Xue Wuhong, Wang Tao, Yang Huali, Zhang Huanhuan, Dai Guohong, Zhang Sheng, Yang Ruilong, Quan Zhiyong, Li Run-Wei, Tang Jin, Song Cheng, Xu Xiaohong
Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education & School of Chemistry and Materials Science of Shanxi Normal University, Taiyuan, China.
CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China.
Nat Commun. 2025 Jan 7;16(1):440. doi: 10.1038/s41467-025-55841-x.
Antivortices have potential applications in future nano-functional devices, yet the formation of isolated antivortices traditionally requires nanoscale dimensions and near-zero magnetocrystalline anisotropy, limiting their broader application. Here, we propose an approach to forming antivortices in multiferroic ε-FeO with the coalescence of misaligned grains. By leveraging misaligned crystal domains, the large magnetocrystalline anisotropy energy is counterbalanced, thereby stabilizing the ground state of the antivortex. This method overcomes the traditional difficulty of observing isolated antivortices in micron-sized samples. Stable isolated antivortices were observed in truncated triangular multiferroic ε-FeO polycrystals ranging from 2.9 to 16.7 µm. Furthermore, the unpredictability of the polarity of the core was utilized as a source of entropy for designing physically unclonable functions. Our findings expand the range of antivortex materials into the multiferroic perovskite oxides and provide a potential opportunity for ferroelectric polarization control of antivortices.
反涡旋在未来的纳米功能器件中具有潜在应用，然而传统上孤立反涡旋的形成需要纳米尺度尺寸和近零磁晶各向异性，这限制了它们的更广泛应用。在此，我们提出一种通过错位晶粒合并在多铁性ε-FeO中形成反涡旋的方法。通过利用错位的晶畴，大的磁晶各向异性能量得以平衡，从而稳定反涡旋的基态。该方法克服了在微米尺寸样品中观察孤立反涡旋的传统困难。在尺寸范围为2.9至16.7微米的截顶三角形多铁性ε-FeO多晶体中观察到了稳定的孤立反涡旋。此外，核心极性的不可预测性被用作设计物理不可克隆功能的熵源。我们的发现将反涡旋材料的范围扩展到多铁性钙钛矿氧化物，并为反涡旋的铁电极化控制提供了潜在机会。
