Prof Peter Nellist is Professor of Materials and leads a group at Oxford focusing on the development and applications of Scanning Transmission Electron Microscopy (STEM). He is an international leader in high resolution STEM, and made has made major developments in ADF atomic-resolution STEM imaging and spectroscopy using aberration correction, 3D imaging through optical sectioning and on phase retrieval using electron ptychography. He was leader of the “Imaging” work-package in ESTEEM2. He has won the Burton Medal of the MSA Microscopy Society of America, the Ernst Ruska Prize of the German Electron Microscopy Society and the European Microscopy Society Best Paper in Materials Science Prize for 2015. He is currently Vice-President (and formerly President) of the Royal Microscopical Society.
Title: Quantitative atomic resolution structure determination in 2D and 3D using STEM imaging
Recent developments in the optics, detectors and control methods for the scanning transmission electron microscope (STEM) enable a number of new approaches to quantitative structure determination of materials. Methods to accurately calibrate the ADF, EELS and EDX detectors allow 3D structures of catalyst nanoparticles to be determined. These structures can be used as the basis for electronic structure calculations. Measurement of the entire STEM detector plane as a function of probe position enables ptychography to be used for sensitive light element imaging and also to image charge transfer in a polar material.