Atomic scale surfaces and functional coatings, thin films and interfaces (ASCI)
The research and activity domain (RAD) on surfaces (both at the atomic scale and functional), coatings, films and interfaces encompasses three aspects: processing, surface sciences, and properties determination. These three aspects cover the entire processing – structure – properties range in materials science and engineering, investigated both experimentally and theoretically. Properties investigation, and consequently implementation to the market of surfaces, interfaces, thin films and coatings composed of complex intermetallics and oxides, depends on the capacity to develop or to process them on predefined substrates with appropriate and controllable microstructure.
Dry, gas phase deposition techniques under various atmospheres including ultra high vacuum conditions are a privileged means to achieve this objective. The appropriate choice of the deposition technique will depend on numerous factors, not excluding economic and environmental ones. Physical (such as magnetron sputtering and PLD…) and chemical (such as MOCVD and ALD) vapor deposition allow processing films with the desirable elemental composition; however, direct stabilization of the targeted phases is not systematically possible. In that case, post deposition, reactive diffusion treatments are necessary. This is especially the case when the participating elements are sequentially deposited. Here, the characterisation by transmission electron microscopy and the control of the interfaces are crucial, as it will dictate the adhesion, and the often-combined chemical (e.g. corrosion resistance), physical (e.g. electrical) and mechanical (e.g. hardness) properties of the desired coating and its lifespan.
Another aspect of the RAD lies in the structural and electronic characterisation of UHV prepared/modelled intermetallic surfaces and novel (metallic to oxide) thin films. The surfaces, which exhibit generally a complex energy landscape with local exotic symmetry (five-fold for instance), are also of interest for the growth of novel nanoscale architectures and ultrathin film with unique physical and chemical properties.
Hence, the RAD covers surfaces, coating and interfaces related phenomena from atomic scale to functional thick films while catalytic properties of surfaces are treated in a dedicated RAD. With only 6% of the theoretically possible ternary intermetallic systems known to date, there is still a wealth of surfaces to be processed and investigated. Based on the targeted properties, the system selection will be experimentally and theoretically jointly driven.
RAD leader: H.R. Sharma