Diamond-like carbon (DLC) and carbon nitride (C-N) films have the superior properties of hardness and wear-resistance. They have been investigated extensively for several applications. In this present study, DLC and C-N films were prepared on silicon wafers, stainless steel sheets, high speed steel blocks and WC-Co tips by the hollow cathode discharge method at the high deposition rate of 0.3μm/min. Silicon or tungsten carbide-cobalt was deposited as an interlayer in order to improve the adhesion of DLC and C-N films. Raman spectra of the DLC and C-N films showed distinct D and G bands. The indenting hardness of the C-N films was found to be larger than that of the DLC films. The intensity ratio of the D band to G band in the DLC films related linearly to the indenting hardnesses. On the other hand, the intensity ratios in the C-N films were almost constant in spite of the different conditions of deposition. The indenting hardness in the C-N films depended on the amount of contained nitrogen. The DLC films exhibited a lower friction coefficient compared with the C-N films.
Copper electrodeposition in a gel electrolyte has been studied by an electrochemical impedance spectroscopy (EIS). The electrochemical impedance was measured in a gel electrolyte containing various chloride concentrations. An inductive loop and a second capacitive loop were described on the Nyquist plot of electrochemical impedance at low frequency. These are called Faradaic impedance, which originates from the elementary steps of an electrode reaction. Warburg impedance was observed at low frequency in the diffusion limiting current region, indicating the contribution of the Cu(II) diffusion from the solution bulk to the electrode surface. The electrodeposition model of copper in the gel electrolyte was proposed on the basis of above-mentioned results. The numerical simulations were performed to confirm the proposed electrodeposition model and to obtain the kinetic parameters. Moreover, the influence of chloride was discussed from the obtained kinetic parameters.
The shape of electrodeposited nickel microprobes changed from a flat to an oval shape with the addition of propargyl alcohol in a nickel sulfamate bath ; propargyl alcohol is considered to have the function of the shape control. To research the effect of this organic additive on the function of the shape control, several alcohols having different structures, that is, states of carbon to carbon bonding, numbers of hydroxyl groups bonded to the terminal carbon, and numbers of carbons in the molecule, were investigated. From the result of preparing nickel microprobes electrodeposited from the bath containing the additive, an alcohol with a carbon-to-carbon triple bond and hydroxyl groups was effective to control the shape, and an alcohol without a triple bond did not have the function of shape control.