Grain orientation distribution and development of grain line in highly ordered Bi4Si3O12 micro-crystals

Abstract

Bismuth silicate (Bi4Si3O12) micro-crystals with a grain line structure were grown by a sintering method under atmosphere pressure. The as-grown products were studied using Xray diffraction (XRD) and Environmental scanning electron microscopy (ESEM). The grain orientation law was tested by the One-Sample Kolmogorov-Smirnov (K-S) test. The result shows Bi4Si3O12 grains are always distributed in pairs on both sides of a stable line. On one side of a line, the angle between grain orientation and the growth direction of the line obeys the normal distribution. It indicates that the grains on one side have almost the same orientation. The range of mean angle on one side is from 53.9º to 68.9º in a stable line. There is a highly positive correlation between mean angle and mean growth rate on one side of a stable line. If a mean angle on one side exceeds the maximum mean angle of a stable line, the highly ordered structure on the opposite side will be destroyed. However, the elimination process on the destructed side has no effect on the highly ordered structure on the other side. There are two kinds of grain line creation. One originates from a defect on one side of a line, and the other originates from the boundary between neighboring lines.

Keywords

• Bi4Si3O12
• grain line
• orientation
• grain deviation angle
• creation and elimination