M.F. Murfitt

TL;DR: Annular dark-field imaging in an aberration-corrected scanning transmission electron microscope optimized for low voltage operation can resolve and identify the chemical type of every atom in monolayer hexagonal boron nitride that contains substitutional defects.

TL;DR: Using a fifth-order aberration-corrected scanning transmission electron microscope, which provides a factor of 100 increase in signal over an uncorrected instrument, two-dimensional elemental and valence-sensitive imaging at atomic resolution is demonstrated by means of electron energy-loss spectroscopy.

TL;DR: Direct images from an aberration-corrected scanning TEM are presented that resolve a lattice in which the atomic columns are sepa-rated by less than 0.1 nanometer.

TL;DR: This work has designed and built an entirely new scanning transmission electron microscope (STEM), which includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors.

TL;DR: The method of high efficiency ptychography produces the clearest images, while annular bright field produces almost no contrast for an in-focus aberration-corrected probe.