@article{8863,
  author = {D. Garcia Rodriguez and M.A. Gleeson and J.V. Lauritsen and Z.S. Li and X. Yu and J.W. Niemantsverdriet and C.J. Weststrate},
  title = {Iron carbide formation on thin iron films grown on Cu(100): FCC iron stabilized by a stable surface carbide},
  abstract = {Thin iron films evaporated onto Cu(1 0 0) were carburized using ethylene to produce iron carbide surfaces for use as model systems in experimental research. XPS and AES confirm that ethylene dissociation produces a pure iron carbide. A maximum of 0.5 ML carbon can be deposited for film thicknesses below 12 ML where Fe grows as γ-iron (FCC). For thick, BCC-Fe(1 1 0) films, post-treatment with ethylene leads to carbon coverages beyond 0.5 ML where some carbon diffuses into the bulk. The film remains α-iron (BCC) and a different surface carbide with a (4 × 3) unit cell is found. On the thin FCC-Fe(1 0 0) films, carbon reconstructs the surface into a p4g(2 × 2)-Fe2C layer which has a special stability and acts as a carbon trap that prevents carbon diffusion into the bulk. Fe2C is thermally stable up to 700 K above which Fe diffuses into the copper substrate while leaving graphitic carbon behind. Carbon segregates to the surface during evaporation of iron on top of an Fe2C-covered FCC-Fe film and causes the film to retain the FCC structure up to a thickness of at least 30 ML, far beyond 12 ML where BCC-Fe forms on Cu(1 0 0) in absence of surface carbon.
},
  year = {2022},
  journal = {Applied Surface Science},
  volume = {585},
  pages = {152684},
  month = {05/2022},
  doi = {10.1016/j.apsusc.2022.152684},
  language = {eng},
}