The influence of inter-atomic transitions in Auger valence band spectroscopy: oxygen on Si(001)2 × 1

Abstract

In this paper we will show that the description of an Auger process in terms of a process confined to one atom is in general not adequate and the Mulliken population is only in very specific cases a good alternative in evaluating the strength of inter-atomic transitions.The ionicity of the chemical bond cannot be used as a direct measure of the contribution of inter-atomic Auger transitions, as will be demonstrated in the case of the oxygen KW Auger transitions in gaseous molecular oxygen and oxygen chemisorbed on the Si(OO1) surface. A full evaluation of inter-atomic transition rates shows that their strength depends on the inter-atomic distance as well as on the screening of the initial core hole.

Impact of interatomic electronic decay processes on Xe 4d hole decay in the xenon fluorides

“…Finally, by combining the population factors from Table I and the transition strengths from Table II, the par- 6 , the contribution from IAED to the total Xe 4d decay width drops monotonically, consistent with the one-center picture mentioned in Sec. I.…”

“…12 Matthew and Komninos 13 were the first to present a formal examination of interatomic Auger processes. Using strong approximations, 6 they concluded Note that due to spin-orbit coupling and ligand-field effects, the Xe 4d orbitals are not all equivalent.…”

Interaction of atomic oxygen (N2O) with a clean Si(001) surface: O adsorption geometries as derived from the O KVV Auger lineshape

“…A change in core state is in general accompanied by relaxation processes which, due to their complex impact, are still not well understood [17]. According to our calculations [13] a relaxation of the core state wavefunction also influences the intensity ratio LY for the 0 Auger transitions, Considering these aspects, it is obvious that the simple chemical bond ionicity concept of Weissmann [4] has only a very limited application. Since the probabili~ of inter-atomic Auger electron emission processes depends sensitively on the degree of the overlap of the oxygen wavefunctions with the silicon wavefunctions 1131, the question arises if (Y can be assigned to a specific 0 adso~tion geometry.…”

“…These experiments should be accompanied by a theoretical calculation of the 0 KLL Auger Iineshapes in which the electron distribution, extending as far as nn and next nn atoms surrounding the oxygen atom and the core hole at this oxygen atom, is explicitly taken into account. An investigation into the influence of a specific adsorption geometry on the core state wavefunction by means of the MNDO quantum chemical cluster approach [13] is not feasible. For that purpose an ab initio method is required.…”

Anomalous Natural Linewidth in the2pPhotoelectron Spectrum ofSiF4

“…Since the interatomic rates scale as the 6th power of this distance, it is possible that these effects could be important in SiF 4 . We investigate this possibility using the expression given by Matthew and Komninos. Since this expression has been subject to some criticism [13], we first test it on a problem that has been studied by Zobeley et al [5], the interatomic rate in a neon-argon dimer with an initial hole in the neon 2s shell. This decays to a state with one hole in the neon 2p shell and one in the argon 3p shell.…”