title: Visualising the strain distribution in suspended two-dimensional materials under local deformation.
abstract: We demonstrate the use of combined simultaneous atomic force microscopy (AFM) and laterally resolved Raman spectroscopy to study the strain distribution around highly localised deformations in suspended two-dimensional materials. Using the AFM tip as a nanoindentation probe, we induce localised strain in suspended few-layer graphene, which we adopt as a two-dimensional membrane model system. Concurrently, we visualise the strain distribution under and around the AFM tip in situ using hyperspectral Raman mapping via the strain-dependent frequency shifts of the few-layer graphene's G and 2D Raman bands. Thereby we show how the contact of the nm-sized scanning probe tip results in a two-dimensional strain field with μm dimensions in the suspended membrane. Our combined AFM/Raman approach thus adds to the critically required instrumental toolbox towards nanoscale strain engineering of two-dimensional materials.
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: Kenan
authors.initials: K
authors.lastname: Elibol
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: Bernhard C
authors.initials: BC
authors.lastname: Bayer
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hummel
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: Jani
authors.initials: J
authors.lastname: Kotakoski
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Argentero
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: Jannik C
authors.initials: JC
authors.lastname: Meyer