Electron diffraction and microscopy studies of the structure of grain boundaries in silicon

Abstract

The diffraction effects expected from the periodic structure of twist boundaries in Si are determined by an examination of the reciprocal lattice of these boundaries. Methods of analysis are developed to distinguish between the real diffraction spots due to the periodic boundary structure and those due to double diffraction effects. The electron microscope images from the boundaries studied in Si bicrystals were frequently found to be complex and contained moiré fringes which provided no information on the actual boundary structure. By analysing the electron diffraction patterns from these boundaries for the presence of new diffraction spots it is possible to show that all the Σ1 [001], Σ1 [111] and Σ3 [111] twist boundaries examined have a periodic structure.