Embedding atomic cobalt into graphene lattices to activate room-temperature ferromagnetism
Wei Hu, Chao Wang, Hao Tan, Hengli Duan, Guinan Li, Na Li, Qianqian Ji, Ying Lü, Yao Wang, Zhihu Sun, Fengchun Hu, Wensheng Yan
Abstract
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 C up to ∼400 K and saturation magnetization of 0.11 emu g −1 (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 4 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 z 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.