, Quantum physics, Modelling, Biological system engineering, Signal processing

Project type:Collaboration project