Trillion-second camera captures clutter in action: ScienceAlert

To take a picture, the best digital cameras on the market open their shutter for about one four-thousandth of a second.

To photograph atomic activity, you’ll need a shutter that clicks more quickly.

With that in mind, scientists have revealed a way to achieve a shutter speed of only a trillionth of a second, or 250 million times faster than that of digital cameras. This makes him able to capture something very important in materials science: dynamic turbulence.

Simply put, it happens when groups of atoms in a material move and dance in certain ways over a certain period of time — due to vibration or a change in temperature, for example. It’s not a phenomenon we fully understand yet, but it’s important to the properties and interactions of materials.

The new ultra-fast shutter speed system, unveiled in March of this year, gives us even more insight into what’s going on with dynamic turbulence. The researchers refer to their invention as the shutter atomic pair variable distribution function, or vsPDF for short.

“Only with this new vsPDF tool can we really see this side of the material,” He said Materials scientist Simon Billinge of Columbia University in New York.

“With this technology, we’ll be able to watch a material and see which atoms are in the dance and which are sitting out.”

A faster shutter speed captures a more accurate shot of time, which helps fast-moving objects such as rapidly vibrating atoms. Use a low shutter speed on a sports game photo, for example, and you’ll end up with blurred players in the frame.

To achieve an amazingly fast snapshot, vsPDF uses neutrons to measure the position of atoms, rather than traditional imaging techniques. The way neutrons strike and pass through matter can be tracked to measure surrounding atoms, with changes in energy levels equivalent to shutter speed adjustments.

These differences in shutter speed are significant, in addition to the trillionth of a second shutter speed: they are vital in picking out dynamic turbulence from related and different static turbulence—the natural background vibrating on the spot of undressed atoms. Enhance the functionality of the material.

“It gives us a whole new way to untangle the complexities of what happens in complex materials, and the subtle influences that can augment their properties.” He said Invoices.

In this case, the researchers trained their neutron camera on a material called Germanium telluride (GeTe), which is widely used because of its special properties for converting waste heat into electricity, or electricity into cooling.

The camera revealed that GeTe remained crystal-like, in the middle, at all temperatures. At higher temperatures, however, it showed more dynamic disorder, as the atoms exchanged motion into thermal energy following a gradient that matches the direction of the material’s spontaneous electrical polarization.

A better understanding of these physical structures improves our knowledge of how thermoelectrics work, enabling us to develop better materials and equipment — such as instruments that power Mars rovers when sunlight is not available.

Through models based on observations captured by the new camera, scientific understanding of these materials and processes can be improved. However, there is still a lot of work to be done to prepare vsPDF to be a widely used testing method.

“We expect the vsPDF technology described here to become a standard tool for reconciling local and intermediate structures in energy materials,” say the researchers. to explain in their paper.

Research published in nature materials.

A previous version of this article was published in March 2023.