Electroelastic fields in artificially created vortex cores in epitaxial BiFeO₃ thin films

We employ phase-field modeling to explore the elastic properties of artificially created 1-D domain walls in (001)_p-oriented BiFeO₃ thin films, composed of a junction of the four polarization variants, all with the same out-of-plane polarization. It was found that these junctions exhibit peculiarly high electroelastic fields induced by the neighboring ferroelastic/ferroelectric domains. The vortex core exhibits a volume expansion, while the anti-vortex core is more compressive. Possible ways to control the electroelastic field, such as varying material constant and applying transverse electric field, are also discussed.