Berlin 2015 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 28: Poster Session II
MM 28.26: Poster
Dienstag, 17. März 2015, 18:30–20:30, Poster E
Characteristics of the artificial nanocrystalline calcium carbonate microlens arrays subjected to the amorphous/crystalline phase transformation — •Ingo Schmidt1, Kyubock Lee2, Emil Zolotoyabko3, Peter Werner4, Peter Fratzl1, and Wolfgang Wagermaier1 — 1Max Planck Institute of Colloids and Interfaces, Potsdam, Germany — 2Korea Institute of Energy Research, Daejeon, Korea — 3Technion - Israel Institute of Technology, Haifa, Israel — 4Max Planck Institute of Microstructure Physics, Halle, Germany
Natural biogenic materials with extraordinary properties, which often reveal a hierarchical arrangement of simple building blocks, serve as a comprehensive source for bio-inspired synthetic materials. Here we present structural aspects of nanocrystalline bioinspired calcite microlens arrays fabricated via an amorphous pre-phase. By the aid of polarized light microscopy we show that the calcite MLA crystallizes in spherulite-like patterns without changing the shape of individual microlenses. By mapping the local mean crystal orientations by microfocus X-ray diffraction, we find that the crystallization front propagates radially from the nucleation event, with the c-axis of calcite being the crystal growth direction. TEM observations indicate an average calcite crystal size of about 15-20 nm. Such nanocrystallites minimize birefringent effects and inhibit undesirable light scattering at grain boundaries. The knowledge of the MLA crystallization pathways may give us new information on biomineralization processes in calcite-based bio-composites.