The greatest digital cameras available today open their shutter for about one fourth of a second to take an image.
A shutter that clicks far more quickly would be necessary to capture atomic activity.
In light of this, researchers have developed a technique to produce shutter speeds that are 250 million times faster than those of modern digital cameras—a mere trillionth of a second. That makes it capable of capturing dynamic disorder, which is crucial in materials research.
Simply described, it occurs when certain atomic clusters move and dance within a material over an extended length of time, often in response to a vibration or a change in temperature. Although we still don’t fully get it, this phenomena is essential to understanding how materials behave and react.
The new ultra-rapid shutter speed system, which was unveiled in March of this year, gives us a lot better understanding of the dynamics of dynamic disorder. The term “variable shutter atomic pair distribution function,” or “vsPDF,” is used by the researchers to describe their creation.
Only with this new vsPDF technology, according to materials scientist Simon Billinge of Columbia University in New York, can we truly perceive this side of materials.
With this method, we will be able to observe a material and determine which atoms are participating and which are watching from the sidelines.
For quickly moving objects, such as rapidly jittering atoms, a quicker shutter speed produces a more accurate snapshot of time. If you take a picture of a sporting event with a slow shutter speed, the players in the picture will be blurry.
Instead of using traditional photographic methods, vsPDF measures the location of atoms using neutrons to accomplish its impressively rapid snap. Neutrons can be tracked as they enter and exit a material to quantify the atoms present, with variations in their energy levels acting as a shutter’s shutter speed.
These differences in shutter speed, together with the trillionth-of-a-second shutter speed, are important because they help distinguish between dynamic disorder and the related but different static disorder—the usual background jiggling of atoms on a material’s surface that does not improve its function.
“It gives us a whole new way to untangle the complexities of what is going on in complex materials, hidden effects that can supercharge their properties,” remarked Billinge.
In this instance, the scientists focused their neutron camera on a substance known as germanium telluride (GeTe), which is frequently used to convert waste heat into power or electricity into cooling due to its unique features.
The camera showed that, on average, at all temperatures, GeTe maintained its crystallographic structure. A gradient that matches the direction of the material’s spontaneous electric polarization was followed by the atoms as they exchanged motion for thermal energy at higher temperatures, however, exhibiting more dynamic disorder.
We can create better materials and equipment, such as the devices that power Mars rovers when sunlight isn’t accessible, by better understanding these physical structures and how thermoelectrics functions.
The scientific understanding of these materials and processes can be enhanced by models based on observations made by the new camera. For vsPDF to be a commonly utilized testing method, there is still a lot of work to be done.
“We anticipate that the vsPDF technique described here will become a standard tool for reconciling local and average structures in energy materials,” the researchers wrote in their report.
The research was published in Nature Materials.
