Beyond 2D: Advanced Electron Microscopy for Bonding and Structure

Abstract:

Electron microscopy is the go-to tool for imaging of materials at the nanoscale, but microscopy techniques that utilize 3-, 4-, or even 5-dimensional datasets move beyond simple imaging to offer unprecedented insight into material properties. This talk will cover several case studies showcasing the potential of 3D and 4D electron microscopy datasets. First, we will examine bonding and local ordering in nitride semiconductors using electron energy loss spectroscopy. Next, we will showcase nanometer-resolution strain and polarity mapping of ferroelectric perovskite oxides via novel analysis of 4D scanning transmission electron microscopy (4D-STEM) data. Finally, we will demonstrate in-situ grain mapping of 2D materials using a cutting-edge 4D-RHEED (reflection high-energy electron diffraction) technique in development at NIST.

Speaker bio:

Allison Mis is a postdoctoral researcher at the National Institute of Standards and Technology (NIST) in Boulder, Colorado. Her research focuses on developing electron microscopy techniques to answer pressing materials science questions on the nanoscale. She has studied novel semiconducting pnictides, ultra-wide-bandgap materials, ferroelectric oxides, and is excited to have recently branched out into 2D materials.