National Research Center "Kurchatov Institute" , Kurchatov Sq. 1 , Moscow 123182 , Russia.
ACS Appl Mater Interfaces. 2018 Jun 20;10(24):20767-20774. doi: 10.1021/acsami.8b04289. Epub 2018 Jun 5.
Addition of magnetism to spectacular properties of graphene may lead to novel topological states and design of spin logic devices enjoying low power consumption. A significant progress is made in defect-induced magnetism in graphene-selective elimination of p orbitals (by vacancies or adatoms) at triangular sublattices tailors graphene magnetism. Proximity to a magnetic insulator is a less invasive way, which is being actively explored now. Integration of graphene with the ferromagnetic semiconductor EuO has much to offer, especially in terms of proximity-induced spin-orbit interactions. Here, we synthesize films of EuO on graphene using reactive molecular beam epitaxy. Their quality is attested by electron and X-ray diffraction, cross-sectional electron microscopy, and Raman and magnetization measurements. Studies of electron transport reveal a magnetic transition at T ≈ 220 K, well above the Curie temperature 69 K of EuO. Up to T, the dependence R ( B) is strongly nonlinear, suggesting the presence of the anomalous Hall effect. The role of synthesis conditions is highlighted by studies of an overdoped structure. The results justify the use of the EuO/graphene system in spintronics.
向石墨烯的奇异性质中添加磁性，可能导致新颖的拓扑状态和自旋逻辑器件的设计，其具有低功耗的优势。在石墨烯中的缺陷诱导磁性方面取得了重大进展——通过空位或 adatoms 选择性地消除 p 轨道（在三角形子晶格处），从而定制了石墨烯的磁性。与磁性绝缘体接近是一种侵入性较小的方法，目前正在积极探索。将石墨烯与铁磁半导体 EuO 集成具有很大的优势，尤其是在近邻诱导的自旋轨道相互作用方面。在这里，我们使用反应分子束外延法在石墨烯上合成了 EuO 薄膜。电子和 X 射线衍射、横截面电子显微镜、拉曼和磁化率测量证明了它们的质量。电子输运研究表明，在 T ≈ 220 K 处存在一个磁转变，远高于 EuO 的居里温度 69 K。在 T 以下，R（B）的依赖关系是强烈的非线性，表明存在反常霍尔效应。通过对过掺杂结构的研究，突出了合成条件的作用。这些结果证明了 EuO/石墨烯系统在自旋电子学中的应用是合理的。
