Zhao Zijing, Zhou Jian, Liu Luhao, Liu Nanshu, Huang Jianqi, Zhang Biao, Li Wei, Zeng Yi, Zhang Teng, Ji Wei, Yang Teng, Zhang Zhidong, Li Songlin, Hou Yanglong
School of Materials Science and Engineering, Beijing Key Laboratory for Magnetoelectric Materials and Devices, Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing 100871, China.
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
Nano Lett. 2022 Feb 9;22(3):1242-1250. doi: 10.1021/acs.nanolett.1c04403. Epub 2022 Jan 21.
Two-dimensional (2D) magnetic materials have attracted significant attention for promising applications in energy-saving logic and robust memory devices. However, most 2D magnets discovered so far typically feature drawbacks for practical applications due to low critical temperatures. Herein, we synthesize ultrathin room-temperature (RT) magnetic FeSe nanoflakes via the space-confined chemical vapor deposition method. It is found that the appropriate supply and control of Se concentration in the reaction chamber is crucial for synthesizing high-quality nonstoichiometric FeSe nanoflakes. Cryogenic electrical and magnetic characterizations reveal the emergence of spin reorientation at ∼130 K and the survival of long-range magnetic ordering up to room temperature. The RT magnetic domain structures with different thicknesses are also uncovered by magnetic force microscopy. Moreover, theoretical calculations confirm the spin configuration and metallic band structure. The outstanding characteristics exhibited by FeSe nanoflakes, including RT magnetism, spin reorientation property, and good electrical conductivity, make them a potential candidate for RT spintronics.
二维（2D）磁性材料因其在节能逻辑和稳健存储器件中的潜在应用而备受关注。然而，迄今为止发现的大多数二维磁体由于临界温度低，在实际应用中通常存在缺点。在此，我们通过空间受限化学气相沉积法合成了超薄室温（RT）磁性FeSe纳米片。研究发现，反应室中硒浓度的适当供应和控制对于合成高质量的非化学计量比FeSe纳米片至关重要。低温电学和磁学表征揭示了在约130 K时出现自旋重取向，以及长程磁有序在室温下的存续。磁力显微镜还揭示了不同厚度的室温磁畴结构。此外，理论计算证实了自旋构型和金属能带结构。FeSe纳米片表现出的优异特性，包括室温磁性、自旋重取向特性和良好的导电性，使其成为室温自旋电子学的潜在候选材料。
