Gerd Schneider receives a professorship for "X-ray microscopy" at Humboldt-Universität zu Berlin
Prof. Dr. Gerd Schneider becomes a full professur for x-ray microscopy at the Humboldt University Berlin and is the head of the HZB group "Microscopy". © WISTA MANAGEMENT GmbH
On 29 April 2015, Gerd Schneider (HZB) accepted the call to a W2-S “X-ray microscopy” professorship at the Department of Physics of Humboldt-Universität zu Berlin. The professorship is associated with heading the workgroup “X-ray microscopy” at the Helmholtz-Zentrum Berlin für Materialien und Energie. With his group, the internationally recognised expert is developing new methods and applications for X-ray microscopy, which delivers crucial information for many scientific disciplines – from material and energy research to the life sciences.
The workgroup of Gerd Schneider operates one of the most advanced X-ray microscopes in the world, which allows spatial resolutions of down to ten nanometres using the “soft” X-ray light from BESSY II.
X-ray microscopy is an indispensable tool for studying materials
X-ray microscopy has decisive advantages over optical and electron microscopy: It allows researchers to observe objects in three dimensions, for example – and that at a very high resolution of 10 nanometres. “While researchers can only observe very thin samples of a maximum of about 0.1-µm thickness under the electron microscope, X-ray microscopy allows you to study entire cells of 10-µm thickness, for example. Compared to modern, super-resolution optical microscopy, which needs stain molecules inside cells to overcome the Abbé resolution limit, X-ray microscopy delivers a direct view to the cellular structures without any staining,” Prof. Gerd Schneider explains. Optical and X-ray microscopy therefore allow the study of whole cells, where correlative optical microscopy of individual cells can localise certain proteins whose distributions can be brought into a structural cellular context using X-ray microscopy.
Since every chemical element has specific X-ray absorption edges, X-ray microscopy can be used to determine the specific elements in the components of a sample. Even chemical bonding states can be clearly imaged using near-edge spectroscopy. Because the elements exhibit characteristic fluorescence under X-ray lights, one can also clearly determine the spatial distribution of extremely low concentrations of elements in a sample. In this way, X-ray microscopy delivers a comprehensive picture of each sample.
Developing high-precision lenses
Achieving the highest possible resolution in X-ray microscopy requires high-precision lenses to focus the X-ray beams. In addition to developing X-ray microscopes, Gerd Schneider’s workgroup has contributed greatly to the advancement of these lenses, known as Fresnel zone plates. Given such 3D X-ray lenses and modern synchrotron sources like BESSY II, great contributions can be made towards answering many scientific questions, from the fundamentals of structural biology to research into modern energy storage solutions.
- Synchrotron radiation sources: toolboxes for quantum technologiesSynchrotron radiation sources generate highly brilliant light pulses, ranging from infrared to hard X-rays, which can be used to gain deep insights into complex materials. An international team has now published an overview on synchrotron methods for the further development of quantum materials and technologies in the journal Advanced Functional Materials: Using concrete examples, they show how these unique tools can help to unlock the potential of quantum technologies such as quantum computing, overcome production barriers and pave the way for future breakthroughs.
- Peat as a sustainable precursor for fuel cell catalyst materialsIron-nitrogen-carbon catalysts have the potential to replace the more expensive platinum catalysts currently used in fuel cells. This is shown by a study conducted by researchers from the Helmholtz-Zentrum Berlin (HZB), Physikalisch-Technische Bundesanstalt (PTB) and universities in Tartu and Tallinn, Estonia. At BESSY II, the team observed the formation of complex microstructures within various samples. They then analysed which structural parameters were particularly important for fostering the preferred electrochemical reactions. The raw material for such catalysts is well decomposed peat.
- Helmholtz Investigator Group on magnonsDr Hebatalla Elnaggar is setting up a new Helmholtz Investigator Group at HZB. At BESSY II, the materials scientist will investigate so-called magnons in magnetic perovskite thin films. The aim is to lay the foundations for future terahertz magnon technology: magnonic devices operating in the terahertz range could process data using a fraction of the energy required by the most advanced semiconductor devices, and at speeds up to a thousand times faster.