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
School of Physics, Harbin Institute of Technology, Harbin 150081, China.
Nanoscale. 2020 May 7;12(17):9810-9816. doi: 10.1039/c9nr09670a. Epub 2020 Apr 24.
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 and BiMnO layers and illustrate how tuning the supercell size of epitaxial BiFeO/BiMnO superlattices facilitates ferroelectric polarization while maintaining relatively strong ferromagnetism. A comprehensive investigation reveals that the enhanced ferroelectric polarization of BiMnO layers originates from the induction effect induced by a strong polarization field generated by the adjacent ferroelectric BiFeO layers. For the magnetic behavior, we consider the existence of interfacial antiferromagnetic superexchange interaction of Fe-O-Mn between BiFeO and BiMnO 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.
具有多功能特性的多铁性材料在微电子领域发挥着关键作用。在钙钛矿氧化物中，铁电极化和铁磁性通常无法在单相材料中同时共存。在这项工作中，我们设计了一种由交替的BiFeO和BiMnO层组成的超晶格结构，并说明了如何调整外延BiFeO/BiMnO超晶格的超胞尺寸，在保持相对较强铁磁性的同时促进铁电极化。全面研究表明，BiMnO层增强的铁电极化源于相邻铁电BiFeO层产生的强极化场引起的诱导效应。对于磁行为，我们考虑了超晶格中BiFeO和BiMnO层之间Fe-O-Mn界面反铁磁超交换相互作用的存在。人工超晶格的这种调制效应为精确控制多铁性氧化物系统中的多个序参提供了一个平台。
