Autor: |
Hidetsugu Shiozawa, Alicja Bachmatiuk, Andreas Stangl, David C. Cox, S. Ravi P. Silva, Mark H. Rümmeli, Thomas Pichler |
Jazyk: |
angličtina |
Rok vydání: |
2013 |
Předmět: |
|
Zdroj: |
Scientific Reports |
ISSN: |
2045-2322 |
Popis: |
Mirrored carbon-spirals have been produced from pressured ferrocene via the bilateral extrusion of the spiral pairs from an iron core. A parametric plot of the surface geometry displays the fractal growth of the conical helix made with the logarithmic spiral. Electron microscopy studies show the core is a crystalline cementite which grows and transforms its shape from spherical to biconical as it extrudes two spiralling carbon arms. In a cross section along the arms we observe graphitic flakes arranged in a herringbone structure, normal to which defects propagate. Local-wave-pattern analysis reveals nanoscale defect patterns of two-fold symmetry around the core. The data suggest that the bilateral growth originates from a globular cementite crystal with molten surfaces and the nano-defects shape emerging hexagonal carbon into a fractal structure. Understanding and knowledge obtained provide a basis for the controlled production of advanced carbon materials with designed geometries. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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