Advanced Electron Microscopy in Materials Research

The research unit advanced electron microcopy in materials research focuses on structural, compositional and functional characterization providing a direct correlation between synthesis/processing and properties/functionality in materials research.
Electron Microscopy Group 2024Yuting Dai, KIT
High-end structural and compositional characterization is one of the essential requirements for advanced materials development; the experimental basis for a systematic understanding of materials and modelling. Electron microscopy is one of the most versatile and powerful tools to provide this basis by quantitative characterization of the atomic, nanometer and micron scale structure and composition. Moreover, in-situ experiments provide a direct correlation between structural changes, materials properties and functional behavior.
In addition to using state-of-the-art electron microscopy techniques for materials characterization, we develop microscopy techniques to provide answers to specific research problems in materials and physical sciences.

News & Publications

Ziming Ding PhD DefenseZiming Ding
Congratulations to the successful PhD defense to Dr. Ziming Ding

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!

Tor zur UnterweltMatthias Mail
Tor zur Unterwelt

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.

Group picture participants Hector seminarRene Kahlmeyer
HECTOR Seminar Bionics

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.

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Quadupolar strain field at a shear band in a metallic glasSangjun Kang
Pushing electron microscopy to directly image quadrupolar strain fields at shear bands in metallic glasses

4-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.

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Lithiated HEO - Orientation Mapping - Nature 2022Kai Wang
Understanding cation synergy in a CCO anode in lithium in battereies

This 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.

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Method Development

We are optimizing and developing new microscopy methods to address emerging structural and functional questions.
In-situ TEM Atmosphere Holder Protochips Inc.
In-situ TEM

Heating, biasing, electro-chemistry, gas environment, mechanical deformation

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4D-STEM Xiaoke Mu, KIT
4D-STEM

Automated crystal orientaton mapping

Pair distrubution function mapping

Differential phase contrast

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Electron Tomography in Catalysis Wu Wang, KIT
Electron Tomography

Quantitative 3D nanoscale and microscale analysis

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Materials Research

We are applying advanced electron microscopy techniques such as (S)TEM, EELS, EDX, NBED, tomography and FIB to characterize a variety of materials for different application areas.
Battery Interfaces Christian Kübel, KIT
Batteries

Understanding nanostructure and functional properties of electrodes and solid electrolytes

Role of interface for battery performance

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Catalysis Christian Kübel, KIT
Catalysis

Atomic structure of the active catalytic center

Metal-Support Interaction

Nano and micro scale morphology

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Magnetic Materials Di Wang & Saleh Gorji, KIT
Magnetic Materials

Atomic structure and chemistry

Magnetic domain structure

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Metallic Glasses Teaser Xiaoke Mu, KIT
Metallic Glasses

Bulk metallic & nano glasses

Local structural & compositional analysis

Shear band structure

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Nanocrystalline Metals Christian Kübel, KIT
Nanocrystalline Metals

Quantitative structural description of nanocrystalline metals

Mechanical deformation

Thermal evolution

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Compositionally complex alloys Lakshmi Mantha, KIT
Compositionally Complex Alloys

Nano- & Microstructure Characterization

In-situ heating and in-situ mechanical evolution

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High Entropy Oxides Kai Wang, KIT
High Entropy Oxides

Atomic structure & chemistry

Electron structure

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Multiferroic Thin Films Di Wang & Saleh Gorji, KIT
Multiferroic Thin Films

Atomic structure and chemistry at interfaces

Ferroelectric & magnetic structure

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Self-Assembly of Janus Type Clusters Wei Wang, Nankai University
Self-Assembled Nanomaterials

Low-dose TEM & electron tomography characterization of complex hybrid materials.

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4D-STEM P3HT/PCBM Microscopy
Organic Photovoltaics