Domain switching in process zones of PZT: characterization by microdiffraction and fracture mechanical methods

Ferroelastic domain switching in the vicinity of cracks in Soft-PZT was examined by X-ray microdiffraction. Preliminary experiments under electrical and mechanical load proved the ability of the method to quantitatively characterize domain switching in the process zone of cracks with sufficient local resolution. Using an in situ bending device the observation of domain switching under load was possible. The width of the process zone at a growing crack, measured by microdiffraction can be correlated with the increase of the crack resistance curve measured in fracture mechanical tests. The separation of mechanical and ferroelastic contributions to the R-curves was performed by determining R-curves before and after unloading the samples. Residual stresses caused by domain switching could not be detected.