Impurity clouds from all sides now
By Corinna Wu
In crystalline materials such as steel, imperfections at the atomic scale can have a huge effect on gross mechanical properties. For example, line defects known as dislocations—where extra planes of atoms crowd into the regular crystal structure—significantly alter strength and flexibility.
Researchers know that atoms of any additive that may be present tend to collect around a dislocation, pinning it down and making the crystal less flexible. Now, for the first time, scientists have obtained three-dimensional images of these clouds of additive atoms, known as Cottrell atmospheres.