Monitoring the nanostructure of a hydrogenated fullerene-like film by pulse bias duty cycle

Abstract

The fullerene-like (FL) nanostructure is extremely important for fullerene-like hydrogenated carbon (FL-C:H) films that exhibit excellent mechanical properties and ultralow friction in ambient air, but the details of the contributing nanostructures are not well understood. We have prepared FL-C:H films with different morphologies and contents of FL nanostructures through tailoring the pulse bias duty cycle, and have investigated the contribution of the FL nanostructures. It is found that the straighter graphitic nanostructures in FL-C:H films could form under a high pulse bias duty cycle, and the low pulse bias duty cycle could increase the five-membered ring fractions, which results in more curved FL nanostructures with a larger curvature radius. Further investigation proved that the FL nanostructures with the more curved morphology could increase the mechanical properties and improve the tribological performance of the FL-C:H films. This work established a convenient controlling method to prepare FL-C:H films with tailored structures and performance.