For additional news stories please visit the News page.

Posted on: 12/14/2012 12:00:00 AM... Breakthrough research on the behavior of nickel nanocrystals under intense pressure was presented in the article, “Texture of Nanocrystalline Nickel: Probing the Lower Size Limit of Dislocation Activity,” in the December 14 issue of Science.

It is believed that permanent changes to metallic grains when under pressure are associated with the movement of structural irregularities in the grains. But the deformation of nanocrystalline materials has been controversial because it was thought that below a certain grain size, the structural irregularities would not form and the deformation would be dictated by motions of the boundary between grains instead. According to computer analysis, this critical limit would occur in nanocrystals at sizes between 10 and 30 nm in size.

Using radial diamond anvil cell x-ray diffraction, the article’s authors were able to show that the activities of the structural irregularities that accompany deformation were occurring even in nickel nanocrystals of 3 nanometers in size when they were compressed to higher than 183,000 times normal atmospheric pressure (18.5 gigapascals). This demonstrates that so-called dislocation-associated deformation is a function of both pressure and particle size, as previously thought, but that the particle size can be smaller than computer modeling had anticipated. These findings could help physicists and engineers create stronger, longer-lasting materials.

For More Information:

• Read Science Article

For additional news stories please visit the News page.