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A Study of the Chemical Bonding and Microstructure of Ion Beam‐deposited CN x Films Including an XPS C 1s Peak Simulation
Author(s) -
Baker M. A.,
Hammer P.
Publication year - 1997
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199708)25:9<629::aid-sia313>3.0.co;2-5
Subject(s) - x ray photoelectron spectroscopy , microstructure , fourier transform infrared spectroscopy , chemical bond , amorphous solid , analytical chemistry (journal) , chemical shift , infrared spectroscopy , chemistry , materials science , crystallography , nuclear magnetic resonance , organic chemistry , physics , optics
The chemical bonding and microstructure of dual ion beam‐deposited CN xfilms with nitrogen contents in the range 20–33 at.% have been examined by Fourier transform infrared spectroscopy (FTIR) and x‐ray photoelectron spectroscopy (XPS). The FTIR spectra together with other published data have been used to construct a model microstructure of the CN xfilms. The XPS N 1s peak is composed of two components corresponding to N–sp 2 C and N–sp 3 C bonds. Using the quantified N 1s data and making certain assumptions, the model microstructure has been used as the basis of a C 1s peak simulation in which nine C components have been combined. At an N content of 20 at.% the simulation agrees well with the experimentally recorded XPS C 1s peak. The FTIR spectra, XPS N 1s peak shape and C 1s peak simulations support a microstructure of N substitution into an amorphous sp 2 /sp 3 hybridized carbon structure. Above an N content of ∽20%, a new (nitrile‐like) chemical form also emerges in the material, its abundance increasing with N content. It is proposed that this new structure occurs due to the presence, in the surface region of the condensing film, of C≡N dimers, which are formed when a C atom is surrounded by many N atoms. This molecule becomes trapped in the material and bonds to atoms at neighbouring sites. © 1997 by John Wiley & Sons, Ltd.