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Inhomogeneity of Nacre Lamellae on the Nanometer Length Scale
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posted on 2012-09-05, 00:00 authored by Saeed Younis, Yaron Kauffmann, Leonid Bloch, Emil ZolotoyabkoWe present experimental evidence of inhomogeneous distribution
of organic inclusions within individual aragonitic lamellae forming
the nacre layer of mollusk shells. This nanoscale-inhomogeneity is
visualized in the Perna canaliculus (green mussel)
shells by the aid of high-angle annular dark field scanning transmission
electron microscopy (HAADF-STEM) in the tomography mode. Electron
tomography reconstructions of the three-dimensional distribution of
intracrystalline organic inclusions, ranging in size between 2 to
25 nm, clearly reveal 50 nm wide depletion zones adjacent to the organic
sheets between lamellae. The interrelation between the observed fine-scale
inhomogeneity of nacre layer and its improved mechanical properties
is discussed.