First Principles Study Of Initial Stages Of Carbon Chain Growth On Ni (111) Surface

Because of the motivation for the miniaturation of electronics,low-dimensional carbon nano materials will play an important role in preparing nanometer materials of electronic devices, due to their special structures and wonderful properties. As an ideal covalent system, carbon chain, a rigid linear chain of monatomic carbon atoms, is expected to function as the component of molecular devices due to their exceptional physical and chemical properties. However, the 1D carbon chain is very active and it is still lacking of reliable and effective way to produce in experiments. The researchers have done much effort for their preparation and obtain some progress in the recent years. But it is cost much and difficult to control the grow progress with these methods. It is still a big challenge to prepare in the industry. Therefore, the study of carbon chain's growth mechanism is very important for its practical application.Carbonnano materials are usually prepared on the transition metal in industry all the time. In this paper, using spin-polarized density-functional theory calculation, we focus on the studies of carbon chain's growth on Ni (111) surface. C atoms are added"by hand"one by one to the surface. Combined with the results for these C adsorptions, a surface C structure is observed to develop in the form of chain creeping on the surface as the number of C atoms increases. The linear chain eventually joins to form a first threefold coordination site. Carbon chain is probably of cumulene type with nearly equivalent bond lengths according the previous studies. The bond lengths of carbon chain we obtain are in 2% difference, we consider their structures are similar with the cumulene type. We also have calculated the stabilities of a six-member carbon ring on the Ni (111) surface. The results show that the model whose carbon atoms are on the top of fcc and hcp sites is most stable. We also obtain that it is more favorable than a six-member carbon ring to grow on metal surface with a comparison of their formation energies. Our results will contribute to the studies of initial stages of carbon structures on metal surface.