Ion beam analysis and Raman characterisation of coatings deposited by cosputtering carbon and chromium in a closed field unbalanced magnetron sputterion plating system

A novel non-hydrogenated a-C coating has been deposited by sputtering carbo n and chromium targets in a closed field unbalanced magnetron sputter ion p lating system, with a metallic adhesion layer between the substrate and the cosputtered layer. The properties of these new carbon coatings have been p reviously compared with those of more conventional hydrogenated metal-conta ining DLC. Reciprocating and pin-on-disk friction and wear tests have shown that the new carbon coatings have a lower friction coefficient and that th eir wear resistance is more than one order of magnitude higher than metal-c ontaining hydrogenated DLC coatings. This paper presents an initial study of the composition and structure of th ese new coatings. Rutherford and Non-Rutherford backscattering of alpha par ticles and protons are used for studying the stoichiometry and for the dete rmination of impurities. Elastic recoil detection analysis (ERDA) is used f or depth profiling of hydrogen. Raman spectroscopy is used to investigate t he structure of the different carbonaceous layers. (C) 1999 Elsevier Scienc e S.A. All rights reserved.