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METSA-SET-DIA: Improving Scanning Electron Tomography Experiments Using Direct Electron Detectors and Innovative Algorithms
Responsible: Pascale Bayle-Guillemaud, IRIG/CEA Grenoble
Keywords: Tomography, scanning electron microscopy, 3D structure, three-dimensional chemical characterization, Energy Electron Loss Spectroscopy (EELS), ptychography, direct electron detection camera, nanoscale, atomic scale
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DIADEM’s mission is to accelerate the development of new materials in France, by combining modeling, digital simulation, methodologies associated with artificial intelligence (AI), synthesis/screening technologies and high-throughput characterization in an integrated manner. METSA-SET-DIA contributes to the achievement of this mission by optimizing and developing three Tomography techniques in a transmission electron microscope in Scanning mode (Scanning Electron Tomography: SET), so that they are faster, more efficient and more efficient. automatic.
The three SETs chosen are complementary and have several points in common: EELS-SET for three-dimensional (3D) chemical characterization at the nanoscale (EELS: Energy Electron Loss Spectroscopy), Nano-SET and Ptycho-SET for structural characterization respectively at the nanometric and atomic scale. METSA-SET-DIA will rely on:
- the equipment and know-how present either on the NanoCharacterization Platform (PFNC) of Minatec at CEA-Grenoble, or on those of the NEEL institute (NEEL) in Grenoble,
- new equipment purchased, either within the framework of METSA-SET-DIA, or outside DIADEM (installation of a new low-voltage microscope, early 2023 at CEA, and installation of a new microscope during 2022 at NEEL).
Two of the proposed SET techniques (EELS-SET and Nano-SET) are already well mastered at the PFNC and the METSA-SET-DIA project will make it possible to accelerate and automate them:
- by using a new type of direct electron detection camera (DeD: Direct Electron Detector), without noise and sensitive to a single electron and with temporal resolution,
- by improving digital techniques for reconstructing 3D images using the concepts of Deep Learning (DL) and parsimony,
- by optimizing the management and digital processing of large experimental data (use of clusters or graphics cards).
The third SET, ptycho-SET, is completely new but it is in fact an association of tomography and 2D-ptychography techniques which will use very similar methods (same detector, same scanning, digital processing techniques, etc.) to both other SETs. This ‘tomo-ptycho’ association has already been demonstrated in the case of X-rays but with a resolution of the order of a nanometer whereas in the case of METSA-SET-DIA, and therefore electrons, a resolution of atomic scale of a few picometers should be obtained. Having rapid and semi-automatic characterization tools to determine the structure and chemistry of materials should greatly help in the design and development of new materials with improved properties. As a demonstration, the techniques developed will of course be applied to a selection of materials developed within the framework of DIADEM.
By relying on the tools and infrastructures implemented in the various DIADEM platforms, the developments carried out in METSA-SET-DIA will be accelerated and optimized and the know-how and knowledge acquired can be quickly disseminated on a large scale. national thanks to exchanges with the French research infrastructure METSA (Transmission Electron Microscopy and Atomic Probe).