A study of a number of mixed transition metal oxide spinels using X-ray photoelectron spectroscopy

Surface composition of CoxNi1−xO solid solutions by X-ray photoelectron and Auger spectroscopies

“…Ni 3+ species in solid state oxides have generally been reported with binding energies approximately 1.5 eV higher than this value [32,33]. The data are, therefore, inconsistent with Ni 3+ as a dominant species in the near-surface region for the Co x Ni 1−x O solid solutions, regardless of composition.…”

“…The data are, therefore, inconsistent with Ni 3+ as a dominant species in the near-surface region for the Co x Ni 1−x O solid solutions, regardless of composition. Tetrahedrally coordinated Ni 2+ , for example in NiAl 3 O 4 [32,33] and NiCr 2 O 4 [34], has also been reported with binding energies 1-2 eV larger than those observed here. Therefore, even in the range of x = 0.6-0.7 where the spinel compound appears to be forming, the nickel species is predominantly octahedrally coordinated Ni 2+ .…”

Electrochemical Characteristics of Layered Li1.95Mn0.9Co0.15O3(C2/m) as a Lithium-Battery Cathode

“…Additionally, as shown in the inset of the figure, the spectra become more asymmetrical due to swelling toward lower binding energies. These observations indicate that the quantity of Mn 3+ in the active material increases as the number of cycles increases, 18 which is in agreement with the CV results. Figure 7 shows the XRD profiles of the as-prepared material and 5-and 10-cycled cathode samples in the potential range of 2.0-4.8 V at current densities of ±30 mAg −1 .…”

Effect of Mn substitution on the promoted formaldehyde oxidation over spinel ferrite: Catalyst characterization, performance and reaction mechanism

“…Compared to the Mn 2p XPS and TG-DSC results, the E of Mn 3s suggests the lower valence of Mn cations in ferrites. From previous studies [57,58], the presence of foreign cations in manganese oxides reduces the degree of Mn-O covalency and accordingly increases the Mn 3s splitting. Therefore, the decrease of E in this study is probably related to the presence of structural Fe cations.…”