Microwave Energy Drives “On–Off–On” Spin‐Switch Behavior in Nitrogen‐Doped Graphene

• Published in: Advanced materials (Weinheim) Vol. 31; no. 37; pp. e1902587 - n/a
• Main Authors: Zoppellaro, Giorgio, Bakandritsos, Aristides, Tuček, Jiří, Błoński, Piotr, Susi, Toma, Lazar, Petr, Bad'ura, Zdeněk, Steklý, Tomáš, Opletalová, Ariana, Otyepka, Michal, Zbořil, Radek
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-09-2019
• Subjects: Electron spin; Ferromagnetism; fluorographene; Graphene; Nitrogen; nitrogen doping; spin switch; Spin valves; spintronics; spin‐polarized states; Substrates; Switches; spin-polarized states; spin switch; spintronics; fluorographene; nitrogen doping
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201902587

The established application of graphene in organic/inorganic spin‐valve spintronic assemblies is as a spin‐transport channel for spin‐polarized electrons injected from ferromagnetic substrates. To generate and control spin injection without such substrates, the graphene backbone must be imprinted with spin‐polarized states and itinerant‐like spins. Computations suggest that such states should emerge in graphene derivatives incorporating pyridinic nitrogen. The synthesis and electronic properties of nitrogen‐doped graphene (N content: 9.8%), featuring both localized spin centers and spin‐containing sites with itinerant electron properties, are reported. This material exhibits spin‐switch behavior (on–off–on) controlled by microwave irradiation at X‐band frequency. This phenomenon may enable the creation of novel types of switches, filters, and spintronic devices using sp2‐only 2D systems.
The “on–off–on” spin‐switch process, which involves spin‐polarized unpaired electrons, emerges in nitrogen‐doped graphene material. The spin‐switch phenomenon is activated below a temperature threshold and upon application of high microwave energy density fluxes.