| In this thesis research, synthesis and characterization of a number of technologically and scientifically interesting B-C-N thin films was investigated. These solids, owing to their short and strong covalent bonds, have the potential to be very hard. Magnetron sputtering was utilized for film deposition and the films were characterization by a wide variety of techniques to obtain information on hardness, microstructure, composition, surface morphology, corrosion performance, and wear rate.; Ultrathin carbon nitride coatings were grown for use as protective overcoats in computer hard drives. In order to obtain an areal storage density of 100 Gbits/in2, the overcoat thickness is required to be within 2 nm, and the coating needs to be wear-resistant, smooth and defect-free. These requirements were satisfied for films grown under an optimum substrate bias where the energy distribution of the incoming ions was minimized and the substrate and target power supplies were pulsed at high frequency.; Synthesis of cubic boron nitride coatings was possible in films grown under intense ion bombardment, where the ion flux was controlled by an externally applied magnetic field. These films were prone to rapid delamination, especially in humid environments. Films grown under mild bombardment had the hexagonal structure, did not exhibit any tendency for delamination, and were relatively hard, with smooth surface morphology and were highly resistive. In order to obtain thick and adherent c-BN films, deposition of multilayer BN coatings was proposed. This was accomplished by varying the substrate bias as well as the incoming ion flux, however, no significant improvement in film adhesion was observed.; As an alternative to c-BN growth, deposition of boron carbide films was investigated. Such films exhibited high hardness, low surface roughness, along with high elasticity, and high wear resistance and did not show any signs of delamination under optimum growth conditions. The required deposition setup was uncomplicated, without the need for an external magnetic field or a pulsed substrate bias. The coatings were dense and disordered, with evidence of short-range order. |
