The lateral force required to move a 1D shape molecule in the direction parallel to its molecular axis is found to be about half of that required to move it sideways, due to frictional force anisotropy traced to the shape of the molecule.
Significance and Impact
The results unveil an atomic-scale frictional phenomenon that deviates from the linear relationship of friction based on contact areas between two objects. This work impacts the understanding of friction at the atomic scale.
- Sexiphenyl (6P) molecules were manipulated on a Ag(111) surface using q+AFM (at the Center for Nanoscale Materials (CNM)) and STM tips.
- DFT calculations provided electronic structure while MD simulations revealed propagation of the molecules; both utilized the CNM Carbon computer cluster.
Work was performed in part at CNM.
About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.
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