Details

Autor(en) / Beteiligte

• Zemek, J.
• Houdkova, J.
• Jiricek, P.
• Jelinek, M.
• Jurek, K.
• Kocourek, T.
• Ledinsky, M.

Titel

In-depth distribution of elements and chemical bonds in the surface region of calcium-doped diamond-like carbon films

Ist Teil von

• Applied surface science, 2021-02, Vol.539, p.148250, Article 148250

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2021

Quelle

ScienceDirect

Beschreibungen/Notizen

• [Display omitted] •Calcium carbonate partially decomposes during PLD deposition.•In-depth distributions of elements and resolved bonding states are inhomogeneous.•Surface of Ca-doped DLC layers is enriched by CaCO3 and C sp3.•Ca doping induces structural conversion from C sp3 to C sp2 in a sub-surface region. In the present work we determined surface composition and chemical bonds at the top surface and in a shallow sub-surface region of the calcium-doped diamond-like carbon (DLC) layers using angular-resolved photoelectron spectroscopy (ARXPS) aided by the Maximum Entropy Method (MEM). The resulting non-destructive depth profiles showed that the composition and the chemical bonding vary significantly on the way from the top surface to the shallow sub-surface region. We demonstrate, for the first time, that Ca doping induced (i) the accumulation of the calcium carbonate, CaCO3, at the surface, while the calcium oxide, CaO, is locatedin a deeper sub-surface region, (ii) structural conversion from the C sp2-rich top surface observed in the undoped DLC layer to the C sp3-rich top surface of the Ca-doped DLC samples, and (iii) conversion in the opposite direction which occurred in a sub-surface region. Our conclusions are consistent with Raman and Ion Surface Scattering spectra. Obtained results can be useful for deeper understanding the interaction between doped DLC layer surfaces with surroundings and particularly with living tissue.