Preparation of Nanostructured Si_xN_1−x Thin Films by DC Reactive Magnetron Sputtering for Tribology Applications

Abstract

In this work, nanostructured silicon nitride (Si_xN_1−x) thin films were prepared by reactive magnetron sputtering using an Ar/N₂ gas mixture of 1:1. The structures and fractional compositions of the prepared samples were determined by x-ray diffraction (XRD) and electron-dispersion x-ray diffraction (EDS) patterns as functions of inter-electrode distance. They showed that the prepared films were polycrystalline and the partial amount of silicon (x) is in the range 0.825–0.865 as the inter-electrode distance was in the range 2.5–7.5 cm. The particle sizes of the prepared nanostructures were determined by field-effect scanning electron microscopy (FE-SEM) to be about 38 nm. The measured Vickers microhardness of the prepared films showed relatively high values (570-750 kg.f/mm²) and decreased with decreasing film thickness, which is inversely proportional to the inter-electrode distance. These results encourage using these nanostructures for coating of wearable tools in industrial tribology applications.