The effect of interface roughness on the intensity profiles of Bragg peaks from superlattices

Abstract

We have derived an expression for the structure factor of a superlattice with ‘‘rough’’ interfaces, i.e., with random variations in the thicknesses of the layers. Our expression allows the determination of x-ray diffraction profiles in both radial (θ-2θ) and rocking scans. We have shown that the rocking curve of the central peak is essentially unaffected by this kind of disorder; and we have calculated the rocking curve widths of the satellites as a function of roughness. The implications of our model for the use of satellite/central peak intensity ratios as a measure of superlattice perfection are discussed.