Stress variations near surfaces in diamond-like amorphous carbon

TL;DR

This study uses Monte Carlo simulations to explore how surfaces influence atomic-level stresses and bonding hybridization in tetrahedral amorphous carbon, revealing inhomogeneous stress distributions and their correlation with local bonding types.

Contribution

It provides new insights into the relationship between surface-induced stress variations and atomic bonding hybridization in amorphous carbon.

Findings

Stress and bonding hybridization distributions are highly inhomogeneous near surfaces.

Compressive stress favors sp^3 bonding, tensile stress favors sp^2 bonding.

Stress-bonding relationships observed in the bulk also hold near surfaces.

Abstract

Using Monte Carlo simulations within the empirical potential approach, we examine the effect produced by the surface environment on the atomic level stresses in tetrahedral amorphous carbon. Both the distribution of stresses and the distributions of sp^2 and sp^3 atoms as a function of depth from the surface are highly inhomogeneous. They show the same close relationship between local stress and bonding hybridization found previously in the bulk of the material. Compressive local stress favors the formation of sp^3 sites, while tensile stress favors the formation of sp^2 sites.