Specimen drift presents a fundamental challenge for high-resolution electron microscopy. Exposure of the sample to electrons may itself cause beam-induced motion. For in situ experiments, stimulation of the specimen with electrical impulses, mechanical deformation, heating, or laser irradiation leads to large amounts of movement. Such issues can be alleviated with fast electron cameras, which allow micrographs to be recorded as movies so that drift can be removed computationally by aligning individual frames to each other. However, the amount of drift that can be removed with dose-fractionated imaging, as well as the time resolution of in situ experiments, is ultimately limited by the frame rate of the electron camera.
We circumvent these limitations by recording images with high-brightness electron pulses in combination with a fast electron camera. These pulses contain a sufficient number of electrons to capture structural information in a single shot, while being coherent enough to enable atomic-resolution. This allows us to obtain atomically-resolved images even when severe specimen drift is present. Moreover, these short electron pulses enable us to observe atomic-scale changes on microsecond timescales, such as the crystallization pathways of individual nanoparticles as well as the high-temperature transformation of perovskite nanocrystals.
Electron diffraction of deeply supercooled water in no man’s land
C.R. Krüger, N.J. Mowry, G. Bongiovanni, M. Drabbels, U. J. Lorenz. Nat Commun 14, 2812 (2023)
Atomic-Resolution Imaging of Fast Nanoscale Dynamics with Bright Electron Pulses. P.K. Olshin, G. Bongiovanni, M. Drabbels, U.J. Lorenz. Nano Lett. 21 (1), 612–618 (2021)
Intense Microsecond Electron Pulses from a Schottky Emitter. G. Bongiovanni, P.K. Olshin, M. Drabbels, U.J. Lorenz. Appl. Phys. Lett. (Editor’s Choice) 116, 234103 (2020)