Nanoscale investigation of indentation, adhesion and fracture of diamond (111) surfaces

Molecular dynamics simulations have been used to model the dynamics of indentation and the resulting damage for a ( i i l ) surface of a (1 × 1) hydrogen terminated dmmond ttp interacting with the ( l i d surface of both a (I × 1) hydrogen terminated dmmond crystal and a non-hydrogen terminated dmmond crystal. In both cases, mdentation can result m a non-adhesive (~ e . elastic) or an adhesive 0 e., plastic) interaction depending on the maximum value of the apphed load Further, adhesion ts usually accompamed by fracture and is independent of where the t~p contacts the surface In the case of the hydrogen terminated crystal, the dmmond crystal structure is slgmficantly disrupted as a result of the indentation When the hydrogen is removed from the crystal's surface, adhesion occurs at lcwer loads than previously, observed. However, the crystal structure ts not significantly altered as a result of the indentation The state of the surface &ctates ihe type of indentation mechvnisrn