Another class of energy minimizing changes to GB character are illustrated by the phenomenon of grain rotation , which can occur during high-temperature plastic deformation or recrystallization , as well as at lower temperatures in nanocrystalline materials . The primary feature of grain rotation is the change in crystal orientation of one grain relative to its neighbors resulting in lower-energy GBs between them. However, when the misorientation between two grains changes there will also be an accompanying change to the GB plane inclination . Consequently, such GB character transformations represent more general paths through the 5D GB character space that are not restricted to any misorientation or boundary plane subspaces.