Low Z element based room temperature ferromagnetic materials are highly sought after for many applications. In this work, we report the development of fluorine functionalized graphene-hBN out-of-plane heterostructures (hBNCF), which possess large room temperature ferromagnetic ordering (magnetization ∼ 0.05 emu/g and coercivity ∼ 420 Oe) and exhibit T₂ relaxation enhancement (0.55 s⁻¹ found for D₂O was increased to ∼7 s⁻¹ at 1 mg/ml) in water without causing the T₁. The ferromagnetic nature of the hBNCF powder devoid of any metallic magnetic impurities was further shown by magnetic force microscopy. Layered structures of hBNCF that have an optical bandgap of ∼3.89 eV were produced using a two step method: Shear exfoliated hBN layers were modified by surface graphitisation to result into layered graphene heterostructures (hBNC), which were then functionalized with fluorine. Apparent ferromagnetic properties arise from these large scale, vertical, non-van der Waals connected, crystalline layer structures. Density functional calculations show the role of out-of-plane covalently connected BN domains and their interaction with fluorine, that causes the formation of new states in the graphitic lattice. These states exhibit a spin splitting, which contributes to the observed large magnetic ordering.

基于低 Z 元素的室温铁磁材料在许多应用中备受追捧。在这项工作中，我们报告了氟功能化石墨烯-hBN 面外异质结构 (hBNCF) 的发展，其具有较大的室温铁磁有序性（磁化强度 ∼ 0.05 emu/g 和矫顽力 ∼ 420 Oe）并表现出 T ₂弛豫增强（对于 D ₂ O发现的0.55 s ^-1 在 1 mg/ml时增加到 ~7 s ^-1），而不会导致 T ₁. 通过磁力显微镜进一步显示了不含任何金属磁性杂质的 hBNCF 粉末的铁磁性质。hBNCF 的光学带隙为~3.89 eV 的层状结构是使用两步法生产的：剪切剥离的 hBN 层通过表面石墨化进行改性，形成层状石墨烯异质结构 (hBNC)，然后用氟进行功能化。这些大尺度、垂直、非范德华连接的晶体层结构产生了明显的铁磁特性。密度泛函计算显示面外共价连接的 BN 域的作用及其与氟的相互作用，导致石墨晶格中新状态的形成。这些状态表现出自旋分裂，这有助于观察到大磁序。