Regulation of flux-closure domain structures via oxygen vacancies and charged scanning probe microscopy

Abstract

Manipulation of topological structures has become one of the most interesting topics in ferroelectrics through multiple excitations due to their prospective applications in electro-mechanical-optic devices. Scanning probe microscopy (SPM) has been developed as a powerful tool to manipulate the polar state in ferroic materials, in which the electric field induced by charged SPM enables dynamic coupling between the switching of the polar states and electromigration of oxygen vacancies, resulting in unknown influences of oxygen vacancy on the polar state in ferroelectric topological structures. Here, we regulate the polar state by considering oxygen vacancies and a non-uniform electric field under the charged SPM experiment for flux-closure domain structures in PbTiO3 thin films. The charged SPM probe can excite the growth of newly flux-closure domains to improve the density of topological states. In contrast, oxygen vacancies are found to suddenly prohibit the evolution of the flux-closure domain structure, when their concentration jumps to a threshold value. Our results might give guidelines to increase and stabilize the memory unit through co-modulating the electric field and ions injection in the information field.