Fig. 1: Overview of STEM experiments in characterizing copper additives and CTAB surfactants on a gold nanocuboid surface.

A focused electron probe is scanned across the nanocuboid surface, and at each probe position electron signals are collected by various detectors. A EDX maps provide the location of additives (Cu) and surfactant counterion (Br) at nanometre resolution. B Conventional STEM integrates the diffraction pattern using a disc or annular detector. Top: <100> zone axis STEM-HAADF image of surfactant attached to the {100} facets; Bottom: Atomic resolution <110> zone axis STEM-BF image of surfactant attached to the edge where two {100} facets meet. Red-boxed images on the right are the magnified, rotated images of the red box annotation in the images on the left. C 4D-STEM collects the diffraction pattern at each probe position with a pixel array detector. Electron scattering simulations identify conditions for direct imaging of the nanocuboid-metal additive-surfactant interface. Under these conditions, a collection of diffraction patterns is acquired and a direct image of the nanocuboid-metal additive-surfactant interface is generated from which the atomic arrangement and distances will be measured.