
Argonne materials scientist Andrew Ulvestad examines a sample.
A new X-ray technique could allow doctors to see inside continuously packed nanoparticles in the human body to examine deformations and dislocations that impact their properties.
Researchers from the U.S. Department of Energy’s Argonne National Laboratory have used an X-ray scattering technique called the Bragg coherent diffraction imaging to reconstruct the size and shape of the continuously packed nanoparticles, also known as grains, in 3D.
“This technique provides very high sensitivity to atomic displacements, as well as the ability to study materials under a number of different realistic conditions, such as high temperatures,” Argonne physicist Wonsuk Cha, an author the paper, said in a statement.
The researchers specifically focused on the area between particles called the grain boundary—which governs a lot of underlying activity.
Scientists have looked at the defect structure of separated nanoparticles over the past decade but didn’t have a way to see the distortions in the crystal lattice in grains that formed continuous films of material, such as those found in some solar cells or certain catalytic materials.
Using the Bragg coherent diffraction imaging, the researchers were able to shine X-rays at a sample and scatter off the atoms in the material’s structure, allowing them to reconstruct the material’s composition in 3D.
It is relatively simple to gather information from small isolated nanoparticles but difficult to find information in thin films.
“It’s like trying to figure out where Paul McCartney is in the iconic photo of Abbey Road versus trying to figure out where the sixth violinist in a large orchestra is,” Argonne materials scientist Andrew Ulvestad, an author of the study, said in a statement.
According to Ulvestad, thin-film solar cells could be an example of a material that scientists can learn more about from this new technique.
“These are usually pretty complicated materials whose behavior is largely determined by the atoms that are on the ‘front lines,’ near the grain boundaries,” Ulvestad said.
Dislocations near grain boundaries are controlled with the defect structure in the material and the new technique could enable scientists to gain the ability to control the synthesis and position of the defects, which will ultimately allow them to control the behavior of materials near the grain boundary.
The study was published in Science.