Diffraction effects from interfaces

Abstract

The ability of electron microscopes to examine the structure and composition of materials on a very fine scale has paved the way for a renewed interest in examining the structure at interfaces and grain boundaries. Complemented by theoretical work on the structure of interfaces, much new information has become available. Among the various techniques available for studying the structure at interfaces, diffraction experiments have proved to be very useful. It has been shown, for example, that a periodic array of defects exists within the plane of the interface, leading to extra reflections in the plane of the interface. More recently, the diffraction behavior in the direction perpendicular to the interface plane has been examined. By considering diffraction effects in this direction only (to be referred to as the z direction in real space and the L direction in reciprocal space), information can be derived on the structural distortions in this direction near the interface without interference from any arrays of defects within the interface plane.