Advanced Electron Microscopy in Materials Research
Ziming Ding successfully defended her PhD thesis on 'In Situ Transmission Electron Microscopy Investigation of All Solid-state Sodium Batteries' in the Materials Science Department at TU Darmstadt on January 30th 2024. Congratulations Ziming!
The picture 'Tor zur Unterwelt' by Matthis Mail, a colored SEM image of a Plasma-FIB prepared hole in a polymer sample, won the first price in the picture contest at the Nano-BW symposium 2023 in Bad Herrenalb. Congratulations Matthias.
18 pupils of the Bismark Gymnasium in Karlsruhe and the HECTOR seminar Baden-Württemberg successfully completed the module "Bionik - Verständnis durch Elektronenmikroskopie entwickeln", spending 11 weeks using SEM and optical microscopy to image surface structures in biological systems and their technical counterparts to understand how the structure gives rise to different properties such as the Lotus effect, light harvesting, structural colors, Gecko effect, Salvinia effect and the mechanical stability of diatoms. The results were presented in a seminar on July 6th and at the HECTOR Modulfest on July 8th.
Link_more4-dimensional-STEM (4D-STEM) analysis of amorphous materials has been pushed to new limits and applied to map and directly correlate the local strain and the atomic structure at the nanometer scale in deformed metallic glasses. Residual strain fields are observed with quadrupolar symmetry concentrated at dilated Eshelby inclusions. The strain fields percolate in a vortex-like manner building up the shear band. This provides a new understanding of the formation of shear bands in metallic glass. Details have been published in Advanced Materials 2023.
Link_moreThis work unveils the multi-cations synergy of the HEO Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O at atomic and nanoscale during electrochemical reaction and explains the ‘cocktail effect’. The more electronegative elements form an electrochemically inert 3-dimensional metallic nano-network enabling electron transport. The electrochemical inactive cation stabilizes an oxide nanophase, which is semi-coherent with the metallic phase and accommodates Li+ ions. This self-assembled nanostructure enables stable cycling of micron-sized particles, which bypasses the need for nanoscale premodification required for conventional metal oxides in battery applications. This demonstrates elemental diversity is the key for optimizing multi-cation electrode materials. Details have been published at Nature Communications 2023.
Link_moreMethod Development
Heating, biasing, electro-chemistry, gas environment, mechanical deformation
linkAutomated crystal orientaton mapping
Pair distrubution function mapping
Differential phase contrast
linkQuantitative 3D nanoscale and microscale analysis
linkMaterials Research
Understanding nanostructure and functional properties of electrodes and solid electrolytes
Role of interface for battery performance
linkAtomic structure of the active catalytic center
Metal-Support Interaction
Nano and micro scale morphology
linkQuantitative structural description of nanocrystalline metals
Mechanical deformation
Thermal evolution
linkLow-dose TEM & electron tomography characterization of complex hybrid materials.
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