Molecular-dynamics simulations of atomic-scale friction of diamond surfaces

The friction which occurs when two diamond (111) hydrogen-terminated surfaces are placed in sliding contact is investigated for sliding in different crystallographic directions, as a function of applied load, temperature, and sliding velocity. We find a directional dependence to the friction coefficient, {μ}; that for certain crystallographic sliding directions {μ} increases with increasing load and as the temperature decreases; and that for the sliding speeds investigated here, {μ} is approximately independent of sliding velocity. We also found that the sliding velocity may become a factor for very slow, experimentally achievable sliding velocities when sliding in the [112{}] direction but not for sliding in the [11{}0] direction.