Fig. 2: Friction enhancement caused by atomic defects.
From: Ultrafast dynamics of electronic friction energy dissipation in defective semiconductor monolayer
a High-angle annular dark field (HAADF) STEM images of monolayer WS2 after tip sliding. Sulfur vacancies are marked by yellow circles. The sliding loads are 500, 1000, 2000, and 3000 nN respectively. b Corresponding friction force maps under a constant normal force of 50 nN. c Relationship curve between friction force and normal force of monolayer WS2 in varying defect densities. Error bars represent the standard deviation of the data based on 256 data points. d Friction coefficient diagram under different defect densities is calculated from the line slope in c. The error bar is obtained by linearly fitting the friction coefficient. Source data of c and d is provided as a Source Data file.
