Eur. Phys. J. D (2013) 67: 50
https://doi.org/10.1140/epjd/e2013-30538-3

Regular Article

Carbon clusters near the step of Rh surface: implication for the initial stage of graphene nucleation^*

Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, P.R. China

^a e-mail: zhaojj@dlut.edu.cn

Received: 29 August 2012
Received in final form: 31 August 2012
Published online: 19 March 2013

Abstract

To understand the initial nucleation of graphene by chemical vapor deposition along metal step, carbon clusters (N = 1 ~ 24) near Rh (4 3 3) stepwise surface were systemically explored by first-principles calculations. Carbon chains are always more stable than carbon rings on stepped metal surface. Starting from C₆, carbon chains prefer two-end passivation on the metal step. A structural transition of carbon clusters from one-dimensional sp chains to two-dimensional sp² networks are found at C₁₀, which corresponds to the nucleation size at a wide range of chemical potentials. According to these theoretical results, we proposed that appropriately controlling the chemical potential may be helpful for observing the four stable carbon clusters along metal step and improving the quality of graphene.