A climate-neutral energy supply requires a wide variety of materials for energy conversion processes, for example catalyti­cally active materials and new electrodes for batteries. Many of these materials have nano­structures that increase their func­tionality. When investigating these samples, spectro­scopic measurements to detect the chemical properties are ideally combined with X-ray imaging with high spatial resolution at the nanoscale. However, since key elements in these materials, such as molybdenum, silicon or sulphur, react pre­dominantly to X-rays in the tender photon energy range, there has been a major problem until now.

This is because in this “tender” energy range between soft and hard X-rays, conven­tional X-ray optics from plane grating or crystal mono­chromators deliver only very low efficiencies. A team from HZB in Berlin has now solved this problem: “We have developed novel mono­chromator optics. These optics are based on an adapted, multilayer-coated sawtooth grating with a plane mirror,” says Frank Siewert from the Optics and Beamlines Department. The new mono­chromator concept increases the photon flux in the tender X-ray range by a factor of 100 and thus enables highly sensitive spectro­microscopic measurements with high resolutions for the first time.

“Within a short time we were able to collect data from NEXAFS spectro­microscopy on the nanoscale. We have demons­trated this on cata­lytically active nanoparticles and modern microchip structures,” says Stephan Werner. “The new development now enables experiments that would otherwise have required months of data collection,” he emphasizes. “This mono­chromator will become the method of choice for imaging in this X-ray energy range, not only at synchro­trons worldwide, but also at free-electron lasers and laboratory sources,” says Gerd Schneider, who heads the X-ray Microscopy Department at HZB. He expects enormous effects on many areas of materials research: Studies in the tender X-ray range could signi­ficantly advance the development of energy materials and thus contribute to climate-neutral solutions for elec­tricity and energy supply. (Source: HZB)

Reference: S. Werner et al.: Spectromicroscopy of Nanoscale Materials in the Tender X-Ray Regime Enabled by a High Efficient Multilayer-Based Grating Monochromator, Small Meth., online 29 November 2022; DOI: 10.1002/smtd.202201382

Link: X-Ray Microscopy, Helmholtz-Zentrum Berlin für Materialien und Energie HZB, Berlin, Germany