LEED patterns of a 6H-SiC(000-1) sample after graphitization. The circles indicate the (1 × 1) SiC spots, the white arrows the (3 × 3) SiC spots, and the rose arrows point to faint SiC(2 × 2)C spots. The dashed (quarter) circle shows the ringlike pattern of graphene. The modulated intensity of FLGs signal corresponds to the distribution of rotation angles for the first graphene layer compared to the SiC surface with some preferential orientations (the brightest spots).
Tiberj et al. Nanoscale Research Letters 2011 6:171 doi:10.1186/1556-276X-6-171