Anisotropy effects and friction maps in the framework of the 2d PT model

Abstract

We present a series of numerical simulations on the friction-anisotropy behavior and stick-slip dynamics of a point mass in the framework of a 2d Prandtl-Tomlinson model. Results for three representative surface lattice are shown: square, hexagonal and honeycomb. Curves for scan angle dependence of static friction force, and kinetic one at T = 0 K and T = 300 K are shown. Friction force maps are computed at different directions.

High-resolution imaging of (100) kyanite surfaces using friction force microscopy in water

“…It is quite noticeable that the average values of the friction forces are similar in the two directions despite the different resolution obtained in the FFM maps. While similar friction coefficients indicate comparable tip-surface interactions along the [001] and [010] directions, the different resolution obtained can be related to differences in tip configuration and tip trajectories when the scan is performed along such directions [21].…”

Comparative Study of Dimensionality and Symmetry Breaking on Nanoscale Friction in the Prandtl–Tomlinson Model with Varying Effective Stiffness

“…Based on the above, the presence of the solvent appears to affect the effective contact stiffness through the applied load (in addition to the known impact of the load on the amplitude of the interaction energy). We chose to focus on data that were collected at room temperature, at a single constant scanning velocity, such that the amplitude of the corrugation interaction potential and the effective stiffness can be affected by effects of symmetry and dimensionality [13,[25][26][27][30][31][32][33] through the applied normal load [26,33,42,43]. Consequently, the 1D interpretation of 2D motion of the tip, or some deviation from the symmetry of the sine periodic interaction energy ascribed by the PT model, can potentially influence the behaviors of U 0 and K eff .…”

“…We extended the simulation for 2D PT model, using the approach introduced by Hölscher et al [25], which proved highly useful in describing FFM on alkali halide surfaces [30,31]: Now, in addition to Eq. (1) the dynamics is now coupled to another equivalent equation for the y-coordinate, where…”

“…During a scan, the tip bends and releases with respect to its position along the atomic-scale periodicity of the sample (for ordered surfaces), and produces a stick-slip pattern in the lateral force signal. Studies on nanoscale friction have shown that several properties influence this dynamics, such as contact area [4][5][6][7][8][9], sliding velocity [10][11][12][13][14][15][16], temperature [11,[17][18][19][20][21][22][23], anisotropy, symmetry and dimensionality [13,[24][25][26][27][28][29][30][31][32][33], and the applied normal load [4,5,23,26,[33][34][35][36][37][38][39][40][41][42][43].…”

Optical-assistant characterization of friction anisotropy properties of single-crystal graphene domains

“…The motions of the ball can reveal mechanical vibration of the tip caused by the asperities of the surface. With the model and the later extended model [32], many phenomena, such as friction force pattern [33], thermal activation [34], superlubricity [35], and friction anisotropy [36], have been analyzed theoretically. These obtained achievements have not only bridged the gap between theory and experiment, but also paved an avenue for further implementation of the model.…”