▎ 摘　　要

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 similar to 0.05 emu/g and coercivity similar to 420 Oe) and exhibit T-2 relaxation enhancement (0.55 s(-1) found for D2O was increased to similar to 7 s(-1) at 1 mg/ml) in water without causing the T-1. 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 similar to 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. (C) 2021 Published by Elsevier Ltd.