First-principles analysis of C2H2 molecule diffusion and its dissociation process on the ferromagnetic bcc-Fe(110) surface

Minoru Ikeda, Takahiro Yamasaki, Chioko Kaneta

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7 Citations (Scopus)

Abstract

Using the projector-augmented plane wave method, we study diffusion and dissociation processes of C2H2 molecules on the ferromagnetic bcc-Fe(110) surface and investigate the formation process of graphene created by C2H2 molecules. The most stable site for C2H2 on the Fe surface is a hollow site and its adsorption energy is -3.5 eV. In order to study the diffusion process of the C2H2 molecule, the barrier height energies for the C atom, C2-dimer and CH as well as the C2H2 molecule are estimated using the nudged elastic band method. The barrier height energy for C2H2 is 0.71 eV and this indicates that the C 2H2 diffuses easily on this FM bcc-Fe(110) surface. We further investigate the two step dissociation process of C2H 2 on Fe. The first step is the dissociation of C2H 2 into C2H and H, and the second step is that of C 2H into C2 and H. Their dissociation energies are 0.9 and 1.2 eV, respectively. These energies are relatively small compared to the dissociation energy 7.5 eV of C2H2 into C2Hand Hin the vacuum. Thus, the Fe surface shows catalytic effects. We further investigate the initial formation process of graphene by increasing the coverage of C2H2. The formation process of the benzene molecule on the FM bcc(110) surface is also discussed. We find that there exists a critical coverage of C2H2 which characterizes the beginning of the formation of the graphene.

Original languageEnglish
Article number384214
JournalJournal of Physics Condensed Matter
Volume22
Issue number38
DOIs
Publication statusPublished - 2010 Sep 29
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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