Breakthrough in X-Ray Nanospectroscopy

This picture schematically shows the studied titanium dioxide rods<br />illuminated by X-rays of various photon energies through a capillary<br />condenser. A high-resolution lens &ndash; not shown here &ndash; then forms<br />an image of the objects.<br />Source: HZB

This picture schematically shows the studied titanium dioxide rods
illuminated by X-rays of various photon energies through a capillary
condenser. A high-resolution lens – not shown here – then forms
an image of the objects.
Source: HZB

HZB researchers achieve X-ray spectroscopy at nanoscale spatial resolution

Researchers at Helmholtz Zentrum Berlin (HZB) have developed a new microscope for high spatial resolution X-ray spectroscopic studies. While conventional X-ray spectroscopy has so far fallen short of resolving single nanoparticles, the X-ray microscope at HZB’s synchrotron source BESSY II succeeds by using high-brilliancy X-rays.

Indeed, one of the essential reasons for studying nanoparticles or nanostructures is to determine their individual sizes and electronic properties. To attain the necessary spatial resolution, down to the nanoscale, the structures have to be illuminated with X-rays at high spectral resolution and imaged onto a detector using an X-ray lens. Dr. Peter Guttmann and the microscopy team of PD Dr. Gerd Schneider at the HZB Institute for Soft Matter and Functional Materials have published the new method in Nature Photonics:

  • Flash: http://content.yudu.com/A1vo3s/Nanotimes01-2012/
  • Plain text version live at: http://content.yudu.com/A1vo3s/Nanotimes01-2012/resources/plainText.htm
  • PDF (97 pages, 16Mb): http://www.nano-times.com/files/nanotimes_12_01.pdf

There is great interest in the electronic properties of nanostructures, which can be functionalized in all kinds of ways, for example as active materials with a large surface area and small volume. Conceivable uses are in lithium-ion batteries, for example, or in photocatalysis to produce hydrogen as an energy carrier, or in solar cells. The HZB microscope is a new and attractive tool for materials sciences, and for energy research in particular.

This method can take pictures of nanoparticles inside object fields of up to 20 x 20 µm2 simultaneously with a CCD camera. An object field of this size holds many structures of interest. By recording image data in very small energy steps over a select energy range, the researchers obtain records of high-spatial-resolution images with spectral information. This provides a spectrum of each individual particle or portion of the nanostructure. These NEXAFS spectra, as they are called, reveal information about the electronic structure and ultimately the arrangement of the individual atoms within the nanoparticle. Unlike scanning X-ray microscopy, which measures sequentially the spectra of single nanoparticles with each picture, an image stack from the new method already contains the spectra of a large number of particles, meaning it already has statistical significance.

“An important advantage of our microscope is the time gain on top of the improved spectral resolution of 10,000,” says Dr. Peter Guttmann, physicist at HZB. “Unlike the scanning X-ray microscopes used so far for this, our microscope allow spectra to be recorded 100 times faster inside large object fields. We can use the HZB electron beam writer to produce advanced lenses that will improve our method from the current 25 nm to a spatial resolution of 10 nm.”

At the high spatial and spectral resolution of the microscope, the researchers cooperated with co-authors from Belgium, France and Slovenia to study the structure of specially built titanium dioxide nanorods. The nanorod studies they now present were done as a European cooperative as part of the COST action MP0901(NanoTP).

HS

  • Copy link

You might also be interested in

  • BESSY II: New procedure for better thermoplastics
    Science Highlight
    04.11.2024
    BESSY II: New procedure for better thermoplastics
    Bio-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 electrolysers
    Science Highlight
    28.10.2024
    Hydrogen: Breakthrough in alkaline membrane electrolysers
    A 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.
  • Alternating currents for alternative computing with magnets
    Science Highlight
    26.09.2024
    Alternating currents for alternative computing with magnets
    A new study conducted at the University of Vienna, the Max Planck Institute for Intelligent Systems in Stuttgart, and the Helmholtz Centers in Berlin and Dresden takes an important step in the challenge to miniaturize computing devices and to make them more energy-efficient. The work published in the renowned scientific journal Science Advances opens up new possibilities for creating reprogrammable magnonic circuits by exciting spin waves by alternating currents and redirecting these waves on demand. The experiments were carried out at the Maxymus beamline at BESSY II.