Research Of Ni,Ag And Nanosilica Doped Diamond-like Carbon Films By Electrodeposition Method

Using electrochemical method, diamond-like carbon films doped with heterogeneous elements have been deposited. The composition, structure and morphology of different kinds of films were investigated by X-ray photoelectron spectroscope (XPS), Raman scattering spectroscopy, Scanning electron microscopy (SEM), Atomic force microscopy (AFM) and Transmission electron microscopy (TEM). The tribological charactristics and bonding strength of these films were also investigated by UMT-2 universal micro-tribometer.The chief contents of this thesis include three parts as follow.(1) Synthesis and characterization of nickel-doped diamond-like carbon film electrodeposited at a low voltageNickel containing diamond-like carbon(Ni-doped DLC)films have been prepared on the Si substrate using electrochemical deposition method by choosing dimethylsulfoxide as carbon source and Nickel acetate as the dopant at relatively low voltage (150V). The morphology, composition, and microstructure of the film were investigated by means of X-ray photoelectron spectroscopy (XPS), Raman scattering spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, a UMT-2 universal micro-tribometer was used to evaluate the friction and wear behavior of the Ni-doped DLC film. Results show Ni-doped DLC films are uniform, compact and composed of spherical grains with a mean size of about 500 nm. the incorporation of nickel contributes to effectively decrease the residual stress and increase the bonding strength of the DLC film, which resulted in significantly increased wear resistance of the Ni-doped DLC film.(2) synthesis of silver nanoparticles containing diamond like carbon films via a facial electrochemical routeIn the present research, we choose silver nanoparticles as doping source and dimethylsulfoxide as carbon source, then diamond-like carbon film doped with silver nanoparticles was prepared via a simple and effective electrochemical route. The results show that zero-valence silver nanoparticles are stable and well-dispersed in the DLC films with unchanged size. And the incorporation of Ag nanoparticles in the carbon matrix caused a higher content of SP3 carbon than the undoped DLC film. Therefore, it is a simple method to achieve co-deposition of carbon and metal by using metal nanoparticles rather than metal salt solution as the dopant.(3) Synthesis of nanosilica-doped diamond-like carbon nano- composite films by electrochemical methodSilicon doped diamond-like carbon(SiO2-doped DLC)films have been prepared on the Si substrate using electrochemical deposition method by choosing dimethylsulfoxide (DMSO) as carbon source and nanosilica as dopant at relatively low voltage (150V). The morphology, composition, and microstructure of the film were investigated by means of X-ray photoelectron spectroscopy (XPS), Raman scattering spectroscopy and Atomic force microscopy (AFM). Moreover, the wettability and bonding strength of the Si02-doped DLC films were also investigated in our work. Results show that the doped silicon existed chiefly in the forms of Si-O bonds in films , and Silicon doping lowered the surface energy of the films ,which changed the films from the hydrophilic into the hydrophobic.The incorporation of silicon made the films have a better bonding strength, but that enhanced the carbon films graphitization.