Scientists capture atomic motion in four dimensions for the first time

Scientists have for the first time captured atomic nucleation in 4D, the movement of atoms across space and time.

Nucleation is the coalescence of atoms and molecules that happens as matter changes states -- during freezing, melting or evaporation. Using a new high-tech imaging technique, scientists were able observe the movement of atoms during nucleation in four dimensions.

"This is truly a groundbreaking experiment -- we not only locate and identify individual atoms with high precision, but also monitor their motion in 4D for the first time," Jianwei "John" Miao, professor of physics and astronomy at UCLA, said in a news release.

Using a powerful electron microscope at Berkeley Lab's Molecular Foundry, researchers deployed an imaging technique called "atomic electron tomography." As a molecular sample spins, the microscope captures 3D images of the atoms inside the sample.

For their experiments, scientists used the novel imaging technology to observe iron-platinum alloy nanoparticles as they were heated to 968 degrees Fahrenheit, a temperature that triggers a transition between two different solid phases. Researchers snapped 3D images after 9 minutes, 16 minutes and 26 minutes.

Before heating, the alloy's internal structure is more haphazard. Images of the atomic movements showed the material's atomic structure takes on a more rigid pattern, with alternating layers of iron and platinum atoms, after being heated.

Scientists were able to track the movements of the same 33 nuclei, some containing as few as 13 atoms, at 9 minutes, 16 minutes and 26 minutes.

Until now, scientists assumed nuclei were relatively round and boasted a sharp boundary, but the new imaging breakthrough showed nuclei formed irregular shapes. Images showed each nuclei was formed by a collection of atoms that had adopted the structure of the new phase. However, the atoms closer to the center of the nuclei were more disorganized than the atoms farther away.

During the phase transition, scientists observed nuclei shrinking, dividing, merging and even disappearing. Previous theories of nucleation posited that nuclei, once formed, can only get bigger and bigger.

"Nucleation is basically an unsolved problem in many fields," said Peter Ercius, a staff scientist at the Molecular Foundry. "Once you can image something, you can start to think about how to control it."

The new findings -- published this week in the journal Nature -- may force scientists to rethink the atomic models describing a variety of chemical and physical phenomena.

Related Links
Understanding Time and Space

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Electron-behaving nanoparticles rock current understanding of matter
Chicago IL (SPX) Jun 24, 2019
It's not an electron. But it sure does act like one. Northwestern University researchers have made a strange and startling discovery that nanoparticles engineered with DNA in colloidal crystals - when extremely small - behave just like electrons. Not only has this finding upended the current, accepted notion of matter, it also opens the door for new possibilities in materials design. "We have never seen anything like this before," said Northwestern's Monica Olvera de la Cruz, who made the initial ... read more