Graz Advanced School of Science, PHYSICS COLLOQUIUM OF THE UNIVERSITY OF GRAZ AND THE GRAZ UNIVERSITY OF TECHNOLOGY

Abstract:

The experimental isolation of a single layer of graphite, graphene, and the discovery of its

unique electronic properties have led to a surge of experimental and theoretical studies.

While numerous promising graphene-based applications have been suggested, ranging

from novel sensors to materials for spintronics or energy applications, the fundamental

understanding of the interaction of a graphene sheet with a substrate are still lacking.

In this talk, I will briefly discuss the shortcomings of the present workhorse of materials

modeling, density functional theory (DFT), for the description of the graphene-metal

interface, and show that a many-body (RPA) approach [1] allows to recapture the relevant

non-local (van der Waals) contributions. On the basis of these calculations, we find that

even in the case of graphene/Ni(111), where a “strong” interaction has been proposed, the

adsorption is driven by subtle electronic effects [2].

By mapping the many-body calculations on a computationally cheaper approach we could

also investigate several applied aspects of the graphene-metal interfaces. While the

growth of a high-quality graphene film on Ni substrate is indeed facilitated by low barriers

for the healing of defects [3], it is often preceded by the formation of a Ni2C surface

carbide [4]. In the final part, I will show how the interaction strength can be tuned by the

intercalation of metallic adlayers, leading to the formation of nanostructured templates.

[1]L. Schimka, et al., Nature Materials 9, (2010) 741.

[2] F. Mittendorfer, et al., Phys. Rev. B 84, (2011) 201401.

[3] P. Jacobson, et al., J. Phys. Chem. Lett. 3 (2012) 136.

[4] P. Jacobson, et al., ACS Nano 6 (2012) 3564.