skip to main content

SciTech ConnectSciTech Connect

Title: Point defect weakened thermal contraction in monolayer graphene

We investigate the thermal expansion behaviors of monolayer graphene and three configurations of graphene with point defects, namely the replacement of one carbon atom with a boron or nitrogen atom, or of two neighboring carbon atoms by boron-nitrogen atoms, based on calculations using first-principles density functional theory. It is found that the thermal contraction of monolayer graphene is significantly decreased by point defects. Moreover, the corresponding temperature for negative linear thermal expansion coefficient with the maximum absolute value is reduced. The cause is determined to be point defects that enhance the mechanical strength of graphene and then reduce the amplitude and phonon frequency of the out-of-plane acoustic vibration mode. Such defect weakening of graphene thermal contraction will be useful in nanotechnology to diminish the mismatching or strain between the graphene and its substrate.
Authors:
 [1] ;  [2] ;  [2] ;  [1] ;  [3]
  1. Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (China)
  2. (China)
  3. Department of Physics, University of Science and Technology of China, Hefei (China)
Publication Date:
OSTI Identifier:
22420037
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATOMS; BORON; CONTRACTION; DEFECTS; DENSITY FUNCTIONAL METHOD; GRAPHENE; NITROGEN; OSCILLATION MODES; PHONONS; POINT DEFECTS; SUBSTRATES; THERMAL EXPANSION