I aim to achieve a fundamental understanding of the atomistic kinetic pathways responsible for nanostructure formation and to explore the concept of self-organization by thermodynamic segregation in functional ceramics. Model systems are advanced ceramic thin films, which will be studied under two defining cases: 1) deposition of supersaturated solid solutions or nanocomposites by magnetron sputtering (epitaxy) and arc evaporation. 2) post-deposition annealing (ageing) of as-synthesized material. Thin film ceramics are terra incognita for compositions in the miscibility gap. The field is exciting since both surface and in-depth decomposition can take place in the alloys. The methodology is based on combined growth experiments, characterization, and ab initio calculations to identify and describe systems with a large miscibility gap. A hot topic is to elucidate the bonding nature of the cubic-SiNx interfacial phase, discovered by us in TiN/Si3N4 with impact for superhard nanocomposites. I have also pioneered studies of self-organization by spinodal decomposition in TiAlN alloy films (age hardening). Here, the details of metastable c-AlN nm domain formation are unknown and the systems HfAlN and ZrAlN are predicted to be even more promising. Other model systems are III-nitrides (band gap engineering), semiconductor/insulator oxides (interface conductivity) and carbides (tribology). The proposed research is exploratory and has the potential of explaining outstanding phenomena (Gibbs-Thomson effect, strain, and spinodal decomposition) as well as discovering new phases, for which my group has a track-record, backed-up by state-of-the-art in situ techniques. One can envision a new class of super-hard all-crystalline ceramic nanocomposites with relevance for a large number of research areas where elevated temperature is of concern, significant in impact for areas as diverse as microelectronics and cutting tools as well as mechanical and optical components.
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