STRUCTURE IMPERFECTION OF GAMMA-AL2O3

摘要

The X-ray diffraction pattern of gamma-Al2O3 is found to be broadened with every diffraction line being different. This is attributed to the difference of regularity of oxygen ions and aluminium ions. In order to study the structural information shown by this selected broadening, the peak separation processing for the gamma-Al2O3 X-ray diffraction pattern has been carried out. It is found that the lattice distortion of gamma-Al2O3 can be neglected and the gamma-Al2O3 crystallite size is approximately isotropic. Therefore it might be deduced that the selective widening of the diffraction line does not come mainly from the anisotropy of the crystallite shape. According to our result that the diffraction line width with low index (220) is wider than that with high index (440) the selective widening of the diffraction line might come mainly from the structure defect. This implies the possibility of the existence of the stacking fault in the gamma-Al2O3 structure and it might be concluded that the diffraction line widening of the gamma-Al2O3 caused by the stacking fault leads to the crystalline structure imperfection. [References: 4]