共查询到20条相似文献,搜索用时 31 毫秒
1.
Gunnar Schön 《Journal of Electron Spectroscopy and Related Phenomena》1973,1(4):377-387
Part of the LMM Auger spectrum from metallic copper has been studied in a high resolution X-ray photoelectron spectrometer. Fine structure not earlier reported has been observed. The main L3M4,5M4,5 peak is very narrow, 1.0 eV, although the valence band is involved in the transition. The agreement between experimental and calculated Auger electron energies is very good. Since fine structure is found to be an intrinsic property in Auger spectra the interpretation of “satellite” peaks as due to electron—plasmon interactions should be used with care. The L3M4,5M4,5 peak is very sensitive to the copper surface conditions. Surface oxygen affects the peak in a characteristic way. 相似文献
2.
X-ray photoelectron spectra of the 2p levels of Co, Ni, and Cu compounds are examined concurrently with their L3M4,5M4,5 Auger spectra. A correlation is established between the presence or absence of Auger satellites with the presence or absence of photoelectron shake-up satellites for Co and Ni compounds. The correlation is less clear for cupric compounds. We propose the mechanism of Auger shake-up as a plausible interpretation for the observed behavior of these Auger satellites. 相似文献
3.
S. Aksela M. Kellokumpu M. Harkoma 《Journal of Electron Spectroscopy and Related Phenomena》1983,32(2):177-187
L2,3M4,5M4,5 Auger electron spectra of Zn and Cu have been measured in molecular ZnCl2 and (CuCl) 3 vapours. The spectra have been analyzed and compared with the corresponding free-atom spectra. It is found that the main features of the spectra are atomic-like. The energies are shifted by 0.55 eV in ZnCl2 and by 3.2 eV in (CuCl)3 towards higher kinetic energy compared with the corresponding free-atom spectra. For the intensity ratios between the L3 and L2 groups, the values 2.8 and 3.7 are obtained for Zn and Cu, respectively. These intensity ratio, together with energy considerations based on free-atom Dirac—Fock calculations and observed Auger shifts, indicate that the L2L3M4,5 Coster—Kronig process is energetically possible in (CuCl)3 molecular clusters but not in ZnCl2. The satellite structure in the spectra studied also supports this conclusion. 相似文献
4.
Experimental L3-M4,5M4,5 Auger spectra of metallic Cu and Zn show distinct characteristics of free-atom spectra but do not reflect the band structure. This quasi-atomic phenomenon in solids is tentatively explained as electron localization due to increased screening. 相似文献
5.
Seppo Aksela 《Journal of Electron Spectroscopy and Related Phenomena》1981,24(1):91-94
The kinetic-energy shifts between atomic and solid-state L3M4,5M4,5 Auger electron spectra of Cu, Zn, Ga, Ge, As, and Se are determined with the aid of semiempirically calculated atomic and experimental solid-state Auger energies. The shift values are calculated by applying the thermochemical model to the Auger process. Good agreement is found between the calculated and experimental values. 相似文献
6.
《Journal of Electron Spectroscopy and Related Phenomena》1988,46(1):93-102
The Ge:L2MM Auger electron spectra excited by Mg Kα X-rays from Ge(CH3)4 free molecules have been compared with the corresponding spectra excited by Al Kα X-rays. The Al Kα excited spectra have characteristic features of the diagram Auger transitions, because the excitation energy is far above the L2 ionization threshold. The energy of Mg Kα photons is 1.21 eV below the Ge:L2 ionization threshold and thus the Mg Kα excited L2MM Auger electron spectra indicate many-body effects, post collision interaction (PCI) effects and spectator Auger satellite structures. The L2M4,5M4,5 type spectrum displays both these features but the L2M2,3M4,5 type spectrum has only a spectator Auger satellite structure, because the (3p−13d−1nl) final state interferes with the (3s) hole state. 相似文献
7.
《Journal of Electron Spectroscopy and Related Phenomena》2005,148(2):107-114
KLL Auger spectra excited by electrons with energies in the 30–35 keV range of Fe, Cu and Ge films were measured, using thin free-standing films. It was possible to obtain spectra with an energy resolution of about 1 eV. The observed spectra can not be described satisfactorily by just the multiplet splitting of the final state as calculated for an isolated atom. Additional features, due in part to intrinsic (shake satellites) and in part to extrinsic (energy loss of the escaping electron) processes formed a large fraction on the observed intensities. In particular a number of distinct satellite structures that are not predicted by the atomic Auger process are observed. For Fe and Cu the satellite peaks can be explained in terms of shake-up processes from the 3d5/2–4d5/2 states. Similar satellite structures observed in Ge are partly attributed to plasmon creation and partly to shake-up processes. It is demonstrated that both the thickness dependence of the observed intensity distributions and transmission electron energy loss measurements contain invaluable information for the interpretation of these spectra. 相似文献
8.
Auger spectra have been recorded from elements of the first transition series using a hemispherical analyser. Highly resolved LMM spectra were obtained showing for the first time the composite nature of these peaks for many of the elements studied. The recorded spectra show a general similarity for the elements Sc → Zn but interesting differences emerge. At the beginning of the transition period the L3 based transitions have the relative intensities L3 M2,3, M2,3 > L3 M2,3, M4,5<> L3 M4,5, M4,5 whereas towards the end of the series the order L3 M4,5, M4,5 > L3 M2,3, M4,5<> L3 M2,3, M2,3 is observed. Pronounced chemical shifts have been observed upon oxidation. The spectra are interpreted in terms of an L -S coupling scheme and the fine structure discussed in terms of effects produced by multiplet splitting. 相似文献
9.
M. Romand M. Roubin J.P. Deloume 《Journal of Electron Spectroscopy and Related Phenomena》1978,13(3):229-242
Photoelectron and Auger spectra have been obtained for the copper and silver selenides CuSe, Cu 2Se, Ag 2Se, and AgCuSe as well as from CuS, Ag 2O, Ag 2S, Cu, and Ag. Binding-energy values, chemical shifts, and peak-shapes are reported for the Cu 3 d, Ag 4 d and Se 3 p electrons. Absence of multiplet splitting and shake-up structure is discussed in relation to the magnetic properties. It is shown that chemical shifts are much better revealed in the Auger spectra (Cu L3M4,5M4, 5 and Ag M5N4, 5N4, 5) than in the direct photoelectron ones. In addition the use of the Auger parameter to characterize the series under study is emphasized. Finally the valence-band spectra have been examined and the electronic structures are interpreted. 相似文献
10.
11.
Measurements of the zinc L2,3M4,5M4,5 Auger spectra are reported. The line shapes in solid zinc are similar to those in zinc vapour but the Auger energies have increased by about 15 eV and the line breadths have broadened from 0.5 eV to 1.0 eV fwhm. The ratio of the L2:L3 groups differ from the vapour suggesting that L2L3M4,5 Coster-Kronig transitions occur in the solid but not in the vapour. Changes in the spectra with oxidation have been observed. The Auger lines broaden on oxidation and a line breadth of 3.2 eV fwhm gives the best fit to the spectrum of almost fully oxidised zinc. The oxide L3M4,5M4,51G4 peak progressively shifts from 2.6 eV to 4.2 eV below the metal peak as the oxide thickness increases, the latter value being close to the measured shift in crystalline zinc oxide. Similar energy variation is reported for solid Argon condensed onto clean silver and the shifts are explained in terms of variation in “extra electron relaxation” with film thickness. 相似文献
12.
D’Addato et al. [S. D’Addato, P. Luches, R. Gotter, L. Floreano, D. Cvetko, A. Morgante, A. Newton, D. Martin, P. Unsworth, P. Weightman, Surf. Rev. Lett. 9 (2002) 709] studied the variation with Fe coverages in the relative Fe L3-M4,5M4,5 Auger electron spectroscopy (AES) spectral satellite intensity of ultrathin Fe films grown on Cu(1 0 0) by sweeping photon excitation energy through the Fe L2-level ionization threshold. They interpreted that the M4,5 hole in the L3M4,5 double-hole state created by the L2-L3M4,5 Coster–Kronig (CK) decay remains localized for longer than the L3-hole lifetime for the 0.3 and 10 ML coverages but has a lifetime comparable to the L3-hole lifetime for the 1 ML coverages. The present many-body theory shows that when the M4,5 hole created either by the CK decay or by the L3M4,5 shakeoff hops away from the ionized atomic site and becomes completely screened out prior to the L3-hole decay, the Fe L2-L3M4,5-L3-M4,5M4,5 AES main line as well as the Fe L3 M4,5 (satellite)-L3-M4,5M4,5 one, both of which are identical in line shape to the Fe L3-M4,5M4,5 one, dominate in the Fe CK preceded AES spectrum. The present analysis shows that the delocalization time of the M4,5 hole created in the 1 ML Fe/Cu(1 0 0) system by the L2-L3M4,5 CK decay is much shorter than the L3-hole lifetime so that the Fe L3-M4,5M4,5 AES spectral line shape hardly changes, except for the presence of a very weak spectator L2-L3M4,5-M4,5M4,5M4,5 AES satellite, when the photon excitation energy is swept through the Fe L2-level ionization threshold. For the 0.3 ML coverages the M4,5-hole delocalization time is still shorter than the L3-hole lifetime. 相似文献
13.
S. A. Novikov Ya. S. Akop’yan A. G. Kochur M. E. Vasil’eva 《Optics and Spectroscopy》2002,93(3):389-391
L 2, 3 Auger spectra of all argon-like molecules (HCl, H2S, PH3, SiH4) have been calculated with inclusion of the multiple ionization satellites. The Auger transition probabilities were calculated with inclusion of the ligand electron density, multiplet splitting, final-state configuration interaction, and spin-orbit splitting of the initial 2p level. The theoretical integrated intensities of the shake-off and shake-up satellites (“with a spectator”) in the L 2, 3 Auger spectra of argon-like molecules make up 8.2–10.4% of the total Auger spectrum intensity. 相似文献
14.
15.
N.G. Fazleev M.P. Nadesalingam W. Maddox S. Mukherjee K. Rajeshwar 《Surface science》2010,604(1):32-37
Changes in the surface of an oxidized Cu(1 0 0) single crystal resulting from vacuum annealing have been investigated using positron annihilation induced Auger electron spectroscopy (PAES). PAES measurements show a large increase in the intensity of the annihilation induced Cu M2,3VV Auger peak as the sample is subjected to a series of isochronal anneals in vacuum up to annealing temperature 300 °C. The intensity then decreases monotonically as the annealing temperature is increased to ∼600 °C. Experimental probabilities of annihilation of surface-trapped positrons with Cu 3p and O 1s core-level electrons are estimated from the measured intensities of the positron annihilation induced Cu M2,3VV and O KLL Auger transitions. Experimental PAES results are analyzed by performing calculations of positron surface states and annihilation probabilities of surface-trapped positrons with relevant core electrons taking into account the charge redistribution at the surface, surface reconstructions, and electron-positron correlations effects. The effects of oxygen adsorption on localization of positron surface state wave function and annihilation characteristics are also analyzed. Possible explanation is proposed for the observed behavior of the intensity of positron annihilation induced Cu M2,3VV and O KLL Auger peaks and probabilities of annihilation of surface-trapped positrons with Cu 3p and O 1s core-level electrons with changes of the annealing temperature. 相似文献
16.
Auger electron spectra of clean Mg and Fe surfaces have been investigated under UHV conditions. The main Auger peaks in the low energy Auger spectra of these elements are identified as due to L2,3VV and M2,3VV transitions for Mg and Fe respectively. Changes in the low energy spectra of these clean surfaces of Mg and Fe due to chemisorption of residual oxygen in the UHV system, were also studied. The results indicate that for each oxidised surface new larger Auger peaks appear at energies lower than the original main peaks in the clean spectra. The changes in the spectra are believed to be due to the energy shifts of inner energy levels and valence bands involved in the Auger transitions as an oxide is formed. 相似文献
17.
《Journal of Electron Spectroscopy and Related Phenomena》1999,98(2-3):129-133
Titanium nitride thin films were deposited on monocrystalline silicon (mc-Si) substrates by direct current reactive magnetron sputtering. Auger electron spectra (AES) of deposited films at different nitrogen partial pressures, show the typical N KL23L23 and Ti L3M23M23 Auger transition overlapping. Also, changes in the Ti L3M23M45 Auger transition peak are observed. X-ray diffraction and high resolution electron microscopy (HRTEM) of a golden color TiN/mc-Si sample, reveal a preferential polycrystalline columnar growth in the 〈111〉 orientation. This sample was also analyzed by electron energy-loss spectroscopy (EELS). The N/Ti elemental ratio is slightly different to the value determined by AES. Atomic distribution around the N atoms is in agreement with that expected from the N atom in the fcc unit cell of TiN. This distribution was obtained via an extended energy-loss fine structure (EXELFS) analysis from EELS spectra. 相似文献
18.
J.M. Lee R.E. Wood W.H. Wiser 《Journal of Electron Spectroscopy and Related Phenomena》1977,12(4):493-500
Two anolomous peaks in the ZnL3M2,3M4,5 Auger electron spectra of dried and heated samples of ZnCl2-coal mixtures have been interpreted as indication of a Zn-coal bond formation. The peaks show a decrease from the normal 9.1 eV splitting for ZnCl2 alone to 4.2 eV for ZnCl2-coal mixtures. High volatile bituminous coals show this effect to a greater extent than either higher or lower rank coals. It is surmised that the side of this bond formation could coincide with the site of catalytic activity in the catalytic hydrogenation of coal in the presence of ZnCl2. 相似文献
19.
The L3M45M45 spectra of V and Cr do not exhibit free atom behavior, in sharp contrast to those of Cu and Zn. An energy difference parameter, Δ ?, derived entirely from observable energies, has been introduced to correlate with the extent of electron localization and free-atom behavior in Auger transitions. 相似文献
20.
《Applied Surface Science》1986,26(1):42-50
The Auger and electron energy loss spectra (EELS) of a grain boundary fracture plane of bicrystal molybdenum (32 wt.ppm oxygen) are compared with the spectra of pure and oxidized molybdenum. The Auger spectrum of the fracture surface contains molybdenum and oxygen peaks, and the Mo M4,5NN line coincides with that of the pure metal. The interfacial Auger transition peak is observed on the low energy side of the Mo N2,3VV Auger peak. Both AES and EELS spectra of the fracture plane are different from those of the oxidized molydenum. These results show that the segregated oxygen is bound to the grain boundary fracture plane as if it were adsorbed. 相似文献