title: Reversible loss of Bernal stacking during the deformation of few-layer graphene in nanocomposites.
abstract: The deformation of nanocomposites containing graphene flakes with different numbers of layers has been investigated with the use of Raman spectroscopy. It has been found that there is a shift of the 2D band to lower wavenumber and that the rate of band shift per unit strain tends to decrease as the number of graphene layers increases. It has been demonstrated that band broadening takes place during tensile deformation for mono- and bilayer graphene but that band narrowing occurs when the number of graphene layers is more than two. It is also found that the characteristic asymmetric shape of the 2D Raman band for the graphene with three or more layers changes to a symmetrical shape above about 0.4% strain and that it reverts to an asymmetric shape on unloading. This change in Raman band shape and width has been interpreted as being due to a reversible loss of Bernal stacking in the few-layer graphene during deformation. It has been shown that the elastic strain energy released from the unloading of the inner graphene layers in the few-layer material (~0.2 meV/atom) is similar to the accepted value of the stacking fault energies of graphite and few layer graphene. It is further shown that this loss of Bernal stacking can be accommodated by the formation of arrays of partial dislocations and stacking faults on the basal plane. The effect of the reversible loss of Bernal stacking upon the electronic structure of few-layer graphene and the possibility of using it to modify the electronic structure of few-layer graphene are discussed.
authors.affiliation: Materials Science Centre, School of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Lei
authors.initials: L
authors.lastname: Gong
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Young
authors.forename: Ian A
authors.initials: IA
authors.lastname: Kinloch
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Haigh
authors.forename: Jamie H
authors.initials: JH
authors.lastname: Warner
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Hinks
authors.forename: Ziwei
authors.initials: Z
authors.lastname: Xu
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Ding
authors.forename: Ibtsam
authors.initials: I
authors.lastname: Riaz
authors.forename: Rashid
authors.initials: R
authors.lastname: Jalil
authors.forename: Kostya S
authors.initials: KS
authors.lastname: Novoselov
references.citation: Phys Rev Lett. 2010 Apr 30;104(17):176404
references.pmid: 20482122
references.citation: Nano Lett. 2010 Jan;10(1):6-10
references.pmid: 19928908
references.citation: Proc Natl Acad Sci U S A. 2005 Jul 26;102(30):10451-3
references.pmid: 16027370
references.citation: Phys Rev Lett. 2006 Nov 3;97(18):187401
references.pmid: 17155573
references.citation: Nano Lett. 2010 Oct 13;10(10):4074-9
references.pmid: 20735024
references.citation: J Microsc. 2011 Nov;244(2):152-8
references.pmid: 21711460
references.citation: ACS Nano. 2011 Dec 27;5(12):9984-91
references.pmid: 22122696
references.citation: ACS Nano. 2011 Nov 22;5(11):8760-8
references.pmid: 21962035
references.citation: Small. 2010 Jan;6(2):195-200
references.pmid: 19908274
references.citation: Proc Natl Acad Sci U S A. 2009 May 5;106(18):7304-8
references.pmid: 19380746
references.citation: Nature. 2005 Nov 10;438(7065):197-200
references.pmid: 16281030
references.citation: Phys Rev Lett. 2006 Mar 3;96(8):086805
references.pmid: 16606214
references.citation: Adv Mater. 2010 Jun 25;22(24):2694-7
references.pmid: 20473982
references.citation: Science. 2004 Oct 22;306(5696):666-9
references.pmid: 15499015
references.citation: ACS Nano. 2011 Apr 26;5(4):3079-84
references.pmid: 21395299
references.citation: ACS Nano. 2011 Mar 22;5(3):2231-9
references.pmid: 21319849
references.citation: Phys Rev Lett. 2011 Mar 25;106(12):126802
references.pmid: 21517338
references.citation: ACS Nano. 2012 Mar 27;6(3):2086-95
references.pmid: 22364317
references.citation: Nano Lett. 2012 Feb 8;12(2):687-93
references.pmid: 22165946
references.citation: Nano Lett. 2012 Mar 14;12(3):1609-15
references.pmid: 22329410
references.citation: Nanoscale Res Lett. 2011 Jul 29;6:478
references.pmid: 21801347
references.citation: Nat Mater. 2012 Feb 05;11(4):294-300
references.pmid: 22306771
references.citation: Nat Mater. 2007 Mar;6(3):183-91
references.pmid: 17330084
references.citation: Nano Lett. 2011 Jan 12;11(1):164-9
references.pmid: 21121668
references.citation: Nano Lett. 2009 Jan;9(1):102-6
references.pmid: 19072722
references.citation: Science. 2008 Jul 18;321(5887):385-8
references.pmid: 18635798