Composition study of electrodeposited fe-w coatings using 57fe mössbauer spectroscopy

Lately the interest in tungsten and iron group metal (Me-W) alloys has grown because of enhanced electric, magnetic, tribological and mechanical properties of these binary alloys. Such alloy coatings could be a good alternative for replacing hard chromium coatings widely used in engineering industry. Also, they show favorable magnetic properties for micro/nano-electromechanical system (MEMS/NEMS) applications. In the past making of iron-tungsten (Fe-W) coatings by electrodeposition were not giving the desired results compared to cobalt-tungsten (Co-W) and nickel-tungsten (Ni-W) coatings electrodeposition. Nowadays the improvement of iron-tungsten coating deposition are of interest, because of enviromental issues cobalt and nickel use is discouraged. Electrodeposition is a simple and cheap thin film producing technique. One can control the coatings composition, by fine tuning of deposition parameters. Mössbauer spectroscopy is a nondestructive and very precise method, which provides information about the structure, composition, magnetic and electrical properties of the samples. The main tasks of this work is studying the composition of electrodeposited Fe-W coatings using 57Fe Mössbauer spectroscopy, evaluating compound concentracions in the coatings and material properties, for possible coatings application in the industry. Main conclusions are: 1. As seen from Mössbauer spectra, coatings with tungsten concentration varying from 5 at.% to 16 at.%, contain a-Fe, Fe(W), Fe2W and W(Fe) compounds. 2. When the d.c. is