Tao Ang, Jiang Yixiao, Chen Shanshan, Zhang Yuqiao, Cao Yi, Yao Tingting, Chen Chunlin, Ye Hengqiang, Ma Xiu-Liang
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016, Shenyang, China.
School of Materials Science and Engineering, University of Science and Technology of China, 110016, Shenyang, China.
Nat Commun. 2024 Jul 19;15(1):6099. doi: 10.1038/s41467-024-50431-9.
Domain walls affect significantly ferroelectric and magnetic properties of magnetoelectric multiferroics. The stereotype is that the ferroelectric polarization will reduce at the domain walls due to the incomplete shielding of depolarization field or the effects of gradient energy. By combining transmission electron microscopy and first-principles calculations, we demonstrate that the ferroelectric polarization of tail-to-tail 180° domain walls in ε-FeO is regulated by the bound charge density. A huge enhancement (43%) of ferroelectric polarization is observed in the type I domain wall with a low bound charge density, while the ferroelectric polarization is reduced to almost zero at the type II domain wall with a high bound charge density. The magnetic coupling across the type I and type II ferroelectric domain walls are antiferromagnetic and ferromagnetic, respectively. Revealing mechanisms for enhancing ferroelectric polarization and magnetic behaviors at ferroelectric domain walls may promote the fundamental research and potential applications of magnetoelectric multiferroics.
畴壁对磁电多铁性材料的铁电和磁性性质有显著影响。通常的观点是，由于退极化场屏蔽不完全或梯度能的影响，铁电极化在畴壁处会降低。通过结合透射电子显微镜和第一性原理计算，我们证明了ε-FeO中尾对尾180°畴壁的铁电极化受束缚电荷密度调控。在束缚电荷密度低的I型畴壁中观察到铁电极化大幅增强（43%），而在束缚电荷密度高的II型畴壁中，铁电极化几乎降至零。跨越I型和II型铁电畴壁的磁耦合分别为反铁磁和铁磁。揭示铁电畴壁处增强铁电极化和磁行为的机制可能会推动磁电多铁性材料的基础研究和潜在应用。
