MICROSTRUCTURE AND TRIBOLOGICAL PROPERTIES OF SPUTTERED NBTEX THIN-FILMS

Thin NbTe(x) films were deposited on steel by sputtering. Annealing wa s performed at several temperatures. Phase transition phenomena were a nalysed by X-ray diffraction (theta-2theta and grazing incidence). Dep ending on the conditions (sputtering and annealing) the structure of t he films changed from the NbTe2 (two-dimensional) to the Nb3Te4 (three -dimensional with linear channels) structural type and the intercalati on of Te or Nb atoms within the parent structures was suggested. Films were evaluated under fretting conditions at 1 Hz in a dry environment . The displacement was +/- 50 mum and the contact pressure was 300 MPa . Friction coefficients were low, ranging from 0.08 to 0.18 depending on the film structure. The classical dependence of friction coefficien t on pressure, well known for solid lubricants, was observed for NbTe2 . Thickness and annealing temperature were shown to have a major effec t on endurance.