A diamond-like carbon (DLC) film is mainly composed of both sp
3-bonded atoms as in diamond and sp
2-bonded atmos as in graphite. Many reports concerning their mechanical and tribological properties have been published, while there have not been enough studies on deformation mechanism yet. In the present paper, the change of bonding form under uniaxial loading is investigated using the molecular dynamics. From uniaxial tension analyses of the DLC film obtained by the random walk method, the content rate of sp
3-bonded atom decreases as opposed to that of sp
2-bonded atom under the tension. The morphological changes of bonding which are accompanied by the annihilation and the generation of the bonding forms are observed. Moreover, rearrangement of bonding caused by the combination of these changes is confirmed. By these changes, local atomic environment which includes the back-bond interaction comes to stabilize energetically. The first peak of the radial distribution function has almost the same position between the initial state and the loading state of ε
11=0.1. Therefore, it is concluded that bending and torsion effects between atoms induced by the employed interatomic potential are more predominant rather than bond-stretching under the deformation. However, the well-established Tersoff type potential for diamond structure cannot represent its torsion effect which has been acknowledged by the molecular orbital calculations.
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