SURFACE MELTING IN THE HETEROEPITAXIAL NUCLEATION OF DIAMOND ON NI

Surface melting associated with the heteroepitaxial nucleation of diam ond on Ni was investigated. Scanning electron microscopy of quenched s amples revealed flow patterns and a recrystallized surface morphology. A combination of techniques including in situ optical monitoring, dif ferential thermal analysis, Auger depth profile analysis, and cross-se ction transmission electron microscopy (TEM) analysis were performed t o identify the nature of the molten layer. Data obtained from differen t experiments were in good mutual agreement. All experimental results strongly indicated that a molten Ni-C-H surface layer was involved in the nucleation process. The presence of both carbon and atomic hydroge n played an important role in the depression of the melting point whic h was measured to be > 300 degrees C less than the melting point of pu re Ni. (C) 1998 Published by Elsevier Science B.V. All rights reserved .