Ferroelastic Toughening in Bismuth Vanadate

Bismuth vanadate has been used as a model system to examine toughening by stress-induced domain motion in a ferroelastic material. Fracture toughnesses in the ferroelastic and paraelastic states have been compared. Toughening and R-curve behavior have been observed in the ferroelastic state. Single crystals of BiVO_4 show domain nucleation and propagation under compressive loading and domain generation during fracture. The increase in toughening in the ferroelastic state can be explained by a combination of crack deflection and domain wall motion, the latter contributing to R-curve behavior.