Influences of Film Deposition Condition on Friction of Diamond-Like Carbon Film: A Theoretical Investigation

Abstract

We theoretically investigated influences of film deposition condition on a friction of diamond-like carbon (DLC) film using our developed molecular dynamics method. The method can deal with chemical reactions on the basis of our original stochastic equation. DLC slab model was firstly constructed, and carbon atoms were deposited onto its surface with various kinetic energies (1, 10 and 30 eV) to mimic physical vapor deposition process. Lower sp 3 carbon concentration and density were obtained for the 1 eV case and "subplantation" phenomenon was found for each model. The dynamical friction of the deposited DLC film/iron oxide combination was also simulated. The friction coefficient for the deposited film with kinetic energy of 1 eV was much lower than that of 10 and 30 eV cases due to the friction-induced structural change. The simulations provided us an important insight on DLC film preparation to achieve low friction regime.

Friction Reduction Mechanism of Hydrogen- and Fluorine-Terminated Diamond-Like Carbon Films Investigated by Molecular Dynamics and Quantum Chemical Calculation

“…The bond strength between carbon atoms basically decreases with increasing interatomic distance. Onodera et al reported that the covalent interaction for the sp 3 , sp 2 , and sp carbon atoms diminished around 4.0 and 2.5 Å in the interatomic distance, respectively . The details of the parametrization method of R max , which were determined on the basis of bond population calculated by DFT, has been reported in ref .…”

“…Onodera et al reported that the covalent interaction for the sp 3 , sp 2 , and sp carbon atoms diminished around 4.0 and 2.5 Å in the interatomic distance, respectively . The details of the parametrization method of R max , which were determined on the basis of bond population calculated by DFT, has been reported in ref . When a reaction is judged to occur based on eq , potential parameters are automatically switched, realizing a fast calculation of chemical reaction.…”

“…A vacuum region in the cell was constructed by extending the cell size in one direction, forming the surface. The extended structure was well relaxed using MD at 300 K. The details of the modeling method have been reported in our previous paper . The pictures of constructed models are shown in Figure .…”

“…The extended structure was well relaxed using MD at 300 K. The details of the modeling method have been reported in our previous paper. 21 The pictures of constructed models are shown in Figure 1. The top layer of the DLC model (Figure 1a) is mainly composed of sp 2 -carbon atoms, which consists of the experimental obeservation.…”

Mixed lubrication of steel by C18 fatty acids revisited. Part I: Toward the formation of carboxylate

“…The program is based on a TB-QC calculation program named "COL-ORS" [20,21] and a classical molecular dynamics (MD) program named "RYUDO" [22]. In the UA-QCMD program, charges, potentials, and binding energies, etc.…”