Induction and Ferroelectric Switching of Flux Closure Domains in Strained PbTiO3 with Neural Network Quantum Molecular Dynamics. Academic Article uri icon

abstract

  • We have developed an extension of the Neural Network Quantum Molecular Dynamics (NNQMD) simulation method to incorporate electric-field dynamics based on Born effective charge (BEC), called NNQMD-BEC. We first validate NNQMD-BEC for the switching mechanisms of archetypal ferroelectric PbTiO3 bulk crystal and 180 domain walls (DWs). NNQMD-BEC simulations correctly describe the nucleation-and-growth mechanism during DW switching. In triaxially strained PbTiO3 with strain conditions commonly seen in many superlattice configurations, we find that flux-closure texture can be induced with application of an electric field perpendicular to the original polarization direction. Upon field reversal, the flux-closure texture switches via a pair of transient vortices as the intermediate state, indicating an energy-efficient switching pathway. Our NNQMD-BEC method provides a theoretical guidance to study electro-mechano effects with existing machine learning force fields using a simple BEC extension, which will be relevant for engineering applications such as field-controlled switching in mechanically strained ferroelectric devices.

published proceedings

  • Nano Lett

altmetric score

  • 1.25

author list (cited authors)

  • Linker, T. M., Nomura, K., Fukushima, S., Kalia, R. K., Krishnamoorthy, A., Nakano, A., ... Vashishta, P.

citation count

  • 1

complete list of authors

  • Linker, Thomas M||Nomura, Ken-Ichi||Fukushima, Shogo||Kalia, Rajiv K||Krishnamoorthy, Aravind||Nakano, Aiichiro||Shimamura, Kohei||Shimojo, Fuyuki||Vashishta, Priya

publication date

  • August 2023