Atomistic Simulation of Strain-Induced Domain Evolution in a Uniaxially Compressed BaTiO3 Single-Crystal Nanofilm

A barium titanate single-crystal nanofilm subjected to a monotonically increasing uniaxial compressive strain load is simulated with the molecular dynamics method based on the shell model. A three-stage evolution process of a 180A degrees stripe domain to a flux closure vortex-like domain consisting of four 90A degrees stripe domains, then to a vortex-antivortex-vortex array, and finally to a new 180A degrees stripe domain perpendicular to the initial stripe domain is observed when the strain varies from 0% to 2%. Both the stable condition and configuration of polarization vortexes in the compressed nanofilm are discussed.