Watching grain boundaries

Ceramics Grain boundaries play an important role in determining the properties of ceramics and other materials. However, tracking the migration of grain boundaries is difficult. Wei et al. used atomic-resolution scanning transmission electron microscopy to trigger and probe grain boundary migration in alumina. The authors found that cooperative shuffling of atoms at the grain boundary ledge is how migration proceeds, which leads to structural transitions. This new method for determining the fine details of these sorts of processes will help us better understand how microstructures develop in a range of materials. Nat. Mater. 20 , 951 (2021).