Vapor deposition and characterization of nanocrystalline nanolaminates

Compliant and Hard Cu(Ni)-C Nanocomposite Coatings

“…The measured H-values of 2-4 GPa for Cu-C are typical as reported (Jankowski, 2008) for nc Cu. It is seen in Figure 7 that as the indentation depth increases, the H-values begin to converge towards the known hardness for Silicon at ~10 GPa.…”

“…The variation in the Ni-C results appears to be dependent upon the specific regions of the surface that are probed wherein each of the nine indents is separated by 50-100 µm. The H-values for Ni-C are found to range from a lower bound that is typical for nanocrystalline (nc) Ni at 6-8 GPa (Jankowski, 2008) to upper bound values that are an average for a mixture of nc Ni and dlc C (Robertson, 2002).…”

“…nanostructured composites, in the form of a nanolaminate can be synthesized through an artificial fluctuation of composition through the vapor or aqueous deposition of layers with nanoscale thickness in one growth direction. An example (Jankowski, 2008) of the bottom-up, i.e. atomic scale, process is the physical vapor deposition method of magnetron sputtering.…”

On the Tapping Mode Measurement for Young’s Modulus of Nanocrystalline Metal Coatings

“…If there is a high amplitude to short-wavelength surface roughness, then multiple point contact can occur which could appear to artificially stiffen the mechanical response. Smooth surfaces and a nanocrystalline structure for tantalum (Ta), vanadium (V), and nickel (Ni) coatings are produced from the high-quench rates (>10 6 K⋅s −1 ) of the sputter deposition method [30][31][32][33][34]. The metals are coated onto polished flats such as semiconductor-grade silicon and sapphire wafers.…”

“…Details of the structural characterization for the Ta, V, and Ni sputter deposited coatings are reported elsewhere [30,35]. The characterization methods consisted of X-ray diffraction (XRD), transmission electron microscopy (TEM), and atomic force microscopy (AFM).…”