Vortex Domain Walls in Ferroelectrics

Zijian Hong; Sujit Das; Christopher Nelson; Ajay Yadav; Yongjun Wu; Javier Junquera; Long-Qing Chen; Lane W Martin; Ramamoorthy Ramesh

doi:10.1021/acs.nanolett.1c00404

Vortex Domain Walls in Ferroelectrics

Nano Lett. 2021 Apr 28;21(8):3533-3539. doi: 10.1021/acs.nanolett.1c00404. Epub 2021 Apr 19.

Authors

Zijian Hong^{1

2

3}, Sujit Das⁴, Christopher Nelson⁵, Ajay Yadav⁴, Yongjun Wu^{1

3}, Javier Junquera⁶, Long-Qing Chen⁷, Lane W Martin^{4

8}, Ramamoorthy Ramesh^{4

8

9}

Affiliations

¹ Laboratory of Dielectric Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
² Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, Zhejiang 311200, China.
³ Cyrus Tang Center for Sensor Materials and Applications, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China.
⁴ Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States.
⁵ Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6071, United States.
⁶ Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenidad de los Castros s/n, E-39005 Santander, Spain.
⁷ Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
⁸ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
⁹ Department of Physics, University of California, Berkeley, California 94720, United States.

PMID: 33872021
DOI: 10.1021/acs.nanolett.1c00404

Abstract

Controlling the domain formation in ferroelectric materials at the nanoscale is a fertile ground to explore emergent phenomena and their technological prospects. For example, charged ferroelectric domain walls in BiFeO₃ and ErMnO₃ exhibit significantly enhanced conductivity which could serve as the foundation for next-generation circuits (Estévez and Laurson, Phys. Rev. B 2015, 91, 054407). Here, we describe a concept in which polar vortices perform the same role as a ferroelectric domain wall in classical domain structures with the key difference being that the polar vortices can accommodate charged (i.e., head-to-head and tail-to-tail) domains, for example, in ferroelectric PbTiO₃/dielectric SrTiO₃ superlattices. Such a vortex domain wall structure can be manipulated in a reversible fashion under an external applied field.

Keywords: Charged domain wall; Ferroelectric superlattices; Phase-field simulations; Vortex domain wall.