High-sensitivity nanoscale chemical imaging with hard x-ray nano-XANES

X-rays with excellent penetration power and high chemical sensitivity are suited to understand heterogeneous materials. In a new report on Science Advances, A. Pattammattel, and a team of scientists at the National Synchrotron Light Source in New York, U.S., described nanoscale chemical speciation by combining scanning nanoprobe and fluorescence-yield X-ray absorption near-edge structure—known as nano-XANES. The team showed the resolving power of nano-XANES by mapping states of iron of a reference sample composed of stainless steel and hematite nanoparticles using 50-nanometer scanning steps. Using nano-XANES, the team also studied the trace secondary phases of lithium iron phosphate (LFP) particles and noted the individual iron(Fe)-phosphide nanoparticles within the pristine lithium iron phosphate, while partially delithiated particles showed Fe-phosphide nanonetworks. This work on nano-XANES highlight the contradictory reports on iron-phosphide morphology within the existing literature and will bridge the capability gap of spectromicroscopy methods to provide exciting research opportunities.