We are using state-of-the-art imaging, spectroscopy and diffraction based electron microscopy techniques, both in-situ and ex-situ, to understand materials and provide a link to simulations. When state-of-the-art techniques do not provide sufficient answers, we tackle research problems by dedicated method developments.
Analytical (S)TEM and diffraction techniques are in principle well established, but when it comes to characterizing beam sensitive materials, their structure and defects, especially under in-situ conditions, obtaining meaningful structural information to understand their performance is highly challenging. We are tackeling this using selected samples, dedicated prepration and low-dose techniques.
We are addressing structure, composition and morpology from the atomic scale to the micron scale, both in-situ and ex-situ, to better understand the active sites involved in catalytic reactions, their evolution over time as well as diffusion and flow properties of the overall catalyic system.
Advanced analytical TEM characterization is used to determine the crystal structure and elemental distribution at atomic resolution as well as electronic structure for each cation.
The interface structure and chemistry are characterized by HRTEM, HR-STEM and STEM-EDX/EELS spectrum imaging. In addition, the magnetic and ferroelectric domains can be imaged using 4D-STEM techniques.
Nanocrystalline metals exhibit a high volumetric fraction of grain boundaries and various defects dominating their structure and mechanical properties. We are using HR(S)TEM imaging and crystal orientation mapping in oder to understand their structure at the atomic and nanoscale and relate it to their mechanical properties in in-situ deformation experiments.
Nanostructured metallic glass–composites (i.e. nanoglasses), consisting of multiple amorphous phases at the nanoscale, exhibit not only significantly improved ductility compared to their monolithic BMG counterparts, but also with exceptional physical, e.g. magnetic, properties. The unique behavior of nanoglasses is speculated to be due to the nanoscale (structural/chemical) phase separation and related changes in atomic short-range order. A clear correlation of the properties with the multiphase glassy structure is an essential task to understand and rationalize their applications.
We are using a combination of advanced analytical (S)TEM techniques to characterize the atomic structure and chemistry. This information is correlated with the magnetic domain structure observed using Lorenz imaging as well as STEM-DPC. This characterization is also performed in-situ to follow magnetic transitions.
We are using various low-dose imaging, spectroscopy and tomography techniques to characterize the structure and morphology of self-assembled hybrid materials in 2D and 3D.