Strain in twisted bilayer graphene grown by chemical vapour deposition on Ni surfaces.

• Twisted bilayer graphene synthesized on nickel substrate by CVD. • Raman and STM characterization of tBLG. • Determining the main features caused by the strain on the bilayer structure. • Simple models help to probe the main interrelations among STM features in CVD-tBLG. In this work, we have synthesised twisted bilayer graphene on nickel substrate by chemical vapour deposition. The Moiré superlattice generated by a misorientation in the stacking of two layers of graphene was studied. Raman spectroscopy was used to identify regions of interest on the films, in which scanning tunnelling microscopy (STM) was implemented to characterise the system in real space with atomic resolution, while also determining the main features caused by the strain on the bilayer structure. With the aid of simple models, we have probed relevant interrelations between features observed by STM and the heterostrain undergone by the film, which could be seen to suggest extra degrees of freedom in the sense of altering the properties of materials. [ABSTRACT FROM AUTHOR]