In the ongoing search for new materials for fuel cells, batteries, photovoltaics, separation membranes, and electronic devices, one newer approach involves applying and managing stresses within known materials to give them dramatically different properties. This development has been very exciting, says MIT associate professor of nuclear science and engineering Bilge Yildiz, one of the pioneers of this approach: “Traditionally, we make materials by changing compositions and structures, but we are now recognizing that strain is an additional parameter that we can change, instead of looking for new compositions.” Yildiz, who authored a recent Materials Research Society Bulletin paper describing work in this field, explains that “even though we are dealing with small amounts of strain” — displacing atoms within a structure by only a few percent — “the effects can be exponential,” in some cases improving key reaction rates by tenfold or more. While it may seem surprising that small displacements of atoms within a crystal lattice could have such large effects, Yildiz explains that in a normal, unstrained crystal structure, “atoms are at equilibrium positions. If you apply a strain, they are moved slightly from those equilibrium positions,” but their atomic bonds are not broken. However, the forces trying to pull
The post Strain can alter materials’ properties has been published on Technology Org.
#materials
See Zazzle gifts tagged with 'science'
No comments:
Post a Comment