▎ 摘　　要

Amorphous carbon (a-C) films can transform to graphene under the catalysis of some transition metals, while the transformation mechanisms are still not clear for the experimental techniques unable dynamically tracing the diffusion of atoms. In this work, an atomic-level simulation method-molecular dynamics simulation was adopted to conquer the disadvantage of experimental techniques. Using this method, the microstructure evo-lution processes of a-C films with different thicknesses on the Cu(0 0 1), Cu(1 1 0) and Cu(1 1 1) surfaces were studied. It was found that the a-C films directly transformed to single-layer or multilayer graphene without the dissolving and precipitating processes of carbon atoms, and the final product strongly depends on the surface density of a-C films. Specifically, the a-C films transformed to a piece of equal-surface-density single-layer or multilayer graphene. However, for the limited relaxation time, the formed graphene contain different amount of defects; and the quality analysis of graphene implies that the Cu(0 0 1) crystal plane owns higher catalyzing ability than the other two planes. Detailed microstructure analysis indicates the a-C films gradually transformed to graphene by breaking the vertical bonds and reconstructing the horizontal bonds. And the variation of the bonds make the six-carbon (C6) rings to be the main rings and to parallel the Cu substrate.