Publications [#260678] of Volker Blum

Journal Articles

1. Schumann, T; Dubslaff, M; Oliveira, MH; Hanke, M; Fromm, F; Seyller, T; Nemec, L; Blum, V; Scheffler, M; Lopes, JMJ; Riechert, H, Structural investigation of nanocrystalline graphene grown on (6√3 × 6√3)R30°-reconstructed SiC surfaces by molecular beam epitaxy, New Journal of Physics, vol. 15 no. 12 (December, 2013), pp. 123034-123034, IOP Publishing [doi]
   (last updated on 2023/06/01)

   Abstract:
   Growth of nanocrystalline graphene films on (6√3 × 6√3)R30°-reconstructed SiC surfaces was achieved by molecular beam epitaxy, enabling the investigation of quasi-homoepitaxial growth. The structural quality of the graphene films, which is investigated by Raman spectroscopy, increases with growth time. X-ray photoelectron spectroscopy proves that the SiC surface reconstruction persists throughout the growth process and that the synthesized films consist of sp2-bonded carbon. Interestingly, grazing incidence x-ray diffraction measurements show that the graphene domains possess one single in-plane orientation, are aligned to the substrate, and offer a noticeably contracted lattice parameter of 2.450 Å. We correlate this contraction with theoretically calculated reference values (all-electron density functional calculations based on the van der Waals corrected Perdew-Burke-Ernzerhof functional) for the lattice parameter contraction induced in ideal, free-standing graphene sheets by: substrate-induced buckling, the edges of limited-size flakes and typical point defects (monovacancies, divacancies, Stone-Wales defects). © IOP Publishing and Deutsche Physikalische Gesellschaft.