Spin dynamics and relaxation in graphene nanoribbons: Electron spin resonance probing

Singamaneni S. Rao, Andre Stesmans, Johan Van Tol, Dmitry V. Kosynkin, A. Higginbotham-Duque, Wei Lu, Alexander Sinitskii, James M. Tour

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

Here we report the results of a multifrequency (∼9, 20, 34, 239.2, and 336 GHz) variable-temperature continuous wave (cw) and X-band (∼9 GHz) pulse electron spin resonance (ESR) measurement performed at cryogenic temperatures on potassium split graphene nanoribbons (GNRs). Important experimental findings include the following: (a) The multifrequency cw ESR data infer the presence of only carbon-related paramagnetic nonbonding states, at any measured temperature, with the g value independent of microwave frequency and temperature. (b) A linear broadening of the ESR signal as a function of microwave frequency is noticed. The observed linear frequency dependence of ESR signal width points to a distribution of g factors causing the non-Lorentzian line shape, and the g broadening contribution is found to be very small. (c) The ESR process is found to be characterized by slow and fast components, whose temperature dependences could be well described by a tunneling level state model. This work not only could help in advancing the present fundamental understanding on the edge spin (or magnetic)-based properties of GNRs but also pave the way to GNR-based spin devices.

Original languageEnglish (US)
Pages (from-to)7615-7623
Number of pages9
JournalACS Nano
Volume6
Issue number9
DOIs
StatePublished - Sep 25 2012

Keywords

  • edge spin
  • electron spin relaxation rate
  • electron spin resonance
  • graphene nanoribbons
  • tunneling level states

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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    Rao, S. S., Stesmans, A., Van Tol, J., Kosynkin, D. V., Higginbotham-Duque, A., Lu, W., Sinitskii, A., & Tour, J. M. (2012). Spin dynamics and relaxation in graphene nanoribbons: Electron spin resonance probing. ACS Nano, 6(9), 7615-7623. https://doi.org/10.1021/nn302745x