Comparison of x-ray absorption with x-ray photoemission of nickel dihalides and NiO

Speciation and Quantitative Mapping of Metal Species in Microbial Biofilms Using Scanning Transmission X-ray Microscopy

“…The spectra extracted from different regions of the Ni 2p image sequence were similar, and the stack fit analysis confirmed that there was only one major Ni species present in the biofilm. Comparison of the Ni spectrum derived from the biofilm with that recorded from NiO (Figure 4a) (the latter matches that in the literature (19)) indicates the Ni was in the Ni(II) oxidation state. Figure 4b presents the quantitative map of the spatial distribution of Ni in the biofilm, derived from an SVD analysis of the Ni 2p image sequence using as references the internal Ni spectrum, derived by threshold masking and placed on a linear absorption scale set by the long range NiO data, and the smoothed non-Ni spectrum extracted from a region with no detectable Ni.…”

“…Chan et al (7) used STXM to show that microbially generated iron-oxyhydroxide filaments contain polysaccharides, suggesting that the polysaccharides are the mineral structure-directing component. It is possible to deduce not only oxidation state but ligand arrangement, and, in some cases, ligand identity from details of the metal 2p NEXAFS fine structure (19)(20)(21). Pecher et al (22) used STXM and linear regression procedures to perform Mn speciation from selected areas on bacteria-produced nodules using the Mn 2p absorption edge.…”

X-ray Absorption Spectral Analyses by Theoretical Calculations for TiO2 and Ni-Doped TiO2 Thin Films on Glass Plates

“…According to a theoretical calculation introducing the manybody theory by van der Laan et al 20 and van Elp et al, 22 it has been reported that the large peak at 853 eV is assigned to the 2p -3/2 -3d 9 character and that the next peak at around 855 eV is assigned to 3d 9 L or hybrid ( 3d 9 and 3d 10 L -) characters. Also, the changes in the feature and position of the peak around 855 eV indicate that the spectral features are directly related to the oxidized form, or are reflected in multiplet splittings.…”

“…20,22,23 We must consider here that the L-edge spectra are profiled by the 2p spin-orbit interaction splitting, that is, the L3 (2p3/2) edge and the L2 (2p1/2) edge. Thus, the electron transitions of the L-edges were described as 2p3d n → 3d n+1 and 2p3d n L→2p -3d n+2 L -by taking the ligand-to-metal charge transfer into account, where and L -stand for the 2p core hole and holes in the ligand band, respectively.…”

“…12,16,17,[20][21][22][23][24] So far, nanocrystal TiO2 and Ni ions deposited on a SiO2 crystal have been studied by X-ray absorption experiments. 7,[25][26][27][28] However, TiO2 and Ni ion-doped TiO2 thin films on glasses have been little observed by similar experiments; in addition, the steric and electronic structures of Ti and Ni ions in the thin films on the glasses have not yet been discussed by theoretically analyzing the obtained spectra.…”