Characterization of amorphous and nanocomposite Nb-Si-C thin films deposited by DC magnetron sputtering
2013 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 545, 272-278 p.Article in journal (Refereed) Published
Two series of Nb-Si-C thin films of different composition have been deposited using DC magnetron sputtering. In the first series the carbon content was kept at about 55 at.% while the Si/Nb ratio was varied and in the second series the C/Nb ratio was varied instead while the Si content was kept at about 45 at.%. The microstructure is strongly dependent on Si content and Nb-Si-C films containing more than 25 at.% Si exhibit an amorphous structure as determined by X-ray diffraction. Transmission electron microscopy, however, induces crystallisation during analysis, thus obstructing a more detailed analysis of the amorphous structure. X-ray photo-electron spectroscopy suggests that the amorphous films consist of a mixture of chemical bonds such as Nb-Si, Nb-C, and Si-C. The addition of Si results in a hardness decrease from 22 GPa for the binary Nb-C film to 18 - 19 GPa for the Si-containing films, while film resistivity increases from 211 mu Omega cm to 3215 mu Omega cm. Comparison with recently published results on DC magnetron sputtered Zr-Si-C films, deposited in the same system using the same Arplasma pressure, bias, and a slightly lower substrate temperature (300 degrees C instead of 350 degrees C), shows that hardness is primarily dependent on the amount of Si-C bonds rather than type of transition metal. The reduced elastic modulus on the other hand shows a dependency on the type of transition metal for the films. These trends for the mechanical properties suggest that high wear resistant (high H/E and H-3/E-2 ratio) Me-Si-C films can be achieved by appropriate choice of film composition and transition metal.
Place, publisher, year, edition, pages
2013. Vol. 545, 272-278 p.
Magnetron sputtering, Carbide, Amorphous structure, Structure characterization, Mechanical properties, Electrical properties
IdentifiersURN: urn:nbn:se:uu:diva-209841DOI: 10.1016/j.tsf.2013.08.066ISI: 000324820800045OAI: oai:DiVA.org:uu-209841DiVA: diva2:659942