Me-Si-C (Me= Nb, Ti or Zr): Nanocomposite and Amorphous Thin Films
2012 (English)Licentiate thesis, comprehensive summary (Other academic)
This thesis investigates thin films of the transition metal carbide systems Ti-Si-C, Nb-Si-C, and Zr-Si-C, deposited at a low substrate temperature (350 °C) with dc magnetron sputtering in an Ar discharge. Both the electrical and mechanical properties of these systems are highly affected by their structure. For Nb-Si-C, both the ternary Nb-Si-C and the binary Nb-C are studied. I show pure NbC films to consist of crystalline NbC grains embedded in a matrix of amorphous carbon. The best combination of hardness and electrical resistivity are for ~15 at.% a-C phase. The properties of nc-NbC/a-C are similar to films consisting of nc-TiC/a-C. I further show that in a model system of epitaxial TiCx (x ~0.7) up to 5 at.% Si can be incorporated. At higher Si content, Si starts segregate out from the TiCx to the grain boundaries causing a loss of epitaxy. Higher amounts of Si into the Nb-Si-C and Zr-Si-C systems make them become amorphous. These amorphous structures are unstable under electron irradiation were they crystallize. I show that the cause of crystallization is driven by atomic displacement events.
Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2012. , 31 p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1561
IdentifiersURN: urn:nbn:se:liu:diva-85830Local ID: LIU-TEK-LIC-2012:46ISBN: 978-91-7519-730-2OAI: oai:DiVA.org:liu-85830DiVA: diva2:572989
2012-12-19, Schrödinger, Campus Valla, Linköpings universitet, Linköping, 10:15 (Swedish)
André, Benny, Dr.
Hultman, Lars, ProfessorEklund, Per, Dr.
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