Development of a Novel Cathodic Plasma/Electrolytic Deposition Technique Part 2: Physico-chemical Analysis of the Plasma Discharge

A novel plasma system has been developed recently for the deposition of carbon and titanium thin films on metal and metal alloy substrates. Unlike other deposition techniques, the process occurs in liquid precursors and a plasma discharge is created and confined around the cathode in a superheated vapour sheath surrounded by the liquid phase. This paper presents a detailed analysis on the physico-chemical mechanisms underlying this process. A correlation has then been carried out between the voltage / current characteristics of the process and the consecutive physical phenomena occurring during the process (vapour phase formation, plasma discharge initiation and evolution). A description of the different coatings (graphite and titanium dioxide) deposited with this technique has been carried out with an attempt to correlate the structure and composition of these films with the composition and physical characteristics of the plasma discharge. This analysis allowed the construction of a first dissociation and deposition mechanism for this new plasma system.