Observational Geology of Graphene, at the Nanoscale

As the available length ranges expand, graphene begins to show its anticipated polycrystallinity. Its texture; revealed with modern comprehensive microscopy in recent work by Kim et al., includes coherent domains/grains oriented randomly yet with an intriguing degree of regularity. The domains are stitched together by pentagons and heptagons aligned into the grain boundaries. The challenge is now to deduce the mechanisms of formation based on observations and then to find ways to control the morphology toward useful properties and applications.