Vortex structure in relaxed BaTiO₃/SrTiO₃ superlattice

Abstract

Abstract In this work, using the phase-field model, we demonstrated vortex structure can be generated in a lead-free BaTiO 3 /SrTiO 3 superlattice structure. The labyrinth pattern (maze-like) domain structure was observed in a fully relaxed BaTiO 3 /SrTiO 3 superlattice structure. Topological bubble-like rosette structures were found at an out-of-plane field, and polar skyrmions were obtained after the electric field was removed. In a designed fully relaxed nanowire of width ∼8 nm, near-perfect periodical clockwise-counterclockwise ferroelectric vortex pairs were generated due to the interfacial constraints. The simulated topological structures are potentially relevant to the application of high-density ferroelectrics memory devices.