FisMat2017 - Submission - View

Abstract's title: Growth and electronic structure of Graphene on Ni(100)
Submitting author: Alessandro Sala
Affiliation: University of Trieste and IOM-CNR
Affiliation Address: via Valerio 2, 34127 Trieste Italy
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Zhiyu Zou (ICTP, Trieste, Italy) Cinzia Cepek (IOM-CNR, Trieste, Italy) Francesca Genuzio (Elettra Sincrotrone Trieste, Italy) Tevfik Onur Mentes (Elettra Sincrotrone Trieste, Italy) Andrea Locatelli (Elettra Sincrotrone Trieste, Italy) Cristina Africh (IOM-CNR, Trieste, Italy) Giovanni Comelli (University of Trieste, Italy)

Nickel is one of the most technologically relevant substrates for graphene production due to its low cost, large availability and easy removal via chemical etching. The elevate carbon solubility in nickel determines lower growing temperature, appetible for large scale production, but also the tendency to form graphitic multilayers due to surface precipitation. This can be partially overcome in principle by rapid cooling, leaving monolayer graphene sheets heavily interacting with the Ni surface. Our group has already demonstrated how a controlled cooling can lead to the formation of a uniform interfacial layer of nickel carbide between Ni(111) surface and non-epitaxial graphene [1], thus enabling the creation of large non-interacting graphene sheets on this surface. Here we demonstrate how this strategy can be extended to the Ni(100) case, a prototypical example of symmetry-mismatched lattice and the most common surface phase in polycristalline nickel foils.

Graphene on Ni(100) grows via ethylene dosing (partial pressure 5x10-7 mbar) at ~ 580 °C and presents a variety of moirĂ© structures with either stripe-like or network morphology [2]. Previous VT-STM and XPS results and DFT calculation proved the creation of a carbidic phase at the interface via carbon segregation and its relation with the moirĂ© orientation [3]. The system was then characterized with LEEM/PEEM and microprobe-ARPES, with emphasis on the formation process of the carbidic phase and the effect of the related decoupling on the electronic structure of graphene. In particular, the combination of microprobe-ARPES and -XPS performed on single rotational domains shed some light on the possible confinement effects on the graphene Dirac states induced by the moire’ modulation. 

[1] L.L. Patera et al., ACS Nano 7, 7901 (2013); C. Africh et al., Sci. Rep. 6, 19734 (2016)
[2] Z. Zou, V. Carnevali et al., submitted
[3] Z. Zou, V. Carnevali et al., in preparation