Room‐Temperature Macroscopic Ferromagnetism in Multilayered Graphene Oxide

• Published in: Advanced Physics Research Vol. 3; no. 5
• Main Authors: Zhang, Di, Gao, Bo, Xu, Song, Niu, Chunyao, Xu, Qun
• Format: Journal Article
• Language: English
• Published: Edinburgh John Wiley & Sons, Inc 01.05.2024; Wiley-VCH
• Subjects: Carbon dioxide; Composite materials; Electrons; Ferromagnetism; Functional groups; Graphene; Graphite; magnetic materials; Magnetic moments; Magnetic saturation; Microscopy; Oxygen; Room temperature; Self-assembly; Shear strain; Spectrum analysis; Spintronics; supercritical CO2;2D; Temperature
• ISSN: 2751-1200; 2751-1200
• DOI: 10.1002/apxr.202300092

Graphene has a long spin lifetime and hyperfine interactions, favoring its potential application as spintronics. Despite the recent discoveries of spin‐containing graphene materials, graphene‐based materials with room‐temperature macroscopic ferromagnetism are extremely rare. In this article, room‐temperature ferromagnetic amorphous graphene oxide (GO) is synthesized by introducing abundant oxygen‐containing functional groups and C defects into single‐layered graphene, followed by a self‐assembly process under supercritical CO2 (SC CO2). Such amorphous GO exhibits the highest saturation magnetization (1.71 emu g−1) and remanent magnetization (0.251 emu g−1) compared to the rest of metal‐free graphene‐based materials at room temperature. Experimental and theoretical investigations attribute such strong ferromagnetism to the bridging of the adjacent graphene layers though the out‐of‐plane oxygen‐containing groups, which leads to asymmetric lattices with large net magnetic moments. In this paper, room‐temperature ferromagnetic amorphous graphene oxide (GO) is synthesized by introducing oxygen‐containing groups and C defects into graphene followed by self‐assembly under supercritical CO2 (SC CO2). Experimental and theoretical studies attribute this strong ferromagnetism to the bridging of neighboring graphene layers through out‐of‐plane oxygen‐containing groups, resulting in an asymmetric lattice with a large net magnetic moment.