Structural Evaluation of Graphene/SiC (0001) Grown in Atmospheric Pressure

Graphene growth on SiC in atmospheric pressure argon exhibits large terrace sizes and coverage over the entire substrate surface. Graphene growth and the resulting morphology are correlated with the characteristics of the growth chamber and the surface quality of the starting SiC substrate. Without in-situ surface preparation prior to growth, we observe “wrinkles” in the graphene surface. Graphitic-like disordered structures are formed at 1500°C while atomically flat graphene terraces are formed above 1600°C.

Edrioasteroidea and Edrioblastoidea

The edrioasteroids (seat stars) are a small but diverse group of Paleozoic (Lower Cambrian through Pennsylvanian) echinoderms known to include five morphologically distinct types of thecal construction. Domal and clavate thecae predominate, although some are globoid and others axially elongate. Adult thecal diameters range from 6 – 7 mm to approximately 9 cm, but 15 – 30 mm is the norm. Edrioasteroids are not common fossils, although when proper conditions for preservation existed, entire populations were often fossilized so that hundreds or even thousands of specimens can be recovered through excavation. Apparently, preservation depended upon catastrophic kills, most of which seem to have resulted from storm-deposited mud deeply burying the entire substrate surface area.