Electron energy loss spectroscopic investigation of Ni metal and NiO before and after surface reduction by Ar+ bombardment

X‐ray photoelectron spectroscopic chemical state quantification of mixed nickel metal, oxide and hydroxide systems

“…[24] Recent work on oxide films grown by exposure to only O 2 suggests that this peak is likely to be due to defective sites within the NiO structure. [22] Other references concur with this assignment [8] including results from nuclear reaction analyses (NRA) that rule out the possibility of Ni(OH) 2 or NiOOH. [22] A small peak at 532.8 eV (±0.1 eV, FWHM constrained to that of the defective site peak at 531.1 eV) may be due to adsorbed water or possibly adsorbed O 2 .…”

“…A major O 1s peak, approximately 30% of the total O 1s spectral area, at the binding energy of 531.1 eV (±0.04-eV FWHM ≈1.5 eV for both pass energies) has been proposed to be due to defective sites within the oxide crystal, [8,21,22] adsorbed oxygen, [23] or hydroxide species. [24] Recent work on oxide films grown by exposure to only O 2 suggests that this peak is likely to be due to defective sites within the NiO structure.…”

“…Ni(OH) 2 and NiOOH were found to fit reasonably to the multiplet line shape initially calculated for the free ions by Gupta and Sen. [9,10] NiO, which shows a well-resolved set of peaks, could only be satisfactorily fitted with the Gupta and Sen line shape by allowing variation in the binding energy positions of the multiplet contributions. For all three compounds, a broad peak associated with other intrinsic losses at a higher binding energy than the main peak multiplets, must be added to model the valley between the main peak and the satellite structures as is consistent with the inter-band losses attributed by Hagelin-Weaver et al [8,11] Roberts and Smart [12] have investigated changes in the defect structure of NiO due to heat treatment. A peak at 856.1 eV, detectable through the application of shallow takeoff angle analysis, was attributed to the presence of Ni(III).…”

“…Plasmon loss features must be included in any quantitative analysis that includes metallic Ni. Analysis of EELS [8] and REELS [7] data has been used to assign the surface and bulk plasmons within the Ni metal 2p XPS spectrum. Ni(OH) 2 and NiOOH were found to fit reasonably to the multiplet line shape initially calculated for the free ions by Gupta and Sen. [9,10] NiO, which shows a well-resolved set of peaks, could only be satisfactorily fitted with the Gupta and Sen line shape by allowing variation in the binding energy positions of the multiplet contributions.…”

Effect of phosphorus concentration on the electronic structure of nanocrystalline electrodeposited Ni–P alloys: an XPS and XAES investigation

“…a lower binding energy and thus the appearance of the satellite. An alternative explanation of the 6 eV satellite in nickel given in recent work based on reflection electron energy loss spectroscopy (REELS) [33] and energy loss spectroscopy (ELS) work [34] is to assign it to surface plasmon and shake-up losses. The ejected photoelectron passing through the solid could lead to a collective excitation of the conduction electrons, resulting in a characteristic energy loss, thus to plasmons.…”