Chemically sensitive imaging with soft X-ray STXM and ptychography
by
Maria Skłodowska-Curie Room
ALBA Synchrotron
Abstract
Soft X-ray scanning transmission microscopy (STXM) is a powerful tool for spatially resolved chemical analysis at the nanoscale. Ptychography (scanning coherent diffraction imaging) can be measured using STXMs equipped with a suitable, post specimen X-ray camera. Ptychography provides significant improvements in spatial resolution (~10 nm, as opposed to ~30 nm for conventional STXM). This seminar will give an overview of STXM and ptychography with examples from biology, chemistry and materials science. Recent soft X-ray STXM and ptychography studies of Cu catalysed CO2 electro-reduction, with in situ control of electrolyte composition, flow rate, and electrochemical potential, will be featured.
Biography
Adam Hitchcock was born and educated in Canada (B.Sc., Chemistry, McMaster, 1974; Ph.D., Chemical Physics, UBC, 1978). His research focus is inner shell excitation spectroscopies and spectromicroscopies by electron beams and X-rays. A professor at McMaster since 1979, his group has studied inner shell electron energy loss (EELS) spectroscopy of gases and surfaces, using home built instruments. In 1980 he started synchrotron experiments, initially hard X-ray spectroscopy of materials at Cornell (USA), then soft X-ray spectroscopy of gases at LURE (France), SRC (USA) and Bessy-I. In 1994 he began research with soft X-ray transmission microscopy (STXM) and photoelectron emission microscopy (PEEM) at the ALS (USA). He helped establish the Canadian Light Source (CLS, Saskatoon) and the CLS spectromicroscopy beamline, currently equipped with 2 STXMs and a PEEM. In 2006, he was awarded fellowship of the Royal Society of Canada (FRSC, Canada’s highest scientific honor), for his contributions to development of X-ray microscopy and the CLS. His current research is focused on technique developments of STXM and ptychography, and their application to studies of energy materials, such as catalysts for CO2 reduction with in situ control of electrolyte and potential.
