Grain size trends and correlation analysis in highly ordered grain line structure of bismuth silicate (Bi4Si3O12) micro-crystals

Highly ordered bismuth silicate micro-crystals have been grown by sintering method at 800oC for the first time. The samples were characterized for structural and surface morphological properties by X-ray diffraction (XRD) and Environmental scanning electron microscopy (ESEM). The result shows that a pure cubic phase (Bi4Si3O12) was obtained. The Bi4Si3O12 grains always distribute in pairs on both sides and arrange grain lines. There are two types of grain size trend along with the growth direction of the grain line. One trend is gradually increased or decreased and the other trend is basically unchanged. In most cases the grain size trends on both sides of one line are approximately consistent and there is a highly positive correlation between the grain growth rates on both sides of one line. The highly positive correlation analysis indicates a relationship between grain growth rates on both sides, such as when the value for one grain growth rate increases, the value for the other grain growth rate in pairs also increases. If the grain size trends on both sides are thoroughly inconsistent and there is a nonlinear relationship between grain growth rates on both sides in one line, these two trends may belong to two types respectively.