Effect of the graphite domain direction on the friction coefficient of tetrahedral amorphous carbon nitride

Polarized surface -enhanced Raman scattering was applied to lowand high- friction surfaces of tetrahedral amorphous carbon nitride (ta-CNx) to reveal the presence of the graphite structure and investigate the angular dependence of the graphite domains that formed on the topmost surface. The measured D peak intensity differed along the incident electric field toward the sliding direction, from parallel to perpendicular and armchair edges may be present. The results for the lowfriction surface indicated that graphite domains exist on the ta-CNx disk and transfer layer on the counter material (Si3N4) ball in directions different from the sliding friction, which suggests an incommensurate configuration.