Linking Domain Structure Evolution at a Grain Boundary to Piezoelectric Response via Nano‐Diffraction

ABSTRACT Electric‐field‐induced domain structure switching in a 1 ‐thick ( (Nb‐doped PZT) bicrystal film was characterized in situ via nano‐focused synchrotron diffraction. The epitaxial film was deposited on a (100) bicrystal substrate. The changes in domain structure were mapped within a 5 5 area at and around an in‐plane tilt‐type (23.6) grain boundary with 50 nm spatial resolution. Rocking curves collected at each point of the mapped area provided the ability to reconstruct spatially‐varying three‐dimensional (3D) reciprocal space maps around the grain boundary. The 3D reciprocal space maps reveal how different tilted ‐type domain variants interact with the grain boundary as a function of increasing electric field. Initially, a subset of ‐type domain variants with their polarization vectors largely orthogonal to the grain boundary were found in greater abundance within 570 nm of the grain boundary, possibly due to X‐ray beam‐induced local increases in the electrical conductivity, but after the coercive field was exceeded, reconfiguration of the ferroelastic domains was observed. The spatially‐varying reciprocal space maps also facilitated evaluation of the strain field across the mapped area, along with . Significant spatial heterogeneity of strain and are observed, especially at the coercive field, which was attributed to maintaining deformation compatibility and correlated ferroelastic switching.