Crystal orientation regulation in ostrich ggshells
Journal of Crystal Growth 233 (2001) 548-554，-0001，（）：
The structure and crystallographic orientation of diﬀerent layers (the cone layer, palisade layer and the crystal layer) in ostrich eggshells were studied by scanning electron microscope (SEM), X-ray diﬀraction (XRD) and transmission electron microscope (TEM) with selected area electron diﬀraction (SAED). It is found that the degree of 001 preferred orientation enhanced from inner to outer ostrich eggshells. A crystallographic orientation regulation was observed for the ﬁrst time. The adjacent 1-5 calcite crystals with the same three-dimensional orientation are proposed to form a crystalline cluster with the size of several microns. The a-axes in the neighboring clusters orient from several degrees to tens of degrees.