Domain structure and defects of highly ordered Bi4Si3O12 micro-crystals

Highly ordered Bi4Si3O12 micro-crystals were prepared at normal atmosphere. Phase identification of the prepared crystals was accomplished by X-ray diffractometer (XRD). Domain structure and defects were characterized by environmental scanning electron microscopy (ESEM). XRD shows that the obtained micro-crystals are of eulytite structure with chemical formulation of Bi4Si3O12. A highly ordered growth pattern is confirmed due to the faster growth of the {124} faces than that of the {204} faces by ESEM. The growing process of the domain structure is of pollen parent and filial generation pattern. The filial generations of Bi4Si3O12 crystals are generated from the pollen parent. Cracks generate from the defect areas and propagate along the {124} faces due to their lower binding energy under a proper temperature gradient, contributing to the total transcrystalline fracture. It is confirmed that the generation and development of the voids in the crystal grains can be developed when unmatched dimensions of the two opposite faces are formed. And the development of the voids is dependent on the dimensions and orientations of the two opposite faces.