Berlin 2018 – scientific programme

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O: Fachverband Oberflächenphysik

O 58: 2D materials beyond graphene: TMDCs, silicene and relatives II

O 58.6: Talk

Wednesday, March 14, 2018, 11:45–12:00, MA 043

The Role of Substrate Symmetry on the Structural Properties of 2D Materials — •Antonio J. Martínez-Galera and José M. Gómez-Rodríguez — Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.

Predicting the properties that graphene and h-BN monolayers will exhibit after their growth on a certain substrate is a major challenge. While the influence on these properties of the electron configuration of the atoms comprising the underlying surface is well-known, the effects of substrate geometry still remain unclear. Herein, the structural properties of h-BN and of graphene monolayers grown on the rectangularly-packed Rh(110) surface are characterized and compared to those that both materials exhibit on substrates with different crystallographic orientations. The STM apparent corrugation of the quasi-one-dimensional moiré patterns found in both systems is unexpectedly small, compared to the values previously reported for a number of lattice-mismatched interfaces with hexagonal supports of 4d metals, in which, as in the case of Rh, the d band is half-filled and, as a result, a strong interaction of the 2D material layer with the substrate is expected. This discrepancy is explained by the differences in the possible binding landscapes at the interface for differently oriented substrates. In consequence, a rule is derived to predict how the corrugation at the interface, as well as the existence and the extent of sub-regions, within the moiré supercell, containing favorable sites for orbital mixing between h-BN or graphene and their supports depend on the substrate symmetry.