Observation of robust superlubricity of MoS2 on Au(111) in ultrahigh vacuum

Atomic Friction Processes of Two-Dimensional Materials

“…It is attributed to the relative rigidity of the moiré superlattice originating from a natural misfit between MoS 2 and the gold surface. The disappearance of the “strengthening” effect (Figure c) confirms the strong suppression of both local in-plane and out-of-plane deformation of the MoS 2 layer scanned by an AFM probe . The preparation and friction measurement of the MoS 2 surface under UHV conditions are important for the experimental findings to exclude potential contaminations.…”

“…71 It was confirmed by another FFM experiment revealing pronounced adhesion and higher sliding friction between MoS 2 and the Au-coated tip, in contrast to the silicon tip. 72 The friction force measurements of the MoS 2 /Au(111) system were carried out, revealing apparent independence of friction on load with a relatively large moirésize of 3.3 nm, 70 in contrast to the previously reported moirélevel friction at the ridge leading to a highly dissipated regime. The puckering effect is not observable when analyzing the corresponding lateral force trace and retrace (Figure 4).…”

“… 69 The influence of the strength of interfacial interactions on moiré friction should be investigated. Song et al prepared MoS 2 film on Au(111) surface under UHV conditions 70 to exclude the contaminants. 45 Relatively strong adhesion has been predicted by previous DFT calculations for the MoS 2 /Au(111) system.…”

“…The disappearance of the “strengthening” effect ( Figure 4 c) confirms the strong suppression of both local in-plane and out-of-plane deformation of the MoS 2 layer scanned by an AFM probe. 70 The preparation and friction measurement of the MoS 2 surface under UHV conditions are important for the experimental findings to exclude potential contaminations. This paves the way to control moiré friction by varying the strength of interaction of 2D atomic layer with the underlying substrate.…”

Long-Term Stable Superlubricity Coatings Enabled by the Interaction between the Polydimethylsiloxane Brush and Silicone Oil

“…Since it can decrease resistance and save energy, materials with superlubricity are of tremendous importance from the perspective of saving energy and protecting the environment. , In recent decades, the realm of exploring superlubricity in both solids and liquids has garnered significant interest in the fields of fundamental science and engineering, thus, witnessing significant strides. For solid lubrication materials, such as MoS 2 , graphene, hexagonal boron nitride, and diamond-like amorphous carbon coatings, the realization of superlubrication required some strict conditions such as the incommensurate contact state, the protection of inert gases, or an ultrahigh vacuum condition, which limited its application. – …”