Elastic properties of graphene flakes: Boundary effects and lattice vibrations

S. Bera, A. Arnold, F. Evers, R. Narayanan, and P. Wölfle
Phys. Rev. B 82, 195445 – Published 30 November 2010

Abstract

We present a phenomenological theory together with explicit calculations of the electronic ground-state energy, the surface contribution, and the elastic constants (“Lamé parameters,” i.e., Poisson ratio, Young’s modulus) of graphene flakes on the level of the density-functional theory employing different standard functionals. We observe that the Lamé parameters in small flakes can differ from the bulk values by 30% for hydrogenated zigzag edges. The change results from the edge of the flake that compresses the interior. When including the vibrational zero-point motion, we detect a decrease in the bending rigidity, κ, by 26%. The vibrational frequencies flow with growing N due to the release of the edge-induced compression. We calculate the corresponding Grüneisen parameters and find good agreement with previous authors.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
7 More
  • Received 23 March 2010

DOI:https://doi.org/10.1103/PhysRevB.82.195445

©2010 American Physical Society

Authors & Affiliations

S. Bera1,2, A. Arnold2, F. Evers1,2, R. Narayanan3, and P. Wölfle1,2

  • 1Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
  • 2Institut für Nanotechnologie, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
  • 3Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 82, Iss. 19 — 15 November 2010

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×