电子背散射衍射法研究马氏珠母贝珍珠层中文石择优取向

贝壳珍珠层中的文石相对于在自然环境中生长的文石来说具有更优异的力学性能，这种力学性能取决于其独特的晶体排布方式。通过电子背散射衍射（EBSD）技术获得了马氏珠母贝中不同文石的结晶学取向信息，结果表明珍珠层中文石晶体的c轴均垂直于珍珠层层面，而a、b轴在平行珍珠层方向上具有两级取向畴结构：在初级畴结构内，相邻畴绕c轴偏转，导致不同畴之间a轴或b轴的取向差约64°。在次级畴结构内，文石板片围绕c轴偏转，导致不同畴之间a轴或b轴取向差在10°或20°左右。这种畴结构为我们认识珍珠层中文石的生长机理提供了有益线索。

Preferred Orientation of Aragonite in Nacre of Pinctada Martensii Shell Determined by Electron Backscatter Diffraction

Aragonite formed in biomaterials such as shells of bivalves has better mechanical properties due to the hierarchical structure when compared with aragonite grown in natural environment. Electron backscatter diffraction was applied to obtain the crystal orientation of nacre thin section. The results show that c-axes of most aragonite are perpendicular to the shell, a and b-axes are organized in two-level domain structure. In the primary domain structure, there are about a 64° misorientation of a-axes between different domains. In the secondary domain structure, the misorientation angles of different domains are around 10° or 20°. This kind of domain structure is important to study the growth mechanism of aragonite in nacre.