Sn intercalation into the BL/SiC(0001) interface: A detailed SPA-LEED investigation

Growth of epitaxial graphene (EG) with desired properties and formation of new 2D interfaces can be achieved by intercalation of new elements into the carbon buffer layer (BL)/SiC(0001) interface. In this study, we investigated the formation of various ordered Sn-interface structures and, associated with it, the formation of quasi-free monolayer graphene by means of high-resolution spot profile analyzing low energy electron diffraction (SPA-LEED). The analyses of the diffraction patterns and the diffraction spot intensities allowed us to identify various long-range ordered interface structures as a function of the annealing temperature, e.g. (1 x 1), (root 3 x root 3)R30? and (root 39 x root 39)R16.1?. The ordering process at the interface and accompanying onset of deintercalation was controlled and monitored by high angular resolution and energy dependent measurements. V V Besides, for Sn sub-monolayer intercalation coverages, also a (root 3 x root 3)R30? reconstruction with respect to EG was found, which indicates a broken Kekul & eacute; structure of the pi-electrons in EG.

Automated summary

Growth of epitaxial graphene and formation of new interfaces can be achieved by intercalation of new elements into the carbon buffer layer/SiC interface. The formation of various ordered Sn-interface structures and quasi-free monolayer graphene was investigated by analyzing diffraction patterns and spot intensities. The ordering process at the interface and deintercalation were controlled and monitored by high-resolution and energy-dependent measurements.