Berlin 2024 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 30: Poster: Proximity Effects in Epitaxial Graphene

O 30.7: Poster

Dienstag, 19. März 2024, 12:30–14:30, Poster A

Sn intercalated epitaxial graphene studied by scanning tunneling microscopy — •Dorothee Hennig, Chitran Ghosal, Zamin Mamiyev, and Christoph Tegenkamp — Institute of Physics, Technische Universität Chemnitz, Reichenhainer Str. 70, Germany

Electronically correlated 2D systems can be realized, for example, by adsorption of Sn on SiC(0001) [1]. The generation of such or similar phases as interfacial phases in the vicinity of epitaxial graphene (EG) promises the realization of novel quantum phases. Here we have investigated the intercalation of Sn on buffer layers (BL) on SiC(0001) using low temperature STM. We know from previous LEED investigations that a (1×1) phase forms first after deposition and subsequent heating. Further heating thins this phase further and (√3× √3)-reflexes appear [2]. The Sn(1×1)-phase below epitaxial graphene was found only locally with typical sizes of 2-3nm. Between these crystalline areas with distances of 5-10nm. In between, rather disordered Sn phases are formed, probably formed due to lateral strain effects or triggered by selective reactions at the interface due to the former BL. These centers also act as defects for EG, e.g. es seen by the (√3× √3)-reconstruction w.r.t. to EG imaged at bias voltage conditions close to Fermi energy. For the deluted phase, showing √3-reflexes, large islands (100nm) with a 6x6 periodicity similar to the BL reconstruction were found. Again, this finding suggests that the interface adsorption sites are defined by the former bonds of the BL with the SiC(0001) substrate.

[1] S. Glass et al., PRL 114, 247602 (2015). [2] Z. Mamiyev et al. Suf. Int. 34, 102304 (2022)

Keywords: Intercalation; Proximity Effects; Graphene; 2D materials; Correlation