Sigray QUANTUMLEAP XAS
CHEMICAL SPECIATION AND ELECTRONIC STRUCTURE WITH X-RAY ABSORPTION SPECTROSCOPY
Sigray’s QuantumLeap™ brings the long-awaited power of X-ray absorption spectroscopy (XAS), a synchrotron technique for determining electronic structure of elements, to individual laboratories. With QuantumLeap, researchers will now be able to identify and quantify the chemical species of elements of interest for applications such as:
Catalysts: chemical states of oxides, nitrides, and carbides being explored as catalysts
Batteries/fuel cells/solar cells: oxidation state of transition metals (e.g. in lithium ion batteries) as a function of charge and discharge cycles
Nanoparticles and nanomaterials: structural analysis, coordination number, disorder, geometry, reactivity
What is XAS?
X-ray absorption spectroscopy (XAS) is a technique in which the x-ray energy is scanned in incremental steps near the specific absorption edge (binding energy) of an element of interest. At this energy, x-rays typically are absorbed by an electron that is then emitted from the atom. XAS is comprised of two regimes:
XANES and EXFAS
The near-edge XANES region contains features and shifts in the absorption peak values caused by the transition of core electrons to non-bound levels, and is sensitive to local atomic states such as oxidation states.
Extended fine structure (EXAFS) above the edge are formed by the wave-like nature of the emitted photoelectron, which
is scattered by surrounding atoms and forms oscillations from constructive and destructive interference that can
be then used to infer bond lengths and information on neighboring atoms.
- Unprecedented ability to analyse electronic (chemical) state of elements
- First laboratory micro-XANES system, providing spatial resolution down to 10 μm
- XANES mode for oxidation state analysis and bond covalency (down to 0.1 eV)
- EXAFS mode for coordination number, types of donors bound, and interatomic distances (<10 eV)