GROWTH OF CVD DIAMOND FILMS OVER BIOMEDICAL MATERIALS

Diamond films were nucleated on surgically implantable stainless steel , titanium and molybdenum substrates in a microwave plasma CVD reactor designed and built within these laboratories. Three different nucleat ion processes were adopted. These included mechanical abrasion with mi cron scale diamond dust, a proprietary subsonic impregnation method an d the application of a de bias voltage to the substrate. A combination of these methods resulted in a dramatic enhancement in the nucleation density on stainless steel. Experiments were also performed on titani um and molybdenum substrates once the optimum nucleation conditions on stainless steel had been ascertained. The films were characterised us ing a variety of different techniques including SEM, LIMA and XRD. The deposited films were found to be highly faceted and of high elemental purity. XRD analysis demonstrated that carbide phases had formed on e ach substrate prior to film growth.