Invited Paper SE+NS-MoM3
Interface Phenomena in Nanostructured Thin Films and Coatings

Monday, October 29, 2012, 9:00 am, Room 22

The properties of nanostructured thin films and coatings are strongly influenced by the structure of internal interfaces. Thus, the understanding of the formation of the interfaces and the knowledge of the relationship between the microstructure and the materials properties are the first steps in designing nanostructured materials with tailored properties. This talk will focus on partially coherent interfaces between adjacent crystalline phases in nanostructured thin films and coatings, discussing the mechanisms of their formation, showing the capabilities of experimental methods for microstructure analysis to detect these interfaces and to describe their structure on the atomic scale, and recognizing the influence of the interfaces on the materials properties.

The interface phenomena and their impact on hardness and thermal stability of nanostructured thin films and coatings will be illustrated on physical vapor deposited transition metal nitrides containing aluminum and/or silicon, where the internal interfaces form as a consequence of the decomposition of metastable supersaturated solid solutions. It will be shown how the local fluctuations of the chemical composition arising during the deposition process and the local strain fields resulting from differences in the interatomic distances at partially coherent interfaces influence the decomposition process and the stability of the metastable phases.

The description and quantification of the interface phenomena on atomic scale would be impossible without a detailed microstructure analysis that is required to reveal the constitution of the nanostructured materials, to reproduce the structure of the internal interfaces and to assess the coherence of the interfaces. Hence, this talk will also recapitulate the recent developments in the microstructure analytics on the nanostructured thin films and coatings.