User research at BESSY II: Formation of a 2D meta-stable oxide in reactive environments
Illustration of a CuxOy structure formed on a AgCu alloy in oxidizing environments described in this work. (c) ACS Applied Materials & Interfaces. © (2020) ACS Publishing
The chemical behaviour of solid material surfaces is an important physical characteristic for applications of catalysis, chemical sensors, fuel cells and electrodes. A research team from the Max Planck Institute for Chemical Energy Conversion has now described an important phenomenon that can occur when metal alloys are exposed to reactive environments at the synchrotron source BESSY II.
In a recent work published in ACS Applied Materials & Interfaces, a researchers’ team led by Dr. Mark Greiner (Surface Structure Analysis, Department of Heterogeneous Reactions) demonstrates an important phenomenon that can occur when metal alloys face reactive environments. They can form meta-stable 2D oxides on their surfaces. Such oxides exhibit chemical and electronic properties that are different from their bulk counterparts. Due to their meta-stability, their existence is also difficult to predict.
This publication displays the results of a thorough investigation of one such oxide, confirming previous theoretical predictions of its existence, and helps to advance the understanding of the complexity of solid surfaces in reactive environments. The investigations were performed using in-situ photon electron spectroscopy at the ISISS beamline and the UE49-PGM beamline at BESSY II.
This investigation was a collaborative research effort between the Max Planck Institute for Chemical Energy Conversion, the Max-Planck-Institut für Eisenforschung, the Fritz Haber Institute of the Max Planck Society, the Helmholtz Zentrum Berlin and the Italian National Research Council Institute of Materials (CNR-IOM).
- 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.