Auger, zero-energy photoelectron, coincidence spectroscopy: Chemical-site-selective Auger electron spectroscopy

Abstract

The Auger electron spectrum associated with decay of a core-hole on the terminal nitrogen and that associated with the central nitrogen of nitrous oxide, N 2O, are obtained individually through the use of a coincidence technique. Specifically, each of the two Auger electron spectra is obtained by detection of Auger electrons in coincidence with near zero energy (threshold) photoelectrons at the respective ionization thresholds. These zero energy electrons serve to identify the core-ionization continuum associated with the different Auger electrons. The salient features of the experimental spectra are in good agreement with theoretical calculations. The low counting rate generally associated with coincidence experiments, especially in the gas phase, is not encountered because the low energy electrons are collected over a 4π solid angle. Also, velocity discrimination is accomplished by a spatial filter rather than by time-of-flight to utilize the maximum duty cycle of the synchrotron source. These data are believed to be the first examples of chemical-site-selective molecular Auger spectra.