Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 25: Focus Session: Atomic-Scale Characterization of Correlated Ground States in Epitaxial 2D Materials

O 25.7: Vortrag

Dienstag, 6. September 2022, 12:45–13:00, H2

Sn intercalation of the buffer layer/SiC(0001) interface studied by SPA-LEED and STM — •Zamin Mamiyev, Chitran Ghosal, and Christoph Tegenkamp — Institut für Physik, Technische Universität Chemnitz, Chemnitz, Germany

Growth of graphene (Gr) with tailored properties and the simultaneous formation of an exotic 2D interface can be achieved by intercalation of different species below the buffer layer (BL) on SiC(0001). In this regard, Sn is interesting because of a potential Mott ground state imposed by the triangular lattice of Sn atoms at the interface and protected by the Gr layer. Therefore, we studied Sn-intercalation on BL/SiC(0001) by means of spot profile analysis low energy electron diffraction (SPA-LEED) and STM. Starting with a 6√3×6√3 BL surface, we deposited monolayers of Sn at RT and annealed subsequently to higher temperatures. The formation of quasi-free standing monolayer graphene (QFMLG) is confirmed by an apparent 1×1 periodicity. Further insights for a successful decoupling of QFMLG were gained from inspecting the bell shape broadening of the diffraction spots, which is characteristic of weakly coupled 2D systems on surfaces. By further optimization of the post-intercalation treatment, a Sn-induced √3×√3 reconstruction at the interface was achieved. Moreover, detailed studies showed a simultaneous transformation of 6√3×6√3 periodicity into a (√39×√39)R16.1^∘ reconstruction with corresponding domains. Interestingly, the new periodicities formed by the intercalant atoms are triggered by the former symmetry of the BL structure.