TY - JOUR
T1 - The effects of Si incorporation on the electrochemical and nanomechanical properties of DLC thin films
AU - Papakonstantinou, P
AU - Zhao, JF
AU - Lemoine, P
AU - McAdams, ET
AU - McLaughlin, JAD
N1 - 12th European Conference on Diamond Diamond-Like Materials Carbon Nanotubes Nitrides and Silicon Carbide (Diamond 2001), BUDAPEST, HUNGARY, SEP 02-07, 2001
PY - 2002/3
Y1 - 2002/3
N2 - Silicon-doped diamond-like carbon (DLC) films with a Si content of up to 20.2 at.% were grown on Al2O3-TiC substrate by plasma-enhanced chemical vapour deposition. The influence of Si addition on the bonding structure, nanomechanical and corrosion behaviour of the DLC films was investigated by Raman and X-ray photoelectron (XPS) spectroscopy,nano-indentation, potentiodynamic and electrochemical impedance spectroscopy (EIS). Silicon addition promoted the formation of sp(3) bonding and reduced the hardness. The deterioration of the nanomechanical properties is related to the increased hydrogen contentin the films, leading to the formation of a polymeric sp(3) CHn structure. The high hydrogen concentration in the Si-containing DLC samples was established by the increased Raman background slope. The EIS were analysed within the context of an equivalent circuit, whichincorporated two time constants representing the DLC coating and the solution/Al2O3-TiC interface, Introduction of Si in the DLC led to significant improvements in the corrosion resistance of DLC, as revealed by increase in the charge transfer resistance and reduction in the anodic current of the polarisation curves. Films with a thickness of 20 nm remained intact after the polarisation scan when the Si concentration was increased above 11.8 at.%. The improvements in corrosion resistance are related to the formation of a passivationlayer, which fills the pores present in the films. (C) 2002 Elsevier Science B.V. All rights reserved.
AB - Silicon-doped diamond-like carbon (DLC) films with a Si content of up to 20.2 at.% were grown on Al2O3-TiC substrate by plasma-enhanced chemical vapour deposition. The influence of Si addition on the bonding structure, nanomechanical and corrosion behaviour of the DLC films was investigated by Raman and X-ray photoelectron (XPS) spectroscopy,nano-indentation, potentiodynamic and electrochemical impedance spectroscopy (EIS). Silicon addition promoted the formation of sp(3) bonding and reduced the hardness. The deterioration of the nanomechanical properties is related to the increased hydrogen contentin the films, leading to the formation of a polymeric sp(3) CHn structure. The high hydrogen concentration in the Si-containing DLC samples was established by the increased Raman background slope. The EIS were analysed within the context of an equivalent circuit, whichincorporated two time constants representing the DLC coating and the solution/Al2O3-TiC interface, Introduction of Si in the DLC led to significant improvements in the corrosion resistance of DLC, as revealed by increase in the charge transfer resistance and reduction in the anodic current of the polarisation curves. Films with a thickness of 20 nm remained intact after the polarisation scan when the Si concentration was increased above 11.8 at.%. The improvements in corrosion resistance are related to the formation of a passivationlayer, which fills the pores present in the films. (C) 2002 Elsevier Science B.V. All rights reserved.
KW - electrochemical impedance
KW - pinholes
KW - Raman spectroscopy
KW - hardness
KW - corrosion
KW - Si-doped diamond-like carbon (DLC)
U2 - 10.1016/S0925-9635(01)00656-2
DO - 10.1016/S0925-9635(01)00656-2
M3 - Article
VL - 11
SP - 1074
EP - 1080
JO - Diamond and Related Materials
JF - Diamond and Related Materials
SN - 0925-9635
IS - 3-6, S
ER -