Temperature-dependent negative friction coefficients in superlubric molybdenum disulfide thin films

Abstract

We obtain resistance characteristics for molybdenum disulfide and temperature-dependent coefficient of friction (COF) : 0.0005 which could be a superlubricating state for molybdenum disulfide coatings or thin films. Considering molybdenum disulfide lubrication we adopt the transition-state approach to calculate the temperature-dependent friction behavior. We have performed intensive calibrations via verified models considering previous experimental friction tests on some thin-solid-film samples which measured the COF in 4.2 K, 77 K and room temperature conditions to accommodate the actual working condition. To improve the performance of molybdenum disulfide we predict its better COF (=0.0005 via fine tuning of the microscopic activation volume) which could be a superlubricating state (COF <0.001) for molybdenum disulfide thin films. Our results also have negative friction coefficients for superlubricity.