Inhomogeneity of structure and piezoelectric response of perovskite spherulitic islands in thin PZT films

The inhomogeneous distribution of the lateral piezoelectric response and surface potential over a spherulitic perovskite islands is studied. It is shown that the non-uniform distribution of the lateral piezoresponse is associated with the action of radial tensile mechanical stresses acting on the spherulitic island from the low-temperature pyrochlore matrix, as well as the formation of a negative space charge at the interface, leading to the formation of radial (lateral) self-polarization. It is assumed that the inhomogeneous radial distribution of the surface potential of the islands is caused by recrystallization of the perovskite phase.