Electron spectroscopy using theory, x-ray absorption and resonant Auger techniques

Eric L. Shirley*
Sensor Science Division, National Institute of Standards and Technology**

A variety of theoretical methods treat electron excitation spectra (x-ray absorption, photoemission, Auger electron spectroscopy, or XAS, PES, AES). These include excited-state density-functional theory and the GW/Bethe-Salpeter (BSE) framework, real-space multiple-scattering methods, and the cumulant-based methodology meant to tackle satellites in spectra. Different methods treat different aspects of problems in physics and are also used in combination.

We first apply theoretical methods to glean insight from core-excitation spectra in lead titanate, lead tungstate and lithium peroxide, illustrating the methods’ role in helping identify crystal structures, including as a function of temperature and pressure.

We next turn to silver, where resonant AES can give insight into the unoccupied band states, allowing one to distill all dipole-allowed partial densities of states.

* Work done in collaboration with J.C. Woicik, C. Weiland, B. Ravel, and others.
** This work was supported in part by the U.S. Department of Energy