A novel design by constructing MoS2/WS2 multilayer film doped with tantalum toward superior friction performance in multiple environment

Transition metal dichalcogenides (TMDs) are easily oxidized in the humid atmosphere, leading to a decrease in their lubricating properties and limiting their application. In this study, a MoS2/WS2 multilayer film doped with tantalum (MoS2/WS2-Ta) is fabricated by magnetron sputtering to improve the corrosion and oxidation resistance of TMDs. Results show that doping of Ta makes the structure of the MoS2/WS2 multilayer film more compact, and the MoS2 and WS2 crystals exhibit a stronger (0002) preferred orientation than that of un-doped sample. Such compact structure and (0002) preferred orientation of MoS2/WS2-Ta can realize a high corrosion resistance, i.e., a more positive corrosion potential and a lower corrosion current density in comparison with the MoS2/WS2 multilayer. Furthermore, the friction properties of MoS2/WS2 multilayer film doped with 1.1 at% of Ta are improved remarkably under both of high temperature (370 °C in air) and vacuum conditions, the result is attributed to its high mechanical properties and (0002) preferred orientation. In a word, the combination of multilayer structure and doping of Ta into the films is a promising approach to accurately design the TMDs toward a wide temperature range and environmentally adaptive lubricants.