Imagine that you are filming a football match, and the shutter speed of the camera is too slow to keep up with the speed of the players, they will appear opaque and blurred, and conversely if we use a sophisticated camera with a large shutter speed, the image of the players will be completely clear.
Scientists have previously known that the movement of molecules and atoms within materials can improve the performance of renewable energy applications, such as converting sunlight or converting waste heat into electricity.
Researchers at Columbia University in the United States, in collaboration with researchers from the University of Bourgogne in France, have developed a new camera that can image the movement of atoms inside materials, or what is known as "dynamic perturbance," and published the results in the journal Nature Material.
What is dynamic turbulence within materials?
Dynamic disorder within materials occurs when groups of atoms in a substance move in certain ways, over a period of time, due to exposure to vibration or due to temperature changes, and studying this movement is important to improve the properties and interactions of materials.
Unfortunately, it was difficult to study dynamic turbulence and understand what it was, because it was impossible to see it, because the shutter speed of the cameras was slow compared to the speed of the atoms, and therefore not enough to photograph it.
The fastest digital cameras on the market have a shutter speed of about 4 milliseconds, and to capture this movement it is necessary to develop a faster shutter speed.
Atom structures blurry with a normal camera and clear at the same shutter speed a trillion times faster (Jill Hamann - Columbia University)
How were scientists able to visualize dynamic disorder?
The research team conducted their experiment using a regular camera, the shutter of which was slow, and the image of the structures of the atoms appeared blurry. In contrast, the image of the structures of the atoms was clear when they used another camera at a high shutter speed of about one pico/second or a trillion times faster than a normal camera's shutters.
Simon Pilling, a professor of materials science, applied physics and applied mathematics at Columbia University, said in a press release published on the university's website on March 7, "We used a new tool that enabled us to see the dynamic disturbance in materials in the eye view, the Atomic Pair Distribution Function (vsPDF).
The atomic pair distribution function technique relies on the use of neutrons to monitor the position of atoms, and the researchers have applied it to germanium telluride (GeTe), which is widely used because of its distinctive properties in converting waste heat into electricity, or converting electricity into cooling.
The study of the dynamic motion of atoms within materials is important to improve their properties and interactions (Shutterstock)
Development of the environmentally friendly devices industry
The camera revealed that the structures of atoms in germanium telluride remained as uniform as crystal at almost all temperatures, but at high temperatures, the atoms were dynamically turbulent, and the kinetic energy (turbulence) in the atoms was converted into thermal energy.
Understanding the dynamic turbulence of atoms within materials leads to the development of environmentally friendly thermoelectric devices to be more energy efficient, such as refrigerators and heat pumps, in addition to improving the process of recovering energy from waste heat from car exhaust and using it to convert heat into electricity, and developing tools that power Mars rovers when sunlight disappears.
At the moment, this technique is not yet ready for use, but with further development it will become the most important method of probing materials. The Columbia University science professor and his research team are now working to present their research to the scientific community in an accessible way and apply it to other materials.