Abstract: Contemporary effort in analytical sciences is punctuated by a seemingly never-ending search for improved multiscale characterization and modeling of complex, functional materials. Work toward the next generation of photovoltaics, catalysts, thermoelectrics, and batteries shares the message that disorder is ubiquitous from the atomic scale to the macroscale. This places a high emphasis on diagnostic methods that do not require long-range order, such as electron microscopies and also many different spectroscopies. This seminar will focus on two advanced x-ray spectroscopies, x-ray absorption fine structure (XAFS) and x-ray emission spectroscopy (XES). XAFS, in particular, has a long history of use exactly in problems where only short-range order exists, but these methods have the twin reputation of being specialist methods (for specialist problems) and for having very low access confined to synchrotron x-ray light sources. This situation is rapidly changing on two fronts. First, new technology for laboratory-based XAFS and XES and changes in access policies and beamline equipment at some synchrotron light sources are greatly lowering the access barriers to these methods. Second, the use of modern hybrid theoretical methods of the materials genome and machine learning are allowing XAFS to be used on a wider range of real materials challenges and with higher impact. In this seminar, I will give a summary of the underpinnings of these x-ray spectroscopies, and then discuss the twin developments in new access and new application.
Biography: After studies at the University of Florida and the University of Chicago, Professor Gerald Seidler was a postdoctoral fellow at NEC Research Institute and then joined the University of Washington Physics Department in 1996. At the UW his work has centered on the development and application of advanced x-ray methods, both at synchrotron light sources and in the laboratory. Professor Seidler’s group has recently led a growing renaissance of benchtop spectrometers for measurement of x-ray absorption fine structure (XAFS) and x-ray emission spectroscopy (XES), with an emphasis on new analytical uses of these methods for materials discovery, industrial application, and regulatory compliance. In 2015 he co-founded easyXAFS LLC, which is commercializing the UW technology.