Graphene nanodots with intrinsically magnetic protrusions

Michael R. Philpott, Yoshiyuki Kawazoe

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

The three step auf bau of a triangular polyaromatic protrusion attached to a larger parent hexagonal shaped graphene nanodot (GND) is described and the dichotomy between intrinsic protrusion localized magnetism and parent extended zigzag edge magnetism is explored using ab initio density functional theory calculations of spin and charge distributions and geometry. Comparison of a three ring with a ten-ring protrusion-GND establishes a pattern for the magnetization of GNDs with larger protrusions and different morphology. The magnetism of the isolated protrusions arises from the mismatch in numbers of sublattice (alternant hydrocarbon) carbon atoms. In the parent, the sublattices are equivalent providing a singlet ground state and the magnetization appears only on long zigzag edges due to exchange interactions operating in a regime of reduced coulombic interactions. We demonstrate that a small protrusion can quench the magnetism of the edge to which it is attached. Concomitantly, the adjacent edges exhibit a small magnetic enhancement, while the remote edges are unperturbed. With size the protrusion can dominate its edge and exert control over the magnetization of other edges. Different multiplicities of the parent moiety were not found. These calculations provide guidance in understanding how the magnetism changes with system shape and in designing nanodots with a specific magnetization.

Original languageEnglish
Article number064706
JournalJournal of Chemical Physics
Volume136
Issue number6
DOIs
Publication statusPublished - 2012 Feb 14

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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