HZB contributions to special edition on Ultrafast Dynamics with X-ray Methods
At the end of his contribution, Phillippe Wernet makes a great arch from the past (Opticae Thesaurus, 1572) of research with light to the future. © Wikimedia cc
In this theme issue leading researchers discuss
recent work on the ultrafast electronic and structural
dynamics of matter using a new generation of short
duration X-ray photon sources. © Royal Society
In the new special issue of the "Philosophical Transactions of the Royal Society of London", internationally renowned experts report on new developments in X-ray sources and ultrafast time-resolved experiments. HZB physicists have also been invited to contribute.
Almost 350 years after Isaac Newton's ground-breaking paper "Theory of Light and Colors (1671)", the world's oldest scientific journal “Philosophical Transactions” is now once again dedicated to light. The special issue on “Ultrafast Dynamics with X-ray Methods” is aimed at researchers who want to investigate biological, chemical or physical processes and obtain an overview of new developments in light sources and the methods available there. Dynamic processes in materials can be analyzed with high resolution and short pulses at X-ray light sources using ultrafast methods.
Femtoslicing and BESSY VSR
The special issue provides a comprehensive overview of current advances in the generation of ultra-short X-ray pulses by light sources such as Free Electron Lasers (FELs), High Harmonic Generation (HHG) laser sources and synchrotron radiation sources. An article in collaboration with Dr. Karsten Holldack, HZB, presents FEls and Laser sources but also classifies storage ring based methods such as “Femtoslicing” and BESSY VSR. These methods combine highly brilliant synchrotron light with a special time structure and thus allow to address unique experimental questions that cannot be answered at other sources. This complements and expands the portfolio of accelerator-based sources.
Ultra fast spectroscopy for photochemistry
An important contribution is dedicated to photochemistry, an area that focuses on processes such as photosynthesis, the dynamics of which are still largely unexplored. Using ultra-fast spectroscopy at FELs, HHG sources or at the synchrotron with BESSY VSR, methods are now available to measure in detail, for example, excitations of metallo-proteins and the subsequent reactions ; such experiments provide data that are indispensable, for example, for understanding photocatalysis of solar fuels. This article was written by Prof. Dr. Philippe Wernet, formerly a senior scientist at the HZB, and now a professor at Uppsala University, Sweden.
To the publications:
Measurement of ultrafast electronic and structural dynamics with X-rays; J. P. Marangos (ed.)
doi: 10.1098/rsta/377/2145
Recent Advances in Ultrafast X-ray Sources; Robert Schoenlein, Thomas Elsaesser, Karsten Holldack, Zhirong Huang, Henry Kapteyn, Margaret Murnane, Michael Woerner
doi: 10.1098/rsta.2018.0384
Chemical interactions and dynamics with femtosecond X-ray spectroscopy and the role of X-ray free-electron lasers; Philippe Wernet
doi: 10.1098/rsta.2017.0464
- Battery research with the HZB X-ray microscopeNew cathode materials are being developed to further increase the capacity of lithium batteries. Multilayer lithium-rich transition metal oxides (LRTMOs) offer particularly high energy density. However, their capacity decreases with each charging cycle due to structural and chemical changes. Using X-ray methods at BESSY II, teams from several Chinese research institutions have now investigated these changes for the first time with highest precision: at the unique X-ray microscope, they were able to observe morphological and structural developments on the nanometre scale and also clarify chemical changes.
- BESSY II: New procedure for better thermoplasticsBio-based thermoplastics are produced from renewable organic materials and can be recycled after use. Their resilience can be improved by blending bio-based thermoplastics with other thermoplastics. However, the interface between the materials in these blends sometimes requires enhancement to achieve optimal properties. A team from the Eindhoven University of Technology in the Netherlands has now investigated at BESSY II how a new process enables thermoplastic blends with a high interfacial strength to be made from two base materials: Images taken at the new nano station of the IRIS beamline showed that nanocrystalline layers form during the process, which increase material performance.
- Hydrogen: Breakthrough in alkaline membrane electrolysersA team from the Technical University of Berlin, HZB, IMTEK (University of Freiburg) and Siemens Energy has developed a highly efficient alkaline membrane electrolyser that approaches the performance of established PEM electrolysers. What makes this achievement remarkable is the use of inexpensive nickel compounds for the anode catalyst, replacing costly and rare iridium. At BESSY II, the team was able to elucidate the catalytic processes in detail using operando measurements, and a theory team (USA, Singapore) provided a consistent molecular description. In Freiburg, prototype cells were built using a new coating process and tested in operation. The results have been published in the prestigious journal Nature Catalysis.