First-principles determination of static potential energy surfaces for atomic friction in MoS2 and MoO3

Using first-principles electronic-structure calculations of static potential energy surfaces, we investigate the atomic-scale energetic barriers encountered during sliding at MoS2 (001) and MoO3 (001) surfaces and at the MoS2/MoO3 interface. The results indicate the minimum energy path to sliding and provide an upper bound to the force that must be applied in order to initiate sliding. The results further suggest that the lowest energy pathway is to slide MoO3 over MoS2 along the channel direction formed by S atoms at the sliding interface, and the highest energy pathway involves MoO3 (001) interlayer sliding, which is consistent with the results of experimental microscopic investigations of similar crystalline interfaces.