共查询到20条相似文献,搜索用时 46 毫秒
1.
Cu 2p, Cu 3d and O 1s electron spectra and Cu L3M4,5M4,5 Auger electron spectra from Cu, Cu2O and CuO have been studied at 25°C and at 400°C. The height of the Cu 2p satellite peaks from copper oxides was lowered when the temperature was raised. The intensity of the satellites also decreased if the sample stayed in vacuum for prolonged periods.Two commercial cuprous oxides were different with respect to the behaviour of the satellite peaks. One produced very weak satellites, while the other produced strong ones as previously reported in the literature for cuprous oxide. The colour of the oxides was slightly different, indicating that the stoichiometry was not the same.The change in satellite intensity is accompanied by changes in oxygen spectra, Cu L3M4,5 M4,5 Auger spectra and valence band spectra.It is useful to study Auger electrons in addition to the direct electron spectrum, since Auger signals can be more sensitive to surface conditions than direct electron spectra. 相似文献
2.
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
3.
Experimental angular emission profiles of the M2,3M4,5M4,562 eV Cu Auger electrons from clean copper (100) and (111) surfaces in several azimuths are presented. A simple single scattering theory to account for elastic scattering of the Auger electrons by other ion cores in the solid is presented, and calculations have been performed to assess the importance of this process in contributing to the observed angular dependence. These calculations produce angular structure having a similar magnitude and temperature dependence to that observed experimentally, and some featural similarity in peak positions or shapes. It appears that elastic scattering is an important source of angular dependence, and that studies of adsorbed species on surfaces should provide a very sensitive method of surface structure determination. 相似文献
4.
《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
5.
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
6.
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
7.
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
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.
《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
10.
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
11.
L3VV Auger transitions of copper alloys show a feature due to a band-like states, the shape and intensity of which depend on
the composition. The energy separation between this feature and the L3M4·5M4·5 peak increases progressively with Cu concentration. 相似文献
12.
W. Mehlhorn W. Schmitz D. Stalherm Dipl.-Phys. 《Zeitschrift für Physik A Hadrons and Nuclei》1972,252(5):399-411
The possibility of studying correlation effects through Auger electron spectrometry has been shown recently by Krause, Carlson and Moddeman in the case of theK Auger spectrum of neon. As a further example we have measured theM 4,5 Auger spectrum of krypton with high resolution. Correlation effects have been found via the strong deviations of relative intensities of Auger diagram lines (e.g.M 4,5 N 1 N 2,3(1 p 1)) from theoretical values and via the occurence of double Auger transitions, where one electron is emitted and another is excited. A critical examination of high resolution Auger spectra of noble gases, which has been measured so far, has shown that several non diagram lines can be assigned to double Auger transitions of the above kind. 相似文献
13.
14.
B.A. Sexton T.D. Smith J.V. Sanders 《Journal of Electron Spectroscopy and Related Phenomena》1985,35(1):27-43
Copper-exchanged sodium- A, X and Y zeolites have been characterized with X-ray photoelectron Spectroscopy (XPS), with supporting electron microscopy and X-ray diffraction measurements. Under reducing conditions (CO, H2, 250–450° C), four distinct chemical states of copper have been identified. These are intrazeolite Cu(II), Cu(I) and 1 nm metal clusters, and externally segregated copper metal crystallites. We report spectroscopic data for both the Cu 2p and Auger L3M4,5M4,5 lines. Whereas Cu(II) and metallic copper crystallites have normal spectroscopic parameters, Cu(I) and 1 nm Cu clusters in the reduced zeolites lie in new areas of the two-dimensional chemical state plot.The reduction sequence of Cu(II), Cu(I), Cu clusters and Cu crystallites is different on the A zeolite compared with X and Y. One nm metal clusters are identified as an intermediate phase on the A with transmission electron microscopy (TEM) and XPS prior to external diffusion and crystallite formation. The ease of formation of the cluster intermediate in the A zeolite may be a consequence of the larger diffusion barrier imposed by the 0.42nm supercage aperture compared with the 0.74nm aperture in the X and Y zeolites. 相似文献
15.
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
16.
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
17.
《Journal of Electron Spectroscopy and Related Phenomena》1998,95(1):1-24
The low-energy electron spectrum from the 57Co decay has been examined in the region from 0 up to 15 keV at instrumental resolution ranging from 2 to 15 eV. Two electrostatic spectrometers and radioactive sources prepared by vacuum evaporation of 57Co onto Al foils were utilized. Relative intensities of the main spectrum components have been obtained as follows: (TSE+LLX+Shake-off)/LMM/KLL/KLM/KMM/K−14.4/L−14.4/MN−14.4=116±12/51±4/59.7±1.8/15.2±0.4/1.15±0.07/49.6±1.5/5.05±0.15/0.79±0.02 where TSE means “true secondary electrons”. Absolute and relative energies of the LMM, KLL, KLM, and KMM Auger transitions in Fe have also been determined, as well as their relative intensities with the exception of the LMM lines, the shapes of which were strongly distorted due to the inelastic electron scattering and probably also chemical effects. From the measured conversion electron lines of the 14.4 keV M1 transition in 57Fe, a transition energy of 14412.8±0.8 eV and the E2 admixture less than 8×10−6 were derived. Relative intensities of both the KL2,3(M4,5N1) Auger line group and the M4,5N1−14.4 conversion line were found to be lower by about 30% for the “oxide” state of decaying 57Co atoms than for the “metallic” state. Pronounced broadenings of narrow spectrum lines have been observed as a consequence of the oxidation of the 57Co sources in the laboratory atmosphere. Natural widths for most of the KLL, KLM, and KMM Auger lines and those of the K, L1, L2, L3, M1, M2, M3 and N1 atomic levels in 57Fe were also determined. 相似文献
18.
《Journal of Electron Spectroscopy and Related Phenomena》1987,43(3):233-241
The Auger electron appearance potential spectra (AEAPS) of M4,5 levels of lanthanum in the elemental state and in LaH3 are presented. AEAPS measures the total differential secondary electron yield from the surface constituents as a function of incident electron energy. In the presence of a 3d hole, the 4f level is pulled down below the Fermi energy, EF. In the metallic La spectrum this is seen as a shoulder on the low energy side of the main peak, but in the LaH3 spectrum this shoulder disappears and is replaced by two peaks, again on the low energy side. The high binding energy satellite reported in the M5 level XPS spectra in La insulating compounds has been attributed to the lowering of the 4f level above the ligand band. Since no high binding energy satellite is observed in the M4,5 level AEAPS of LaH3, the lowest energy peak is assigned as the transition of the 3d electron to the 4f level pulled down below the hydrogen induced band. The other peak is related to the partially filled hydrogen induced band below EF. Tentative energy level diagrams for these transitions are proposed. 相似文献
19.
The Al Kα excited M4,5N4,5N4,5 Auger spectrum of Ba has been measured from the metallic sample evaporated on a Ag substrate. The spectrum has been decomposed into individual line components after the background subtraction. The decomposed spectrum has been compared with the theoretical spectrum calculated for the 4d?2 final state configuration in the mixed coupling scheme applying jj-coupling for the initial state and intermediate coupling for the final state. The most prominent structure of the spectrum shows the two 4d-hole coupling, but the structure which is caused by the Auger transitions M,45N2,3V has also been observed. The screening of the core holes in Ba metal seems to be produced by (5d6s) electrons. The simple excited atom model HF-calculations give an Auger kinetic energy shift (metal-free atom) of 16.7 eV, which is comparable to the experimental value 14–18 eV. 相似文献
20.
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