Atomistic Frictional Properties of the C(100)2x1-H Surface
Figure 3
(a) The total energy difference (with separated configuration at 25 Å) of two C(100)2x1-H surfaces with incrementally decreasing separation, a cohesive interaction at approximately 4.5 Å separation is observed with increasingly repulsive interactions at smaller spacing (distance as measured between the carbon atoms of the dimer between upper and lower surfaces). (b) Total energy of interaction of C(100)2x1-H surfaces at fixed distance and load while surfaces are slid in the (100) plane: open circle load is 0.0326 nN, open square load is 0.4034 nN, solid circle load is 1.1694 nN, and solid square load is 2.3590 nN. (c) Geometry of interacting surfaces at 3.24 Å (Figure 1(c)) spacing when translated ~1.2 nm into relative minima, showing relative positions of opposing hydrogen atoms. (d) Electron density difference map of part (c) coloration as described in Figure 2(c). (e) Friction force derived from part (b) as a function of applied load, coefficient of friction is μ = 0.157.
