| As a result of the decreasing size of nanocrystalline, its character changed simultaneously. Most studies are focused on the influence of grain boundaries, which plays an important role in the in the nanocrystalline. But less concern on the microstructure of the grain. Based on the other's theory, we calculate the influence of grain boundaries to the aberration of the crystal lattice. And conclude that there're two layers in the nanocrystalline grain. In the outer layer, the aberration of the crystal lattice is larger than in the inner layer, the closer to the grain boundary, the lager aberration is. But in the inner layer, the relation is unobserved. The aberration in these area is neglectable. By the use of X-ray diffraction, we testified the rationality of the layer structure in the nanocrystalline grain, and discussed the evolvement of the microstructure and the form of the vacancy. The most important, we had observed the layer structure by using of HRTEM, it's the most powerful evidence of the layer structure. |
