Engineered periodic quadrupole superstructure in ferroelectric thin films via flexoelectricity

Abstract Domain engineering of nanoferroelectrics becomes crucial due to the miniaturization of devices. Understanding the geometric ordering of nanodomains that self-organize into superstructures helps to develop modern domain engineering techniques. Here, using the phase field simulation, we find that large flexoelectricity in thin films can contribute to exotic in-plane needle-like and quadrupole superdomains. Our results indicate that by pressing a mesh of atomic force microscope tips on the film surface, the tip-induced flexoelectric field can tune the polarization nucleation during cooling and lead the nanodomains to evolve into periodic quadrupole patterns. Our work suggests a new approach to create and manipulate desired superstructures and offers a framework of developing engineering techniques in conjunction with phase-field modeling.