Frictional properties of diamondlike carbon layers

Hard diamondlike carbon layers have been deposited on silicon by rf plasma deposition using acetylene as working gas. For the first time the dependence of the sliding friction coefficient m on the water vapor content of a nitrogen atmosphere was measured. An increase of m with increasing humidity has been found, with m ranging from 0.01 to 0.19. A steel ball was employed as the friction partner. The wear of the layers has been assessed by measuring their durability during friction experiments. It has been shown, contrary to other publications, that the durability has a maximum in the range 0.5-5.0% of relative humidity.