Strain fields in diamondlike amorphous carbon

Abstract

This paper reviews the fundamental ideas related to the concept of local atomic stresses and their application to the study of strain fields in ta-C. The calculations are based on Monte Carlo simulations within the empirical potential approach. We find that the stress distributions in ta-C are highly inhomogeneous, both in the bulk as well as in the surface and interface regions. There is a close relationship between local stress and hybridization. The most probable stress state for fourfold sites is compression, while threefold sites prefer to be under tension. Local-atomic behavior dominates longer-ranged stress conditions. Interdiffusion following thermal annealing is an important factor for the reduction of compressive stress in ta-C films grown on silicon substrates.