DIAMOND NUCLEATION ON STEEL SUBSTRATES

The aim of this work is an investigation of the nucleation density of diamond deposited by various chemical vapour deposition methods on steel substrates coated with sputtered refractory metal (RM) layers. We followed the diffusion of iron in the RM layer and the formation of iron and RM carbides by X-ray diffraction and energy-dispersive X-ray analysis. The diamond nucleation density is correlated to the thickness of the RM layer and the type of steel. We show that iron diffusion requires a minimum thickness of the intermediate layer. The originally low nucleation density can be significantly enhanced by microscopic surface roughness or by seeding with microscopic salt or diamond crystals.