Nanotribological Properties of the h-BN/Au(111) Interface: A DFT Study

Abstract

Understanding the quantum-mechanical origins of friction forces has become increasingly important in the past decades with the advent of nanotechnology. At the nanometer scale, the universal Amontons−Coulomb laws cease to be valid, and each interface requires individual scrutiny. Because of the well-known lubricating properties of two-dimensional materials, a significant amount of research has been performed in an effort to understand interfaces they form with one another. However, the interfaces between these two-dimensional materials and metals red from a tribological point of view, important for such applications as friction force microscopy, have yet to be thoroughly investigated. In the current work, we present a detailed density functional theory investigation of the hexagonal BN/Au(111) interface. Because of a good agreement between their characteristic lengths, a high level of commensurability is achieved in a suitably constructed model between the bulk surfaces of the two materials. As a result of our calculations, we find that the corrugation in the potential energy surface and the lateral forces in this interface are low compared to other similar interfaces. The friction coefficient falls rapidly with increasing load down to 0.005 for the largest loads considered. In contrast, Au n clusters (n = 1, 4, 13, and 19) sliding on the h-BN surface exhibit much larger lateral forces, indicating strong size and edge effects. The reduction of energy corrugation in going from the Au 4 to the Au 19 cluster may already indicate a decreasing trend with increasing size even at this very small scale.

Inverse Relationship between Thickness and Wear of Fluorinated Graphene: “Thinner Is Better”

“…In order to understand the origin of interfacial interactions that affect friction and wear resistance of FG on silicon substrates, we employed density functional theory with dispersion correction (DFT-D) and estimated charge transfer and adhesion of the FG/substrate interface. − Details of DFT-D calculations are given in Figure S11 and Methods. Figure compares the charge density difference (ρ diff ) and adhesion energy (| E adh |) obtained with DFT-D calculations for 1L FG on Si–H and 1–3L FG on silica–OH.…”

First‐principles Calculations Reveal Frictional Advantage for C2N/C6N6 van der Waals Heterostructures

“…Comparing our results with that from the previously reported cases like h ‐BN/ h ‐BN and graphene/graphene homostructure (δ corr ~10 meV/atom) shows better tribological properties for C 2 N/C 6 N 6 . Only with modified surfaces like chemically decorated graphene (δ corr ~4 meV/atom) or other heterostructures like graphene/MoS 2 (δ corr ~0.046 meV/atom) or h‐BN/Au (δ corr ~0.15 meV/atom) low corrugation energy is realized [31,32,12,14,16] …”

“…computed interaction between Pd and graphite and described the microscopic mechanism for atomic force microscopy [11] . Baksi showed a decreasing trend in corrugation energy over h ‐BN as the Au cluster size increases from Au 4 to Au 19 [12] . The tribological properties are highly sensitive towards chemical modifications like oxidation or defects.…”

Atomic-Scale Superlubricity in Ti2CO2@MoS2 Layered Heterojunctions Interface: A First Principles Calculation Study

“…Lateral force ( F L ) can be calculated by the same method, and more details refer to previous literature studies. 32 The static friction coefficient is obtained according to the standard definition. …”