Nanoscale sliding friction versus commensuration ratio: Molecular dynamics simulations

Abstract

The pioneer work of Krim and Widom ͓Phys. Rev. B 38, 12184 ͑1988͔͒ unveiled the origin of the viscous nature of friction at the atomic scale. This generated extensive experimental and theoretical activity. However, fundamental questions remain open like the relation between sliding friction and the topology of the substrate, as well as the dependence on the temperature of the contact surface. Here we present results, obtained using molecular dynamics, for the phononic friction coefficient ͑ ph ͒ for a one-dimensional model of an adsorbatesubstrate interface. Different commensuration relations between adsorbate and substrate are investigated as well as the temperature dependence of ph . In all the cases we studied ph depends quadratically on the substrate corrugation amplitude, but is a nontrivial function of the commensuration ratio between substrate and adsorbate. The most striking result is a deep and wide region of small values of ph for substrate-adsorbate commensuration ratios between Ϸ0.65 and 0.9. Our results shed some light on contradictory results for the relative size of phononic and electronic friction found in the literature.

Single-file mobility of water-like fluid in a generalized Frenkel-Kontorova model

“…Therefore, it is natural to assumed that the topological influence in the mobility is represented by the second term of equation 6: cu n 0 , where the average value of n obtained from the best fit is equal to 1.9 ± 0.3. It is worth noticing that a number of previous analytical and numerical works report a quadratic behavior of the friction with the corrugation amplitude: for fluid on surface, 37,38,48,49 for a fluid slab confined between parallel solid walls, 56 and for TIP3P water confined in carbon nanotubes. 18 The central quantity in our study is the mobility, B, of the particles chain, which is defined as the inverse of the friction coefficient η: B = η −1 .…”

“…36,47 From theoretical perspective almost all work was address by molecular dynamics simulation using a generalized Frenkel-Kotorova (FK) model as a paradigm. [37][38][39]48,49 Our aim in this work is to study the relation between confined water mobility and the CNT topology. To do this, we performed molecular dynamics simulations using a generalized Frenkel-Kontorova model.…”

Advances in atomic-scale tribological mechanisms of solid interfaces

“…Finally, the abrupt change in the sliding friction at the superconductor transition observed by Dayo et al [57] provided additional support to the viewpoint of Liebsch et al, showing that the electronic friction is of the same order of magnitude as the phononic one. Torres et al [58] adopted a one-dimensional model of an adsorbate-substrate interface, shown as The adsorbate-substrate potential U(x) is a periodic potential,…”

Evaluating the friction of rotary joints in molecular machines

“…(1) describes a stochastic process [23] and numerical integration [23,29] allows sampling solutions to this equation. This stochastic process is the rotational analog of a similar model applied to friction associated with linear motion [50,62].…”