A new tool for studying epitaxy and interfaces: The XPS searchlight effect

Abstract

Very recently, a phenomenon long known in angle-resolved x-ray photoelectron spectroscopy (XPS) has been reinterpreted. The new interpretation is that XPS peak intensities are enhanced at angles corresponding to axes connecting the photoemitting atom to its immediate neighboring atoms. These enhanced intensities thus identify the bond axes present near the surface. In this paper, examples are presented of the great power of this ‘‘XPS searchlight’’ effect as a new tool for studying epitaxy and interfaces.