Small Volumes Create Super(elastic) Effects

Anyone who has ever broken a favorite coffee cup knows that ceramic materials do not accommodate strain well. Ceramic materials typically fail at strains (extensions) of less than 0.1%. On page 1505 of this issue, Lai et al. (1) demonstrate a class of ceramics that can deform reversibly by more than 7%, rendering these solids "superelastic." To put this in context, at 7% strain, an aluminum can would crumple with no hope of recovery. When Lai et al. made small chemical changes to their ceramics, they found a memory effect, whereby the solid can be permanently deformed, but upon heating reverts back to its original size and shape.