Embedding atomic cobalt into graphene lattices to activate room-temperature ferromagnetism.

Hu, Wei; Wang, Chao; Tan, Hao; Duan, Hengli; Li, Guinan; Li, Na; Ji, Qianqian; Lu, Ying et al. · Nat Commun · 2021

basic_science · Level V

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Abstract

Graphene is extremely promising for next-generation spintronics applications; however, realizing graphene-based room-temperature magnets remains a great challenge. Here, we demonstrate that robust room-temperature ferromagnetism with T<sub>C</sub> up to ∼400 K and saturation magnetization of 0.11 emu g<sup>-1</sup> (300 K) can be achieved in graphene by embedding isolated Co atoms with the aid of coordinated N atoms. Extensive structural characterizations show that square-planar Co-N<sub>4</sub> moieties were formed in the graphene lattices, where atomically dispersed Co atoms provide local magnetic moments. Detailed electronic structure calculations reveal that the hybridization between the d electrons of Co atoms and delocalized p<sub>z</sub> electrons of N/C atoms enhances the conduction-electron mediated long-range magnetic coupling. This work provides an effective means to induce room-temperature ferromagnetism in graphene and may open possibilities for developing graphene-based spintronics devices.