title: Tip-enhanced Raman mapping of local strain in graphene.
abstract: We demonstrate local strain measurements in graphene by using tip-enhanced Raman spectroscopy (TERS). We find that a single 5 nm particle can induce a radial strain over a lateral distance of ∼170 nm. By treating the particle as a point force on a circular membrane, we find that the strain in the radial direction (r) is ∝ r−(2 3),in agreement with force-displacement measurements conducted on suspended graphene flakes. Our results demonstrate that TERS can be used to map out static strain fields at the nanoscale, which are inaccessible using force-displacement techniques.
authors.affiliation: Institute of Optics, University of Rochester, Rochester, NY 14627, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Beams
authors.forename: Luiz Gustavo
authors.initials: LG
authors.lastname: Cançado
authors.forename: Ado
authors.initials: A
authors.lastname: Jorio
authors.forename: A Nick
authors.initials: AN
authors.lastname: Vamivakas
authors.forename: Lukas
authors.initials: L
authors.lastname: Novotny