Recent advances in soft X-ray spectro-ptychography with Adam Hitchcock
Channel: LINXS
Date: 2023-05-30

The CoWork webinar series is dedicated to the exploitation of the coherence properties of X-rays for advanced materials characterization, with a special focus on inverse microscopy techniques, such as Coherent Diffraction Imaging (CDI), Ptychography and Holography. It is an introduction to Coherent X-ray imaging methods to facilitate the access to advanced microscopy techniques to new users and it welcomes all researchers intrigued by the spectacular coherence properties of X-rays produced at modern synchrotron sources – of which MAX IV is a first example. 

Bio: 
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. 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) and SRC (USA). In 1994 he began developing soft X-ray transmission microscopes (STXM) and photoemission microscopes (PEEM) at 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. 

Abstract: 
 Soft X-ray scanning transmission microscopy (STXM) is a powerful tool for nanoscale materials analysis, with significant advantages over analytical electron microscopies for studies of radiation sensitive materials, and for in situ and operando studies. Ptychography (scanning coherent diffraction imaging) can be measured using soft X-ray STXMs equipped with a suitable, post specimen X-ray camera. Ptychography provides significant improvements in spatial resolution (~10 nm, as opposed to 20-30 nm for conventional STXM) as well as additional information from phase imaging. This seminar will describe recent advances in soft X-ray spectro-ptychography include extension to low X-ray energies (lt. 200 eV), and in situ flow electrochemical studies of Cu catalysts for CO2 reduction.