[en] The 4s- and 4p- XPS spectra of Xe gas, XeF₂ molecule and XeF₄ molecule are calculated by an ab-initio atomic many-body theory. The 4s-peak and the prominent '4p'-peak are predicted well by the present theory. In XeF₂ and XeF₄ the spectral lines observed below the 4d-double ionization threshold are the 4d^-24f multiplet states strongly perturbed by the interaction with the initial 4p_1/2-hole state. They are very similar to the spectral lines which emerge with an increase in atomic number (e.g. Ba)

[en] The valence hole created by the L2-L3 M45 Coster-Kronig (CK) transition may hop away from the ionized atomic site before the L3-hole decays. Then when the third (Auger) electron emitted by the L3-hole decay is measured in coincidence with the photoelectron emitted by the initial L2-level electron ionization, the coincidence spectrum becomes similar or identical to the singles spectrum of the secondary (Auger) electron emitted by the L3-hole decay as if it decayed as an initial single core hole. Thus the coincidence spectrum is essentially governed by the valence-hole dynamics of both the intermediate states and the final states of the L2-L3 (M45) CK-transition preceded Auger transition. In the present paper the Auger-photoelectron coincidence spectroscopy (APECS) spectra of Fe, Co, and Ni metals reported by C.P. Lund et al. (Phys. Rev. B55 (1997) 5455) are analyzed in light of the delocalization and localization of the valence hole(s) created by the CK transition or the CK-transition preceded Auger transition

[en] The singles L23-M45M45 Auger-electron spectroscopy (AES) spectrum of early 3d-transition metal can be fitted by a weighted sum of the density of the single-hole states and that of the two-hole states, broadened by the initial L23-hole lifetime width, respectively (in the present paper we denote the atomic shells Lx, My, and Nz by LX, MY and NZ, respectively). With increasing occupancy of the 3d band the probability of creating the two-hole states by the L23-M45M45 Auger transition and the L2-L3M45 Coster-Kronig (CK) transition increases. However, the M45 hole created by the CK transition is delocalized and becomes decoupled (screened out) from the L3-hole decay so that the L3M45 two-hole state 'decays' to the single L3-hole state before the L3-hole decays. Thus the singles AES spectrum by the L2-L3-M45(M45) CK-transition preceded Auger transition and the singles one by the L3-M45(M45) Auger-transition overlap. We can study the M45-hole dynamics by Auger-photoelectron coincidence spectroscopy because the coincidence spectral lineshape depends on the dynamics of the M45 hole created by the CK transition

[en] Using the charge transfer (CT) core-hole screening model we analyzed the photoelectron-photoion coincidence spectroscopy (PEPICS) spectra of the O⁺ ion desorption from TiO₂(1 1 0) surface measured in coincidence with the Ti or O core-electron photoemission. The present theory predicts well the ratio of the PEPICS spectral intensity measured in coincidence with the Ti core photoelectron spectroscopy (PES) satellite to that with the Ti core PES main line. In contrast to the Knotek and Feibelman (KF) mechanism the three localized O 2p holes created by CT Ti core-hole screening outlast the desorption so that the O⁺ ion desorbs from TiO₂(1 1 0) surface upon the Ti core-electron ionization. The O 1s PES satellite creates three localized O holes by the O KV-L₁VV spectator Auger decay, while the O 1s PES main line creates three localized O holes by the O K-VVV and K-L₁VV Auger shakeup decay. As the Auger shakeup decay is very small compared to the spectator Auger decay, the O⁺ ion desorption yield in coincidence with the O 1s PES shakeup satellite is much enhanced compared to that with the O 1s PES main line.

[en] The 3p-hole lifetime widths of atomic and metallic Zn are calculated by an ab-initio atomic many-body theory. The frozen-core extended random-phase approximation with exchange (RPAE) using the atomic (super) Coster-Kronig (CK)-electron kinetic energy predicts well the atomic widths, whereas the same approximation using the metallic (s)CK-electron kinetic energy overestimates the metallic lifetime widths. The use of the orbitals relaxed in an ionic state together with the extended RPAE and metallic (s)CK-electron kinetic energy can predict well the metallic lifetime widths. The atomic and metallic lifetime widths are analyzed in detail. Why an ab-initio atomic many-body theory often works so well for metallic (solid-state) spectra is discussed in light of the change in the initial core-hole self-energy from free atom to metal

[en] From an analysis of the M₄₅ X-ray photoelectron spectroscopy (XPS) spectrum and the singles M₄₅-N₄₅N₄₅ Auger-electron spectroscopy (AES) spectrum of Pd metal, it has been known that the M₄-M₅N₄₅ Coster-Kronig (CK) transition is energetically disallowed in Pd metal. However, the M₄₅-N₄₅N₄₅ Auger-photoelectron coincidence spectroscopy (APECS) spectrum measured in coincidence with the M₄ photoelectron line shows that the M₄-M₅N₄₅ CK transition is not significantly quenched in metallic Pd. The present analysis of the APECS spectrum using a many-body theory shows that the N₄₅ hole created by the CK transition is delocalized before the M₅ hole decays. Thus, the M₄-M₅N₄₅-N₄₅N₄₅N₄₅ CK transition preceded Auger transitions should be interpreted as the M₄-M₅-N₄₅N₄₅ transition. The CK transition rate of metallic Pd is as large as 0.32 eV, comparable to that in Rh

[en] The first theoretical study of the effect of the final-state interaction on the initial core-hole lifetime is presented. The 4s-hole lifetime width of Sn metal is calculated by an ab-initio atomic many-body theory (Green's function method). When the final-state interaction in the 4p4d two-hole state, created by the 4s^-1-4p^-14d^-1 εf super Coster-Kronig (CK) transition of the initial 4s hole, is explicitly taken into account, the ab-initio atomic many-body calculation of the 4s-hole X-ray photoelectron spectroscopy (XPS) spectrum of Sn atom can provide excellent agreement with experiment in both the 4s-hole energy and the 4s-hole lifetime width. Otherwise, the many-body calculation underestimates considerably the 4s-hole lifetime width. The 4p4d two-hole state interacts strongly with the 4d triple-hole state by the 4p^-14d^-1-4d^-3 εf super CK transition. The interaction affects greatly the initial 4s-hole lifetime width

[en] The satellite in the M₄₅-N₄₅N₄₅ Auger-photoelectron coincidence spectroscopy (APECS) spectrum of metallic Sn (Z=50) measured in coincidence with the M₄ photoelectron line was interpreted as due to the M₄-M₅N₄₅-N₄₅N₄₅N₄₅ Coster-Kronig (CK) transition preceded transition. However the M₄-M₅N₄₅ CK transition is energetically not allowed in metallic Sn. We interpret the satellite as due to the M₄-M₅-N₄₅N₄₅ Auger transition, in which the M₄ hole traps it own screening electron and a secondary electron is ejected into the continuum from the M₅ level. The transition rate is 0.12-0.15 eV. When the M₄₅-N₄₅N₄₅ APECS spectrum was measured in coincidence with the M₅ photoelectron line using non-monochromatic Mg Kα X-ray line, the electron analyzer set on the M₅ photoelectron line, detected also the M₄ photoelectrons excited by the Mg Kα₃ X-ray line. The satellite ('Mg Kα₃ satellite') in the M₄₅-N₄₅N₄₅ APECS spectrum is interpreted as due to the M₄-N₄₅N₄₅ Auger transition of the M₄ hole created by the Mg Kα₃ X-ray line. However, we consider that the satellite is predominantly a bandlike two-hole state by the M₅-N₄₅N₄₅ Auger transition

[en] Highlights: → The M_4,5-N_2,3N_2,3 Auger-electron spectroscopy (AES) spectrum of atomic Sn is calculated by an ab initio atomic diagramatic perturbation theory. → The AES spectrum is entirely smeared out and in good agreement with experiment. → It shows the complete breakdown of the quasi-particle picture of the two N_2,3 holes by the N_2,3N_2,3-N_4,5N_4,5N_4,5N_4,5 and N_2,3N_2,3-N_2,3N_4,5N_4,5 super Coster-Kronig (sCK) transitions. → By measuring the M_4,5 photoelectron spectroscopy (PES) spectrum in coincidence with the M_4,5-N_2,3N_2,3 Auger decay one can detect the missing M_4,5-N_2,3N_2,3 AES lines. - Abstract: The M_4,5-N_2,3N_2,3 Auger-electron spectroscopy (AES) spectrum of atomic Sn is calculated by an ab initio atomic diagramatic perturbation theory, i.e., the extended frozen core random phase approximation with exchange (RPAE) . The AES spectrum is entirely smeared out and in good agreement with the experimental M_4,5-N_2,3N_2,3 AES spectrum of metallic Sn showing no discernible structure. It shows the complete breakdown of the quasi-particle picture of the two N_2,3 holes by the N_2,3N_2,3-N_4,5N_4,5N_4,5N_4,5 and N_2,3N_2,3-N_2,3N_4,5N_4,5 super Coster-Kronig (sCK) transitions. The present theory shows that one should be able to detect the missing M_4,5-N_2,3N_2,3 AES lines by measuring the M_4,5 photoelectron spectroscopy (PES) spectrum in coincidence with the M_4,5-N_2,3N_2,3 Auger decay. The lifetime width of the two N_2,3 holes is much larger than the effective Coulomb hole-hole interaction energy U between the two N_2,3 holes so that the multiplet coupling between the two N_2,3 holes breaks down. This is analogous to the case when U between two holes created in valence band states is much smaller (or larger) than the bandwidth, the two holes are delocalized (or localized).

[en] We discuss the effects of Coster-Kronig (CK) fluctuations and decay on the X-ray photoelectron spectroscopy (XPS) spectra of several atomic levels of the elements 20≤Z≤92, where Z is the atomic number. The spectral variations with atomic number are analyzed in light of how the real part (CK fluctuation) and imaginary part (CK decay) of the initial core hole self-energy due to the CK transition change with atomic number. The initial core-hole spectral function (XPS core-hole spectrum) is governed by the unperturbed initial core-hole energy, i.e., the relativistic Hartree-Fock ΔSCF core-hole energy, relative to the 'zero-point' energy at which the real part of the initial core-hole self-energy due to the CK fluctuation becomes zero and, at the same time, the imaginary part by the CK decay (approximately) maximizes. The 'zero-point' energy relative to the CK double-ionization threshold depends critically on the effective particle-hole interaction energy (or the polarization) in the two-hole one-particle state created by the CK transition of the initial core-hole. The present analysis of the XPS core-hole spectrum based on the 'zero-point' energy of the initial core-hole self-energy provides a unified picture of the screening and decay of an atomic-like localized hole. We explain why the ab-initio atomic many-body theory works well for solid-state XPS spectra. We discuss the correlation between the residual energy shift and the lifetime width. We also discuss the effect on core-hole spectra of the (super) CK transition involving an open subshell