AVS 60th International Symposium and Exhibition
    Graphene and Other 2D Materials Focus Topic Tuesday Sessions
       Session GR+AS+NS+SP+SS-TuA

Paper GR+AS+NS+SP+SS-TuA10
Nanoscale Tribological Characteristics of Epitaxial Graphene on SiC: The Effect of Hydrogen Intercalation

Tuesday, October 29, 2013, 5:00 pm, Room 104 B

Session: Characterization including Microscopy and Spectroscopy of 2D Materials
Presenter: S. Kwon, KAIST, Republic of Korea
Authors: S. Kwon, KAIST, Republic of Korea
J. Ko, KAIST, Republic of Korea
G.E. Yang, KRISS, Republic of Korea
W. Kim, KRISS, Republic of Korea
Y. Kim, KAIST, Republic of Korea
J.Y. Park, KAIST, Republic of Korea
Correspondent: Click to Email
Atomically-thin graphene is the ideal model system for studying nanoscale friction due to its intrinsic two-dimensional anisotropy. Here, we report the reduced nanoscale friction of epitaxial graphene on SiC, investigated with conductive-probe atomic force microscopy/friction force microscopy in ultra-high vacuum. The measured friction on a buffer layer was found to be 1/8 of that on a monolayer of epitaxial graphene. Conductive probe atomic force microscopy revealed a lower conductance on the buffer layer, compared to monolayer graphene. We associate this difference in friction with the difference in total lateral stiffness. Because bending stiffness is associated with flexural phonons in two-dimensional systems, nanoscale frictional energy should primarily dissipate through damping with the softest phonons. We investigated the influence of hydrogen intercalation on the nanoscale friction. We found that the friction decreased significantly after hydrogen intercalation, which is related to loose contact between the graphene and the substrate that results in a lower bending stiffness.