title: An improved in situ measurement of offset phase shift towards quantitative damping-measurement with AFM.
abstract: An improved approach is introduced in damping measurement with atomic force microscope (AFM) for the in situ measurement of the offset phase shift needed for determining the intrinsic mechanical damping in nanoscale materials. The offset phase shift is defined and measured at a point of zero contact force according to the deflection part of the AFM force plot. It is shown that such defined offset phase shift is independent of the type of sample material, varied from hard to relatively soft materials in this study. This improved approach allows the self-calibrated and quantitative damping measurement with AFM. The ability of dynamic mechanical analysis for the measurement of damping in isolated one-dimensional nanostructures, e.g. individual multiwalled carbon nanotubes, was demonstrated.
authors.affiliation: Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W. Green Street, Urbana, IL 61801, USA.
authors.forename: Majid
authors.initials: M
authors.lastname: Minary-Jolandan
authors.forename: Min-Feng
authors.initials: MF
authors.lastname: Yu