Coatings and Films analyzed and optimized by Moessbauer Spectroscopy

Thin Films, multilayers and coatings are playing a steadily increasing role for most advanced technical applications and the development of new materials. For the improvement of corrosion, friction and wear properties of machine and tool surfaces, carbides and nitrides are especially interesting. Here we present the effects of pulsed laser irradiation of iron in methane atmosphere and their analysis by Moessbauer spectroscopy. The dependence of the phase formation and the resulting properties are given in relation to the laser treatment parameters, such as number of laser shots and reactive gas pressure. For example, the irradiation of pure iron in methane atmosphere at low pressures or low number of laser pulses results in the formation of an amorphous carbon surface layer and hexagonal FexC, which is more and more transformed into Fe3C cementite when increasing the number of pulses or the gas pressure. It will be demonstrated that Moessbauer spectroscopy is well suited to analyze the processing and to give valuable hints for its optimization