Figure 7.

(a–c,e) SEM images show that film-like layers of organic matrix exist throughout all layers of the nacre. Film layer boundaries of various platelets are marked with arrows. Three layers (I–III) ascending from bottom left to top right can be seen clearly in (b) and a layer of 40 nm thickness is measured in (c). Film-like layers and nano-asperity imprints are also clearly revealed in (d) AFM image, and the screw dislocation core in (e) reveals that the organic matrix layers follow the spiral from one layer of platelets to the next. Scale bar, 2 μm.