Tuning ferroelectricity and ferromagnetism in BiFeO/BiMnO superlattices

• Published in: Nanoscale 2020-05, Vol.12 (17), p.981-9816
• Main Authors: Jin, Cai, Geng, Wanrong, Wang, Linjing, Han, Wenqiao, Zheng, Dongfeng, Hu, Songbai, Ye, Mao, Xu, Zedong, Ji, Yanjiang, Zhao, Jiali, Chen, Zuhuang, Wang, Gan, Tang, Yunlong, Zhu, Yinlian, Ma, Xiuliang, Chen, Lang
• Format: Article
• Language: English
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c9nr09670a

Multiferroic materials with multifunctional characteristics play a critical role in the field of microelectronics. In a perovskite oxide, ferroelectric polarization and ferromagnetism usually cannot coexist in a single-phase material at the same time. In this work, we design a superlattice structure composed of alternating BiFeO 3 and BiMnO 3 layers and illustrate how tuning the supercell size of epitaxial BiFeO 3 /BiMnO 3 superlattices facilitates ferroelectric polarization while maintaining relatively strong ferromagnetism. A comprehensive investigation reveals that the enhanced ferroelectric polarization of BiMnO 3 layers originates from the induction effect induced by a strong polarization field generated by the adjacent ferroelectric BiFeO 3 layers. For the magnetic behavior, we consider the existence of interfacial antiferromagnetic superexchange interaction of Fe-O-Mn between BiFeO 3 and BiMnO 3 layers in our superlattices. This modulation effect of artificial superlattices provides a platform to accurately control the multiple order parameters in a multiferroic oxide system. Superlattice structure provides an effective path for integrating multifunctional properties. The interfacial coupling in the ferromagnetic/ferroelectric superlattices is a possible route to achieve multiferroicity.