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O: Fachverband Oberflächenphysik
O 84: Focussed session: Frontiers of electronic structure theory: Strong correlations from first principles VI (jointly with TT)
O 84.4: Vortrag
Freitag, 30. März 2012, 11:30–11:45, HE 101
Internal elasticity of graphene-based systems — •Pasquale Pavone1,2, Rostam Golesorkhtabar1,2, Jürgen Spitaler1,2, and Claudia Ambrosch-Draxl1 — 1Chair of Atomistic Modelling and Design of Materials, University of Leoben, Austria — 2Materials Center Leoben Forschung Gmbh, Leoben, Austria
When a crystal undergoes a strain deformation, the lower symmetry of the deformed structure may allow for internal relaxations of atomic positions which do not follow the macroscopic applied strain. These relaxations can be described introducing the concept of internal-strain tensor [1], which relates the local deformation to the macroscopic strain. In this work, we present a first-principles calculation of the linear and non linear internal-strain tensors for a monolayer graphene as well as for hexagonal graphite. In order to analyze the relevance of the internal relaxation for hexagonal structures, results are also compared with ab-initio data for the cubic diamond phase. Calculations are performed using the pseudo-potential density-functional-theory code Quantum ESPRESSO [2] and both the local-density and generalized-gradient approximations for the exchange-correlation energy. The accuracy of the result of this investigation allows to solve some open issues arising in the literature from previous model [3] as well as ab-initio [4] calculations.
[1] C.S.G. Cousins, J. Phys.: Condens. Matter 14, 5091 (2002)
[2] P. Giannozzi et al., J. Phys. Condens. Matter 21, 395502 (2009)
[3] C.S.G. Cousins and M.I. Heggie, Phys. Rev. B 67, 024109 (2003)
[4] R. Wang et al., Physica B: Condens. Matter 405, 3501 (2010)