title: Practical aspects of diffractive imaging using an atomic-scale coherent electron probe.
abstract: Four-dimensional scanning transmission electron microscopy (4D-STEM) is a technique where a full two-dimensional convergent beam electron diffraction (CBED) pattern is acquired at every STEM pixel scanned. Capturing the full diffraction pattern provides a rich dataset that potentially contains more information about the specimen than is contained in conventional imaging modes using conventional integrating detectors. Using 4D datasets in STEM from two specimens, monolayer MoS2 and bulk SrTiO3, we demonstrate multiple STEM imaging modes on a quantitative absolute intensity scale, including phase reconstruction of the transmission function via differential phase contrast imaging. Practical issues about sampling (i.e. number of detector pixels), signal-to-noise enhancement and data reduction of large 4D-STEM datasets are emphasized.
authors: School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia. Electronic address: zhen.chen@monash.edu.
authors: Z
authors: Z
authors: Chen
authors: Monash Centre for Electron Microscopy, Monash University, Clayton, Victoria 3800, Australia; Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia.
authors: M
authors: M
authors: Weyland
authors: National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors: P
authors: P
authors: Ercius
authors: National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors: J
authors: J
authors: Ciston
authors: School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia; Department of Civil Engineering, Monash University, Clayton, Victoria 3800, Australia.
authors: C
authors: C
authors: Zheng
authors: School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia.
authors: M S
authors: MS
authors: Fuhrer
authors: School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
authors: A J
authors: AJ
authors: D'Alfonso
authors: School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
authors: L J
authors: LJ
authors: Allen
authors: School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia.
authors: S D
authors: SD
authors: Findlay
keywords: Convergent beam electron diffraction; Differential phase contrast; Diffractive imaging; Phase reconstruction