Title: Putting the back focal plane back into STEM
Abstract: The back focal plane of a sample in transmission electron microscopy is full of a fascinating array of information, as will be clear to anyone who grew up reading Hirsch, Howie, Nicolson, Pashley and Whelan (aka “The Yellow Bible”). STEM, however, has mainly concentrated on incoherent imaging with high angle scattered electrons. More recently, interest has increased in using bright field imaging in STEM for visualising light atoms. However, there is a whole richness of information which was mostly neglected until recently - the inability to read out any detail of the back focal plane at a high frame rate. This has now changed with the advent of fast pixelated direct electron detectors. In this talk, I will review work going on at Glasgow in partnership with the group of Prof Peter D Nellist at Oxford on applying fast pixelated detectors to STEM imaging. This will cover imaging of magnetisation in ferromagnetic nanostructures, ultrastructure in biological cells, short and medium range ordering in glasses, phase contrast imaging at atomic resolution, and ordering along the beam direction for perovskite oxides.
Cm-Bio 7-21 MacLaren