MODIFICATION OF CHEMICAL SURFACE-PROPERTIES BY ION-BEAM ASSISTED DEPOSITION

Ion beam assisted deposition represents a superior method for controlled modifications of surface layers and production of coatings. In addition, it is a unique tool for studying the influence of ion bombardment parameters on the quality of coatings. The chemical composition and structure of surface films and of the film/substrate interface have a strong influence on many properties of the coated system. It is demonstrated that they change considerably under ion bombardment, often under formation of compound films or separate "interphases". Auger electron depth profiling and Mossbauer spectroscopy were used for these investigations. Correlations with macroscopic properties were established by adhesion and hardness measurements. As an example for chemical applications the resistance of hard coatings against aqueous corrosion of steel was studied in relation to the composition and stoichiometry of the films. Finally a new approach for ion bombardment and ion beam assisted deposition of powder targets is presented and illustrated by an example for electrochemical applications. © 1990.