New monochromator optics for tender X-rays

Schematic drawing of the novel monochromator concept at the U41-PGM1 beamline at BESSY-II based on a multilayer coated blazed plane grating and mirror to improve the photon flux in the tender X-ray photon energy range (1.5 – 5.0 keV). The inset shows a TEM image of the cross-section of the Cr/C multilayer blazed grating structures. For better visualization of the grating period, the image was horizontally compressed 10 fold.

Schematic drawing of the novel monochromator concept at the U41-PGM1 beamline at BESSY-II based on a multilayer coated blazed plane grating and mirror to improve the photon flux in the tender X-ray photon energy range (1.5 – 5.0 keV). The inset shows a TEM image of the cross-section of the Cr/C multilayer blazed grating structures. For better visualization of the grating period, the image was horizontally compressed 10 fold. © HZB / Small Methods 2022

X-ray microscopy images of a 400 nm thick lamella cut out of a modern microchip device. The individual images were taken from a microspectrocopic energy series at the Si-K absorption edge. The NEXAFS spectra were extracted from the acquired energy series for SiCN and OSG materials. The corresponding energy peaks are related to the dominating Si-C bonds for SiCN and the dominating Si-O bonds for OSG dielectrics.</p> <p>&nbsp;

X-ray microscopy images of a 400 nm thick lamella cut out of a modern microchip device. The individual images were taken from a microspectrocopic energy series at the Si-K absorption edge. The NEXAFS spectra were extracted from the acquired energy series for SiCN and OSG materials. The corresponding energy peaks are related to the dominating Si-C bonds for SiCN and the dominating Si-O bonds for OSG dielectrics.

  © HZB / Small Methods 2022

Until now, it has been extremely tedious to perform measurements with high sensitivity and high spatial resolution using X-ray light in the tender energy range of 1.5 - 5.0 keV. Yet this X-ray light is ideal for investigating energy materials such as batteries or catalysts, but also biological systems. A team from HZB has now solved this problem: The newly developed monochromator optics increase the photon flux in the tender energy range by a factor of 100 and thus enable highly precise measurements of nanostructured systems. The method was successfully tested for the first time on catalytically active nanoparticles and microchips.

 

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 so-called 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 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 HZB 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, first author of the publication. "The new development now enables experiments that would otherwise have required months of data collection," Werner emphasises.

"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.

arö


You might also be interested in

  • BESSY II: How pulsed charging enhances the service time of batteries
    Science Highlight
    08.04.2024
    BESSY II: How pulsed charging enhances the service time of batteries
    An improved charging protocol might help lithium-ion batteries to last much longer. Charging with a high-frequency pulsed current reduces ageing effects, an international team demonstrated. The study was led by Philipp Adelhelm (HZB and Humboldt University) in collaboration with teams from the Technical University of Berlin and Aalborg University in Denmark. Experiments at the X-ray source BESSY II were particularly revealing.
  • Fuel Cells: Oxidation processes of phosphoric acid revealed by tender X-rays
    Science Highlight
    03.04.2024
    Fuel Cells: Oxidation processes of phosphoric acid revealed by tender X-rays
    The interactions between phosphoric acid and the platinum catalyst in high-temperature PEM fuel cells are more complex than previously assumed. Experiments at BESSY II with tender X-rays have decoded the multiple oxidation processes at the platinum-electrolyte interface. The results indicate that variations in humidity can influence some of these processes in order to increase the lifetime and efficiency of fuel cells. 
  • Best Innovator Award 2023 for Artem Musiienko
    News
    22.03.2024
    Best Innovator Award 2023 for Artem Musiienko
    Dr. Artem Musiienko has been awarded a special prize for his groundbreaking new method for characterising semiconductors. At the recent annual conference of the Marie Curie Alumni Association (MCAA) in Milan, Italy, he received the MCAA Award for the best innovation. Since 2023, Musiienko has been carrying out his research project with a postdoctoral fellowship from the Marie Sklodowska Curie Actions in Antonio Abate's department, Novel Materials and Interfaces for Photovoltaic Solar Cells (SE-AMIP).