title: Dynamics of atomic stick-slip friction examined with atomic force microscopy and atomistic simulations at overlapping speeds.
abstract: Atomic force microscopy (AFM) and atomistic simulations of atomic friction with silicon oxide tips sliding on Au(111) are conducted at overlapping speeds. Experimental data unambiguously reveal a stick-slip friction plateau above a critical scanning speed, in agreement with the thermally activated Prandtl-Tomlinson (PTT) model. However, friction in experiments is larger than in simulations. PTT energetic parameters for the two are comparable, with minor differences attributable to the contact area's influence on the barrier to slip. Recognizing that the attempt frequency may be determined by thermal vibrations of the larger AFM tip mass or instrument noise fully resolves the discrepancy. Thus, atomic stick-slip is well described by the PTT model if sources of slip-assisting energy are accounted for.
authors.affiliation: Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 220 South 33rd Street, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Xin-Z
authors.initials: XZ
authors.lastname: Liu
authors.affiliation: School of Engineering, University of California Merced, 5200 North Lake Road, Merced, California 95343, USA.
authors.forename: Zhijiang
authors.initials: Z
authors.lastname: Ye
authors.affiliation: Department of Mechanical and Manufacturing Engineering, University of Calgary, 40 Research Place NW, Calgary, Alberta T2L 1Y6 Canada.
authors.forename: Yalin
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Mechanical Engineering, University of Akron, 302 Buchtel Common, Akron, Ohio, 44325 USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Egberts
authors.affiliation: Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 220 South 33rd Street, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Carpick
authors.affiliation: School of Engineering, University of California Merced, 5200 North Lake Road, Merced, California 95343, USA.
authors.forename: Ashlie
authors.initials: A
authors.lastname: Martini