HZB and Freie Universität Berlin establish the joint research group “X-Ray Microscopy” for studying complex cellular processes
In May this year, the joint research group “X-Ray Microscopy” was launched, combining the expertise of teams led by Prof. Dr. Gerd Schneider (Helmholtz-Zentrum Berlin) and Prof. Dr. Helge Ewers (Freie Universität Berlin). While Ewers’ group contributes its experience in the field of optical microscopy and biological research, the HZB workgroup is responsible for X-ray microscopy at the synchrotron source BESSY II. The two methods help researchers to gain a detailed insight into the processes taking place inside cells.
We are very pleased about the new cooperation with Prof. Ewers’ workgroup. It gives our own activities in this field a much stronger connection to the biological research being done at the university,” says Prof. Dr. Gerd Schneider. The core duties of his department at HZB include making advancements to the x-ray microscopes and lenses at the synchrotron source BESSY II. The active exchange between the new cooperation partners will give a new boost to method development, says Schneider. Prof. Dr. Helge Ewers is also excited about the future-oriented cooperation: “X-ray microscopy opens up entirely new possibilities for us in the research of intracellular processes.”
The joint research group is all about the complementary use of optical and X-ray microscopy. Optical microscopy and super-resolution methods are excellent for locating proteins marked with dye molecules in tissue samples. X-ray microscopy, in turn, allows correlative imaging of the distribution of proteins, viruses or nanoparticles over a relatively large section in high-resolution and three-dimensions. The two microscopy methods thus deliver a comprehensive picture of the intracellular structures and processes.
After a successful upgrade, the X-ray microscope TXM at the synchrotron source BESSY II is now available again to users. Aside from biological studies, which can now be conducted with the combined expertise in the joint research group, the X-ray microscope is used above all for exploring various questions of materials and energy research.
- BESSY II: New sample environment allows glimpse into thermocatalytic processesA novel measurement cell allows, for the first time, soft and hard X-ray investigations under high pressures of up to 20 bar and temperatures of up to 400°C. This provides new insights into thermocatalytic processes, such as the Fischer-Tropsch synthesis for producing synthetic fuels. The development of the measurement cell is considered a significant achievement within the Care-O-Sene project.
- Magnetic imaging: Micro-flowers increase the local magnetic fieldMaterials with magnetic nanostructures have many potential applications such as in spintronics. To explore such materials, nanoscale magnetic-sensitive imaging techniques are very useful, but up to now only weak magnetic fields could be applied during the imaging process. Now an international collaboration led by Dr. Sergio Valencia, HZB, has developed an approach that overcomes this limitation. The team designed tiny magnetic flux concentrators (MFCs), into which the sample is placed. The geometry of the MFCs resembles a flower with a number of petals which focus the applied magnetic field into its center. This greatly expands the magnetic field range available during imaging, and so the range of magnetic systems that can be investigated. The micro-flowers, enhancing magnetic fields locally, can find application in different nanometric magnetic microscopy techniques.
- Disorder creates new properties in compound semiconductorsAn international research team has demonstrated that the intrinsic disorder of the compound semiconductor CuInSnS₄ can be exploited to influence its optical properties. While the atomic vibrations also sense the local disorder, their response is averaged over many different local environments and therefore appear isotropic, as expected for a cubic crystal. In contrast, the optical excitations, known as excitons, are much more sensitive to the local arrangement of atoms. Surprisingly, they show a direction-dependent optical response even though the average crystal structure is cubic. These findings shed new light on the relationship between disorder and material properties, opening up new options for targeted 'disorder engineering' in optoelectronic and photocatalytic devices.