Wu Shuxiang, He Zhihao, Gu Minghui, Ren Lizhu, Li Jibin, Deng Bo, Wang Di, Guo Xinhao, Li Wanjiong, Chen Mingyi, Chen Yijun, Meng Meng, Ye Quanlin, Shen Bing, Chen Xinman, Guo Jiandong, Xing Guozhong, Sou Iam Keong, Li Shuwei
School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China.
Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, 999077, China.
Nat Commun. 2024 Dec 30;15(1):10765. doi: 10.1038/s41467-024-54936-1.
The discovery of ferromagnetism in van der Waals (vdW) materials has enriched the understanding of two-dimensional (2D) magnetic orders and opened new avenues for fundamental physics research and next generation spintronics. However, achieving ferromagnetic order at room temperature, along with strong perpendicular magnetic anisotropy, remains a significant challenge. In this work, we report wafer-scale growth of vdW ferromagnet FeGaTe using molecular beam epitaxy. The epitaxial FeGaTe films exhibit robust ferromagnetism, exemplified by high Curie temperature (T = 420 K) and large perpendicular magnetic anisotropy (PMA) constant K = 6.7 × 10J/m at 300 K for nine-unit-cell film. Notably, the ferromagnetic order is preserved even in the one-unit-cell film with T reaching 345 K, benefiting from the strong PMA (K = 1.8×10J/m at 300 K). In comparison to exfoliated FeGaTe flakes, our epitaxial films with the same thickness show the significant enhancement of T, which could be ascribed to the tensile strain effect from the substrate. The successful realization of wafer-scale ferromagnetic FeGaTe films with T far above room temperature represents a substantial advancement (in some aspects or some fields, e.g. material science), paving the way for the development of 2D magnet-based spintronic devices.
范德华（vdW）材料中铁磁性的发现丰富了对二维（2D）磁序的理解，并为基础物理研究和下一代自旋电子学开辟了新途径。然而，在室温下实现铁磁序以及强垂直磁各向异性仍然是一项重大挑战。在这项工作中，我们报道了使用分子束外延技术在晶圆级生长vdW铁磁体FeGaTe。外延FeGaTe薄膜表现出稳健的铁磁性，以九个晶胞薄膜在300 K时的高居里温度（T = 420 K）和大垂直磁各向异性（PMA）常数K = 6.7×10 J/m为例。值得注意的是，即使在单胞薄膜中，铁磁序也得以保留，T达到345 K，这得益于强PMA（300 K时K = 1.8×10 J/m）。与剥离的FeGaTe薄片相比，我们相同厚度的外延薄膜显示出T的显著提高，这可归因于衬底的拉伸应变效应。成功实现室温以上T的晶圆级铁磁FeGaTe薄膜代表了（在某些方面或某些领域，例如材料科学）的重大进展，为基于二维磁体的自旋电子器件的发展铺平了道路。
