Nano-Composite Structure of Nacre Biocrystal.

Xavier Bourrat (1) , Marthe Rousseau (2) , Evelyne Lopez (2) , Philippe Stempflé (3)

1 ISTO - Institut des Sciences de la Terre d'Orléans
2 BOME - Biologie des organismes marins et écosystèmes
3 LGP - Laboratoire Génie de Production

Intermittent-Contact Atomic Force Microscopy with phase detection imaging reveals a nanostructure within the tablet (Pinctada maxima). A continuous organic framework divides each tablet into nanograins. Their mean extension is 45nm. Transmission electron microscopy performed in the darkfield mode evidences that intracrystalline matrix is highly crystallized and responds like a ‘single crystal'. The organic matrix is continuous inside the tablet, mineral phase is thus finely divided but behaves in the same time as a single crystal. It is proposed that each tablet results from the coherent aggregation of nanograins keeping strictly the same crystallographic orientation thanks to an hetero-epitaxy mechanism.

Domains: Mineralogy

Xavier Bourrat, Marthe Rousseau, Evelyne Lopez, Philippe Stempflé. Nano-Composite Structure of Nacre Biocrystal.. 2005, 6p. ⟨hal-00092027⟩