M. Checa
Oak Ridge National Laboratory,
United States
Keywords: AFM, PFM, ferroelectrics
Summary:
Ferroelectric materials host rich polarization textures that emerge from the interplay between symmetry, strain, and electrostatic boundary conditions. Understanding how these polarization vectors evolve in three dimensions under applied bias is key to designing next-generation functional nanoelectronic systems. Here, we employ vector piezoresponse force microscopy (Vector PFM) to map the full three-dimensional polarization structure and its field-driven evolution across a range of complex ferroelectrics, including BiFeO₃, Pb₀.₆Sr₀.₄TiO₃, and epitaxial Pb(Zr,Ti)O₃ (111) thin films. Combining multidirectional ferroelectric writting with automated vector reconstruction, we directly visualize hierarchical ferroelectric domain structures. In Pb₀.₆Sr₀.₄TiO₃, we uncover trajectory-dependent superdomain formation driven by scan-path engineering; in BiFeO₃, we use those discoveries to nano-encode information in stabilized flux-closure domains ; and in PZT (111), we demonstrate distinct 3D switching pathways. These findings establish Vector PFM as a universal platform for probing 3D polarization vector fields at the nanoscale, and automation, needed to drive and control the switching process. This approach offers unprecedented insight into topological ferroelectric textures and paves the way toward programmable, multistate ferroic nanodevices.