About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
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Advances and Discoveries in Non-equilibrium Driven Nanomaterials and Thin Films
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Presentation Title |
Magnetism in Graphene Nanoribbons |
Author(s) |
Srinivasa Rao Singamaneni |
On-Site Speaker (Planned) |
Srinivasa Rao Singamaneni |
Abstract Scope |
Two types of graphene nanoribbons: (a) potassium-split graphene nanoribbons (GNRs), and (b) oxidative unzipped and chemically converted graphene nanoribbons (CCGNRs) were investigated for their magnetic properties. The two types of ribbons possess remarkably different magnetic properties. While a low-temperature ferromagnet-like feature is observed in both types of ribbons, such room-temperature feature persists only in potassium-split ribbons. The GNRs show negative exchange bias, but the CCGNRs exhibit a “positive exchange bias”. Electron spin resonance measurements suggest that the carbon-related defects may be responsible for the observed magnetic behavior. Furthermore, information on the proton hyperfine coupling strength has been obtained from hyperfine sublevel correlation experiments performed on the GNRs. Electron spin resonance finds no evidence for the presence of potassium (cluster) related signals, pointing to the intrinsic magnetic nature of the ribbons. Our combined experimental results may indicate the coexistence of ferromagnetic clusters with antiferromagnetic regions leading to disordered magnetic phase. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |