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The structures of the carbon sublayers in the annealed Co/C soft X-ray multilayers fabricated by using a dual-facing-target sputtering system have been characterized by transmission electron microscopy (TEM) and Raman spectroscopy (RS). The results suggest that the structural variations in the carbon layers can be roughly divided into three stages, i.e. ordering, crystalline and grain growth stages. At the ordering stage with annealing temperatures below 400°C, the amorphous carbon layers change from ones of bond-angle disorder and fourfold-bonding only to ones of threefold-bonding. At the crystalline stage, the amorphous carbon layers in the as-deposited multilayers crystallize to graphite crystallites in the annealing temperature range of 500–600°C. At the grain growth stage, the specimens are annealed at temperatures higher than 700°C. A growth in the graphite crystallite dimensions is observed, which is consistent with the TEM results.

The tribological properties of smooth diamond coatings sliding against ruby were studied using a pin-on-disk tribometer. Smooth diamond film surface was prepared by (i) deposition of thin nanocrystalline films in the thickness range from 0.2 to 2 μm and by (ii) post growth polishing. Excimer laser surface ablation, microwave plasma etching and mechanical lapping with diamond grit were applied for post growth polishing. A correlation of film surface properties examined with atomic force microscopy, Auger electron spectroscopy, Raman spectroscopy and stylus profilometry has been established with the tribological performance of the tested diamond films.

We have used a pin-on-disk tribometer with either a monocrystalline ruby or a 100Cr6 steel ball to evaluate the tribological properties of a series of polycrystalline chemical vapour deposition diamond films. Different polishing treatments of the as-grown films resulted in marked differences of their tribological behaviour. The friction and wear of smooth nanocrystalline diamond films was dependent on the surface morphology and roughness as well as the material transfer from the ball to the film. Microcrystalline films polished by laser irradiation, though being substantially rougher, showed a lower friction and minimal ball wear. Films polished by Ar-microwave plasma etching showed a similar behaviour as the laser-irradiated samples. However, the film with roughness comparable with the laser polished samples produced significantly higher ball wear. An unrivalled tribological performance was obtained with mechanically polished diamond films.

A polycrystalline diamond film was etched down to a depth corresponding to the grain size with 193 nm excimer laser radiation. Below a graphitic surface layer (GL) we have observed a highly stable layer (SL) which is conducting. Atomic force microscope measurements were made in order to characterize the topography and microfriction of these two surface layers. Features of the diamond facet structure are still visible in spite of smoothening by the laser etch process. An approximation for the friction coefficient of both surface layers yields values of between 0.01 and 0.1. The friction pictures of the GL show a local period length of about 70 nm, which could be a typical diameter for micrographitic grains. The SL is more disrupted than the GL and the appearance of a period length of about 70 nm has faded discernibly.

Polycrystalline diamond films of various microstructures were modified by large-area ArF laser irradiation. The modified film surfaces were characterized employing electron microscopy, mechanical profilometry and optical reflectometry. Laser irradiation was found to smooth the surface finish over a wide range of spatial frequencies covering microroughness imposed by the individual crystallites as well as waviness with periods exceeding the crystal sizes. No smoothening was achieved, however, for chemically non-uniform diamond films. The results can be rationalized in terms of laser-induced surface evaporation. Resistivity measurements revealed the simultaneous formation of a highly stable conductive surface layer upon laser irradiation.

The fabrication and behavior of an all‐carbon cathode for the growth of diamond films by dc discharge plasma chemical vapor deposition is presented. A graphite rod with a diameter of 2.5 mm was passivated in a methane dc plasma. During this process, the graphite was coated with pyrolytic carbon. Simultaneously, a thorn shaped protuberance (hereafter referred to simply as the thorn) of the same material grew from the end face of the rod towards the anode. The pyrolytic carbon prevented excessive sputtering of the cathode during diamond film synthesis in the hydrogen–methane plasma and the thorn presented a pointlike electron emitter providing a stable discharge. Using such cathodes, polycrystalline diamond films with well faceted crystallites have been grown at rates of approximately 5 μm/h. Nucleation and growth of individual, well faceted diamond crystallites even occurred on the cathode. When producing diamond films at methane concentrations above 1 vol %, a tubular form grows on the end of the cathode ...