Structure and properties of titanium doped tungsten disulfide thin films produced via the magnetron co-sputtering DC technique

Abstract

In this work, titanium doped tungsten disulfide thin films (WS2-Ti) were deposited on AISI 304 stainless-steel substrates using the magnetron co-sputtering DC technique. Films were produced with varying titanium-cathode power from 0 to 25 W. The titanium content of the WS2 structure was determined using energy dispersive spectroscopy (EDS), thereby obtaining a maximum of 10% for the sample grown at 25 W. X-ray diffraction (XRD) results indicated, for the pure sample, the presence of a hexagonal phase of high intensity on the (103) plane. However, with the addition of titanium, the WS2 crystallinity was reduced; nevertheless, when the titanium content was equal to 10%, nanocomposite formation was promoted. This effect was observed in TEM (transmission electron microscopy) images. Finally, the tribological behavior was determined using a ball on disk (BOD) test. With this method, friction coefficient curves were obtained with respect to the number of cycles, allowing the measurement of friction coefficient values of 0.1 for the pure sample and 0.15 for the sample grown at 5 W. Because of the low thickness of the samples, all of them failed during the first cycles.