Fig. 5: Friction test of hydrogen passivated diamond and a-C:H with 30 at.%H with target-oriented MLP model.
a, b Frictional energy landscape of hydrogen passivated diamond (111) interface. a Sliding PES corrugations ΔE calculated by DFT. b The potential profile (ΔE, red) and lateral force (F, blue) along the sliding pathways calculated by DFT and MLP. The step lengths along x ([\(1\bar{1}0\)]) and y ([\(11\bar{2}\)]) axis for the sliding systems are 0.25 Å and 0.435 Å. The inserted snapshots were the bidimensional representations of hydrogen passivated diamond (111) interface and the sliding directions, respectively. The gray and blue spheres representing the carbon and hydrogen atoms. c–e Typical bonding reorganization in friction process of a-C:H with 30 at.%H with target-oriented MLP model. c Snapshots of typical bonding reorganization in MD simulations of friction process with MLP model in friction target space. The black arrows at bottom left represented the direction of x and z axis in MD simulation. The gray and blue spheres represent the carbon and hydrogen atoms. d Change of the hybridization of C3 in the four bonding states of (c). The yellow and green square represented the sp2 bond and sp3 bond area. The MBA and SDBA represented the mean of bond angles and the standard deviation of bond angles (red and blue dot, respectively). e Frequency of sp3 jumping during the friction process.
