Two-dimensional itinerant ferromagnetism in atomically thin Fe3GeTe2
Two-dimensional itinerant ferromagnetism in atomically thin Fe3GeTe2
复制标题
DOI：
10.1038/s41563-018-0149-7
复制
发表时间：
2018-09-01
期刊：
影响因子：
41.2
通讯作者：
Xu, Xiaodong
中科院分区：
文献类型：
--
作者：
Fei, Zaiyao;Huang, Bevin;Xu, Xiaodong
范德华 (vdW) 晶体中固有二维 (2D) 铁磁性的发现为研究基本二维磁性和采用局域自旋的器件提供了一个有趣的领域 (1-4)。然而，表现出固有二维流动磁性的可剥离 vdW 材料仍然难以捉摸。在这里，我们证明了 Fe3GeTe2 (FGT) 是一种可剥离的 vdW 磁体，当减薄到单层时，它表现出强大的二维铁磁性和强垂直各向异性。层数相关的研究揭示了厚度小于 4 nm（五层）的伊辛铁磁性从 3D 到 2D 的交叉，同时单层的居里温度 (T-c) 从 207 K 快速下降到 130 K。对于厚度大于 15 nm 的 FGT 薄片，在中间温度范围内会出现明显的磁性行为，我们表明这是由于迷宫磁畴图案的形成所致。我们的工作介绍了一种原子薄铁磁金属，可用于研究可控二维巡回铁磁性和工程自旋电子 vdW 异质结构 (5)。
Discoveries of intrinsic two-dimensional (2D) ferromagnetism in van der Waals (vdW) crystals provide an interesting arena for studying fundamental 2D magnetism and devices that employ localized spins(1-4). However, an exfoliable vdW material that exhibits intrinsic 2D itinerant magnetism remains elusive. Here we demonstrate that Fe3GeTe2 (FGT), an exfoliable vdW magnet, exhibits robust 2D ferromagnetism with strong perpendicular anisotropy when thinned down to a monolayer. Layer-number-dependent studies reveal a crossover from 3D to 2D Ising ferromagnetism for thicknesses less than 4 nm (five layers), accompanied by a fast drop of the Curie temperature (T-c) from 207 K to 130 K in the monolayer. For FGT flakes thicker than similar to 15 nm, a distinct magnetic behaviour emerges in an intermediate temperature range, which we show is due to the formation of labyrinthine domain patterns. Our work introduces an atomically thin ferromagnetic metal that could be useful for the study of controllable 2D itinerant ferromagnetism and for engineering spintronic vdW heterostructures(5).