Review: X-ray scattering methods with synchrotron radiation
Resonant X-ray excitation (purple) core excites the oxygen atom within a H2O molecule. This causes ultrafast proton dynamics. The electronic ground state potential surface (bottom) and the bond dynamics is captured by distinct spectral features in resonant inelastic X-ray scattering (right).
© Martin Künsting /HZB
Synchrotron light sources provide brilliant light with a focus on the X-ray region and have enormously expanded the possibilities for characterising materials. In the Reviews of Modern Physics, an international team now gives an overview of elastic and inelastic X-ray scattering processes, explains the theoretical background and sheds light on what insights these methods provide in physics, chemistry as well as bio- and energy related themes.
"X-ray scattering can be used to investigate and resolve a wide variety of issues from the properties and excitations of fuctional solids, to homogeneous and heterogeneous chemical processes and reactions or even the proton pathway during the splitting of water," explains Prof. Dr. Alexander Föhlisch, who heads the Institute Methods and Instrumentation for Research with Synchrotron Radiation at HZB.
The article gives an overview of experimental and theoretical results in the field of resonant scattering of tunable soft and hard X-rays. The focus is on resonant inelastic X-ray scattering (RIXS) and resonant Auger scattering (RAS). In the review, the authors outline the most important achievements from the last two decades at Synchrotrons up to the latest advances in time-resolved studies with X-ray free-electron lasers.
- A new way to control the magnetic properties of rare earth elementsThe special properties of rare earth magnetic materials are due to the electrons in the 4f shell. Until now, the magnetic properties of 4f electrons were considered almost impossible to control. Now, a team from HZB, Freie Universität Berlin and other institutions has shown for the first time that laser pulses can influence 4f electrons- and thus change their magnetic properties. The discovery, which was made through experiments at EuXFEL and FLASH, opens up a new way to data storage with rare earth elements.
- BESSY II shows how solid-state batteries degradeSolid-state batteries have several advantages: they can store more energy and are safer than batteries with liquid electrolytes. However, they do not last as long and their capacity decreases with each charge cycle. But it doesn't have to stay that way: Researchers are already on the trail of the causes. In the journal ACS Energy Letters, a team from HZB and Justus-Liebig-Universität, Giessen, presents a new method for precisely monitoring electrochemical reactions during the operation of a solid-state battery using photoelectron spectroscopy at BESSY II. The results help to improve battery materials and design.
- HZB magazine lichtblick - the new issue is out!In his search for the perfect catalyst, HZB researcher Robert Seidel is now getting a tailwind – thanks to a ERC Consolidator Grant. In the cover story, we explain why the X-ray source BESSY II plays an important role for his research.