Ferromagnetism in two-dimensional black phosphorus induced by phthalocyanine cobalt

Two-dimensional (2D) magnets have been the recent research focus due to their potential to meet requirements of continuous miniaturization of spintronic devices. However, very few intrinsic 2D ferromagnetic materials, in particular room-temperature magnets, have been demonstrated because of spin fluctuations and disturbed superexchange caused by the dimensional reduction. Herein, a synchronous ultrasonic exfoliation and doping method is proposed to fabricate ferromagnetic 2D black phosphorus (BP) through the adsorption of phthalocyanine cobalt (CoPc). The electron transfer from BP to CoPc is confirmed by X-ray photoelectron spectroscopy, which is believed to be responsible for the ferromagnetic ground state in as-doped BP (Co-BP) with a saturation magnetization of 0.18 emu g−1. The density functional theory calculations well-support the charge transfer and the origin of ferromagnetism in Co-BP. In addition, the electron transfer results in the restricted activity of lone pair electrons, which might improve the antioxidant capacity of BP. Our study shed light on room-temperature ferromagnetism in 2D materials.