Ferroelectric Proximity Effect and Topological Hall Effect in SrRuO3/BiFeO3 Multilayers

Xiaokang Yao; Can Wang; Er-Jia Guo; Xinyan Wang; Xiaomei Li; Lei Liao; Yong Zhou; Shan Lin; Qiao Jin; Chen Ge; Meng He; Xuedong Bai; Peng Gao; Guozhen Yang; Kui-Juan Jin

doi:10.1021/acsami.1c21703

Ferroelectric Proximity Effect and Topological Hall Effect in SrRuO₃/BiFeO₃ Multilayers

ACS Appl Mater Interfaces. 2022 Feb 2;14(4):6194-6202. doi: 10.1021/acsami.1c21703. Epub 2022 Jan 24.

Authors

Xiaokang Yao^{1

2}, Can Wang^{1

2

3}, Er-Jia Guo^{1

2

3}, Xinyan Wang^{1

2}, Xiaomei Li^{1

2

4}, Lei Liao^{1

2}, Yong Zhou^{1

2}, Shan Lin^{1

5}, Qiao Jin^{1

2}, Chen Ge^{1

2}, Meng He¹, Xuedong Bai^{1

2

3}, Peng Gao⁴, Guozhen Yang^{1

2}, Kui-Juan Jin^{1

2

3}

Affiliations

¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
² School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
³ Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China.
⁴ International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
⁵ Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 35072446
DOI: 10.1021/acsami.1c21703

Abstract

Interfaces between complex oxides provide a unique opportunity to discover novel interfacial physics and functionalities. Here, we fabricate the multilayers of itinerant ferromagnet SrRuO₃ (SRO) and multiferroic BiFeO₃ (BFO) with atomically sharp interfaces. Atomically resolved transmission electron microscopy reveals that a large ionic displacement in BFO can penetrate into SRO layers near the BFO/SRO interfaces to a depth of 2-3 unit cells, indicating the ferroelectric proximity effect. A topological Hall effect is indicated by hump-like anomalies in the Hall measurements of the multilayer with a moderate thickness of the SRO layer. With magnetic measurements, it can be further confirmed that each SRO layer in the multilayers can be divided into interfacial and middle regions, which possess different magnetic ground states. Our work highlights the key role of functional heterointerfaces in exotic properties and provides an important guideline to design spintronic devices based on magnetic skyrmions.

Keywords: complex oxides; ferroelectric proximity effect; interfacial physics; magnetism; transport.