A team of Foundry scientists and users developed 4D (3D+time) atomic electron tomography to directly image the dynamics of chemical structure changes at the atomic scale.
Significance and Impact
The new technique captured nucleation, growth, dissolution, and merging of grains at the atomic scale showing limitations in current nucleation theories. These processes are fundamental processes of most synthesis processes which this technique can now study directly.
Using FePt nanoparticles as a model system, the researchers performed atomic electron tomography on particles that were heated to cause a change from a chemically disordered to ordered phase.
- Heating was stopped at different times to capture the transformation through time.
- Molecular dynamics simulations found that a theory beyond Classical Nucleation Theory will be required to describe early stage nucleation at the atomic scale.
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 & J. Miao, Nature. 2019 DOI: 10.1038/s41586-019-1317-x
This work has been highlighted by the Department of Energy Office of Science.