ORIENTED DIAMOND GROWTH ON PLATINUM VIA A METAL-CARBON-HYDROGEN LOW-PRESSURE PROCESSING ROUTE

Oriented diamond crystals have been formed on polycrystalline platinum by a multi-step low-pressure solid-state carbon source processing rou te employing Pt as the metallic solvent. The processing routine includ ed the implementation of a high-temperature metal hydrogenation step a t 900 degrees C, followed by an increasing metal carbonization step at temperatures of 1100, 1200, 1300 and 1400 degrees C. For the carboniz ation step at temperatures of 1300 degrees C and greater, prior to exs olution and diamond formation, regions with oriented diamond particles were observed. However, when performing this procedure at less than 1 300 degrees C only randomly oriented particles were observed. (C) 1997 Elsevier Science S.A.