Analysis Of Solid Surfaces By Soft X-Ray Appearance Potential Spectroscopy

Abstract

The total soft x-ray emission of an electron-bombarded surface exhibits abrupt changes at the threshold potentials for the excitation of core levels of surface atoms. These features represent the excitation probabilities of the core states superimposed on a smoothly increasing background and can be sensitively detected by differentiating the x-ray emission with respect to sample potential. The application of this technique to the study of surface composition, chemical shifts, and band structure is discussed.