NSLS-II Seminar

There is growing recognition in the materials community of the need to study disorder in materials at both the sub-nanometer and nanometer lengths scales with atomic resolution. The Pair-Distribution-Function (PDF) technique recovers structural information, in the form of a radial distribution of atom-atom distances without the assumptions of symmetry constraints that crystallographic approaches rely on. Information on both the local and intermediate range length scales is probed, and therefore PDF is an ideal match for probing atomic scale disorder. Recent advances in PDF measurements combining area detectors and high-energy X-rays have dramatically decreased measurement times for high resolution PDF (Pair-Distribution-Function) measurements to times as fast as 30 milliseconds, and have therefore opened up the potential scientific applications of the technique. Specifically this talk will cover both the development and operation of a dedicated PDF beamline at the APS and emerging scientific opportunities applying the PDF technique, including, (1) time-resolved PDF measurements, (2) the use of the technique to probe the structure of reactive sites at surfaces, (3) PDF measurements at high pressures, and (4) spatially resolved PDF measurements.