ATOMISTIC MECHANISMS OF ADHESION AND COMPRESSION OF DIAMOND SURFACES

The interactions which occur when two diamond {111} surfaces come into contact for short times have been examined via molecular dynamics. When both surfaces are hydrogen terminated these surfaces can be brought into contact, compressed, and separated with no damage to either surface. After compression and subsequent separation the surfaces and the bulk lattice regain their original geometry. The same is true if the hydrogen surface layer is totally removed from one of the lattices. In contrast, when both surfaces are partially hydrogen terminated, contact followed by compression and retraction results in the transfer of hydrogen atoms and the formation of a connective link of carbon atoms between surfaces. The formation of this connective neck of atoms and its subsequent fracture lead to significant damage to the surface and subsurface layers of the lattices.