In 1959, Richard Feynman challenged: "It would be very easy to make an analysis of any complicated chemical substance; all one would have to do would be to look at it and see where the atoms are. I put this out as a challenge: Is there no way to make the electron microscope more powerful?"
Here, we introduce atomic electron tomography (AET), which addressses the Feynman's challenge and therefore allows to really "look and see"the 3D positions and atomic species of individual atoms without assuming crystallinity or using averaging. Please see below a YouTube Video made by the journal Nature Materials, "three-dimensional coordinates of individual atoms in materials revealed by electron tomography" [1].
The combination of the modern aberration-corrected electron microscopy technology and advanced 3D reconstruction methods we developed [2] has brought the resolution of electron tomography to the atomic scale, where individual atoms can clearly be observed [3]. From the atomic scale reconstructions, we can reveal the full 3D internal atomic structure of materials. Interesting structural details including 3D nano-grain structure, chemical order/disorder, anti-site defects, phase boundaries, point defects, 3D strain tensor, and even 4D atomic scale dynamics during the crystal nucleation can be accurately determined [2, 4-5]. This level of complexity has never been probed with conventional crystallography techniques. Moreover, we further demonstrated that the true atomic structure indeed provides important physical properties, such as magnetic moments or magnetocrystalline anisotropy, via quantum mechanical calculations [4] (please visit "FePt Nanoparticle 3D Atomic Structure" and "4D Atomic Scale Nucleation Dynamics" pages for more details).
The Feynman's 1959 challenge has been successfully addressed by AET at least for functional metallic nanoalloys. The ability to determine the 3D structure of crystal defects and noncrystalline systems at atomic resolution will transform our understanding of materials properties and functionality at the most fundamental level. However, this is just the beginning of the fascinating 3D atomic world. There are numerous important long-standing questions in materials physics where AET can provide important clues. Further developments of AET would allow atomic-level 3D localization and identification of complex systems (including dopants, interstitials, light elements, and vacancies), surfaces & interfaces, 2D materials, topological systems, amorphous materials, and many more. Ultimately, dynamics of individual atoms and defects in materials can be fully revealed by monitoring the motion and interaction of individual atoms in complex systems during phase transitions or under external mechanical stress.
1. R. Xu, C.-C. Chen, L. Wu, M. C. Scott, W. Theis, C. Ophus, M. Bartels, Y. Yang, H. Ramezani-Dakhel, M. R. Sawaya, H. Heinz, L. D. Marks, P. Ercius and J. Miao , "Three-Dimensional Coordinates of Individual Atoms in Materials Revealed by Electron Tomography", Nat. Mater. 14, 1099-1103 (2015).
2. A. Pryor Jr.*, Y. Yang*, A. Rana, M. Gallagher-Jones, J. Zhou, Y. H. Lo, G. Melinte, W. Chiu, J. A. Rodriguez and J. Miao, "GENFIRE: A generalized Fourier iterative reconstruction algorithm for high-resolution 3D imaging", Sci. Rep. 7, 10409 (2017). (*: equal contribution)
3. J. Miao, P. Ercius and S. J. L. Billinge, "Atomic electron tomography: 3D structures without crystals", Science 353, aaf2157 (2016). (Review)
4. Y. Yang*, C.-C. Chen*, M. C. Scott*, C. Ophus*, R. Xu, A. Pryor Jr., L. Wu, F. Sun, W. Theis, J. Zhou, M. Eisenbach, P. R. C. Kent, R. F. Sabirianov, H. Zeng, P. Ercius, and J. Miao, "Deciphering chemical order/disorder and material properties at the single-atom level", Nature 542, 75-79 (2017).(*: equal contribution)
5. J. Zhou*, Y. Yang*, Y. Yang, D. S. Kim, A. Yuan, X. Tian, C. Ophus, F. Sun, A. K. Schmid, M. Nathanson, H. Heinz, Q. An, H. Zeng, P. Ercius and Jianwei Miao, "Capturing nucleation at 4D atomic resolution", arXiv:1807.10709 (2018) [Nature, under review].(*: equal contribution)