Mixed-state electron ptychography enables sub-angstrom resolution imaging with picometer precision at low dose.

Abstract
Both high resolution and high precision are required to quantitatively determine the atomic structure of complex nanostructured materials. However, for conventional imaging methods in scanning transmission electron microscopy (STEM), atomic resolution with picometer precision cannot usually be achieved for weakly-scattering samples or radiation-sensitive materials, such as 2D materials. Here, we demonstrate low-dose, sub-angstrom resolution imaging with picometer precision using mixed-state electron ptychography. We show that correctly accounting for the partial coherence of the electron beam is a prerequisite for high-quality structural reconstructions due to the intrinsic partial coherence of the electron beam. The mixed-state reconstruction gains importance especially when simultaneously pursuing high resolution, high precision and large field-of-view imaging. Compared with conventional atomic-resolution STEM imaging techniques, the mixed-state ptychographic approach simultaneously provides a four-times-faster acquisition, with double the information limit at the same dose, or up to a fifty-fold reduction in dose at the same resolution.

Citation
Chen, Z., Odstrcil, M., Jiang, Y., Han, Y., Chiu, M.-H., Li, L.-J., & Muller, D. A. (2020). Mixed-state electron ptychography enables sub-angstrom resolution imaging with picometer precision at low dose. Nature Communications, 11(1). doi:10.1038/s41467-020-16688-6

Acknowledgements
Z.C. and D.A.M. are supported by the PARADIM Materials Innovation Platform program in-house program by NSF Grant DMR-1539918. Y.H. is supported by the NSF MRSEC program (DMR-1429155). This work made use of the Cornell Center for Materials Research facility supported by NSF grant DMR-1719875. We thank Tsai Esther Hsiao Rho and Manuel Guizar-Sicairos for useful discussions.

Publisher
Springer Nature

Journal
Nature communications

DOI
10.1038/s41467-020-16688-6

PubMed ID
32533001

Additional Links
http://www.nature.com/articles/s41467-020-16688-6
https://www.nature.com/articles/s41467-020-16688-6.pdf

Relations
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  • [Dataset]
    Chen, Z., Odstrcil, M., Jiang, Y., Han, Y., Chiu, M.-H., Li, L.-J., & Muller, D. (2020). Dataset: Mixed-state electron ptychography enables sub-angstrom resolution imaging with picometer precision at low dose [Data set]. PARADIM, an NSF Materials Innovation Platform. https://doi.org/10.34863/G4WA-0J57. DOI: 10.34863/g4wa-0j57 Handle: 10754/668436

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