Sized WS2 Lamellae and their Texture Orientations Growth

The tungsten disulfide (WS2) thin films, considered as inert, non-toxic, non-corrosive lubrication that is resistant to most fuel solvents, is the best solid lubricant for general industry. In this paper, WS2 thin films were deposited on steel and silicon <110> type substrates by DC sputtering methods with optimized experimental conditions and parameters. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were employed to characterize the surface morphology and determine the geometrical size of WS2 lamellae or microtubes. The investigation showed that both SEM and AFM analysis revealed oriented WS2 crystalline lamellae on silicon substrate while they are entangled on the steel substrate. This result leads to say precociously that the WS2 thin films deposition depend on the substrate type. Moreover, using the AFM results, we could determine the average lamella (or microtube) size which has from 200 nm to 500 nm in width and from 1mm to 1.5mm in length. The EDS tool allows attaining the composition of deposited WS2 where the tungsten and the disulfide represent about 40 and 55%, respectively.