Kim A. Marshall

The analytical impact of power control in a radio frequency glow discharge optical emission plasma

Direct current (dc) and radio frequency (rf) glow discharge power control requirements, and limitations are described. The differences between dc and rf power control are explored. The various difficulties faced with rf power regulation are listed and explained. In light of these challenges, the appropriate design goals for an rf glow discharge power supply and control system are outlined. The design and implementation of such a new rf design is then detailed. The ability of this new design to deal with the various rf difficulties is discussed. This design is evaluated and experimental evidence that it functions as anticipated is collected, presented, and discussed. This new rf power supply design is shown to have significant new capabilities.

Elemental depth profiling of coated and surface-modified materials by GD-OES: hard coatings on cutting tools

Abstract Recent developments in glow discharge optical emission spectrometry (GD-OES) resulted in establishing this technique as a powerful tool for quantitative elemental depth profile analysis of coating–substrate systems and surface-modified materials. The present status of GD-OES as an analytical discipline is reviewed, methodology of quantitative depth profile analysis is described and the resulting analytical performance is presented on examples of PVD/CVD hard coatings on cemented carbides and high-speed steels. It is shown that with GD-OES, it is possible to analyze the depth-resolved elemental composition of the coating and the substrate in a relatively simple experimental setup and with an accuracy approaching the bulk analysis of homogeneous materials.