Final-state effects in the x-ray photoelectron spectra of cubic sodium-tungsten bronzes

Systematics in the X-ray photoelectron spectra (X. p. e. s.) of Ti, V, Cr, Mn and Nb oxides with the metal ion in different oxidation states as well as of related series of mono-, sesqui- and di-oxides of the first row transition metals have been investigated in detail. Core level binding energies, spin-orbit splittings and exchange splittings are found to exhibit interesting variations with the oxidation state of the metal or the nuclear charge The 3d binding energies of the monoxides show a proportionality to Goodenough’s ( R — R c ). Other aspects of interest in the study are the satellite structure and final state effects in the X. p. e. s. of the oxides, and identification of different valence states in oxides of the general formulae M n O 2 n -1 and M 3 O 4 . The nature of changes in the 3d bands of oxides under-going metal-insulator transitions is also indicated.

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Bismuth Ruthenium Oxides. Neutron Diffraction and Photoelectron Spectroscopic Study of Bi2Ru2O7 and Bi3Ru3O11

Australian Journal of Chemistry ◽

10.1071/ch9931897 ◽

1993 ◽

Vol 46 (12) ◽

pp. 1897 ◽

Cited By ~ 31

Author(s):

GR Facer ◽

MM Elcombe ◽

BJ Kennedy

Keyword(s):

Neutron Diffraction ◽

Surface Oxidation ◽

Rietveld Analysis ◽

Photoelectron Spectra ◽

Final State ◽

Mixed Valency ◽

X Ray ◽

Ruthenium Oxides ◽

Line Shapes ◽

Powder Neutron Diffraction Data

The structures of Bi3Ru3O11, a = 9.3050(2)Ǻ, Pn3, and Bi2Ru2O7, a = 10.2957(1)Ǻ, Fd3m, have been redetermined by Rietveld analysis of powder neutron diffraction data. For both compounds there is no evidence for appreciable oxygen non- stoichiometry . X-Ray photoelectron spectra of both compounds show unusual line shapes. In the case of Bi3Ru3O11 this is a result of the mixed valency and surface oxidation. In Bi2Ru2O7 final state effects appear to be important.

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IDENTIFICATION OF CONJUGATE ELECTRON TRANSITIONS IN X-RAY PHOTOELECTRON SPECTRA

Журнал структурной химии ◽

10.15372/jsc20170613 ◽

2017 ◽

Keyword(s):

Photoelectron Spectra ◽

X Ray ◽

Electron Transitions ◽

Conjugate Electron Transitions

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Modification of Wood with Monoethanolamino-borate by The Data of X-Ray Photoelectron Spectroscopy

MATEC Web of Conferences ◽

10.1051/matecconf/201819604005 ◽

2018 ◽

Vol 196 ◽

pp. 04005

Author(s):

Irina Stepina ◽

Irina Kotlyarova

Keyword(s):

Particle Size ◽

Photoelectron Spectroscopy ◽

Model Compound ◽

Hydrolytic Stability ◽

Photoelectron Spectra ◽

Wood Cellulose ◽

Rapid Loss ◽

X Ray ◽

Wood Protection ◽

Cellulose Materials

The difficulty of wood protection from biocorrosion and fire is due to the fact that modifiers in use are washed out from the surface of the substrate under the influence of environmental factors. This results in a rapid loss of the protective effect and other practically important wood characteristics caused by the modification. To solve this problem is the aim of our work. Here, monoethanolaminoborate is used as a modifier, where electron-donating nitrogen atom provides a coordination number equal to four to a boron atom, which determines the hydrolytic stability of the compounds formed. Alpha-cellulose ground mechanically to a particle size of 1 mm at most was used as a model compound for the modification. X-ray photoelectron spectra were recorded on the XSAM-800 spectrometer (Kratos, UK). Prolonged extraction of the modified samples preceded the registration of the photoelectron spectra to exclude the fixation of the modifier molecules unreacted with cellulose. As a result of the experiment, boron and nitrogen atoms were found in the modified substrate, which indicated the hydrolytic stability of the bonds formed between the modifier molecules and the substrate. Therefore monoethanolaminoborate can be considered as a non-extractable modifier for wood-cellulose materials.

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Fingerprinting shock-induced deformations via diffraction

Scientific Reports ◽

10.1038/s41598-021-88908-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Avanish Mishra ◽

Cody Kunka ◽

Marco J. Echeverria ◽

Rémi Dingreville ◽

Avinash M. Dongare

Keyword(s):

High Speed ◽

Shock Loading ◽

Dislocation Slip ◽

Line Profiles ◽

X Ray Diffraction ◽

Final State ◽

X Ray ◽

Shock Testing ◽

Local Pressures ◽

Deformation Modes

AbstractDuring the various stages of shock loading, many transient modes of deformation can activate and deactivate to affect the final state of a material. In order to fundamentally understand and optimize a shock response, researchers seek the ability to probe these modes in real-time and measure the microstructural evolutions with nanoscale resolution. Neither post-mortem analysis on recovered samples nor continuum-based methods during shock testing meet both requirements. High-speed diffraction offers a solution, but the interpretation of diffractograms suffers numerous debates and uncertainties. By atomistically simulating the shock, X-ray diffraction, and electron diffraction of three representative BCC and FCC metallic systems, we systematically isolated the characteristic fingerprints of salient deformation modes, such as dislocation slip (stacking faults), deformation twinning, and phase transformation as observed in experimental diffractograms. This study demonstrates how to use simulated diffractograms to connect the contributions from concurrent deformation modes to the evolutions of both 1D line profiles and 2D patterns for diffractograms from single crystals. Harnessing these fingerprints alongside information on local pressures and plasticity contributions facilitate the interpretation of shock experiments with cutting-edge resolution in both space and time.

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High-resolution cryo-EM structure of photosystem II reveals damage from high-dose electron beams

Communications Biology ◽

10.1038/s42003-021-01919-3 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Koji Kato ◽

Naoyuki Miyazaki ◽

Tasuku Hamaguchi ◽

Yoshiki Nakajima ◽

Fusamichi Akita ◽

...

Keyword(s):

Photosystem Ii ◽

Physiological State ◽

High Dose ◽

Final State ◽

X Ray ◽

Redox States ◽

X Ray Crystallography ◽

Cryo Electron Microscopy ◽

Redox Active ◽

Beam Damage

AbstractPhotosystem II (PSII) plays a key role in water-splitting and oxygen evolution. X-ray crystallography has revealed its atomic structure and some intermediate structures. However, these structures are in the crystalline state and its final state structure has not been solved. Here we analyzed the structure of PSII in solution at 1.95 Å resolution by single-particle cryo-electron microscopy (cryo-EM). The structure obtained is similar to the crystal structure, but a PsbY subunit was visible in the cryo-EM structure, indicating that it represents its physiological state more closely. Electron beam damage was observed at a high-dose in the regions that were easily affected by redox states, and reducing the beam dosage by reducing frames from 50 to 2 yielded a similar resolution but reduced the damage remarkably. This study will serve as a good indicator for determining damage-free cryo-EM structures of not only PSII but also all biological samples, especially redox-active metalloproteins.

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Impact of high temperatures on aluminoceladonite studied by Mössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopy

Mineralogy and Petrology ◽

10.1007/s00710-021-00753-z ◽

2021 ◽

Author(s):

Mariola Kądziołka-Gaweł ◽

Maria Czaja ◽

Mateusz Dulski ◽

Tomasz Krzykawski ◽

Magdalena Szubka

Keyword(s):

Photoelectron Spectroscopy ◽

Integral Intensity ◽

Photoelectron Spectra ◽

X Ray Diffraction ◽

Structural Reorganization ◽

Oh Groups ◽

X Ray ◽

Al Content ◽

Integral Intensity Ratio ◽

Higher Temperature

AbstractMössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopies were used to examine the effects of temperature on the structure of two aluminoceladonite samples. The process of oxidation of Fe2+ to Fe3+ ions started at about 350 °C for the sample richer in Al and at 300 °C for the sample somewhat lower Al-content. Mössbauer results show that this process may be associated with dehydroxylation or even initiate it. The first stage of dehydroxylation takes place at a temperature > 350 °C when the adjacent OH groups are replaced with a single residual oxygen atom. Up to ~500 °C, Fe ions do not migrate from cis-octahedra to trans-octahedra sites, but the coordination number of polyhedra changes from six to five. This temperature can be treated as the second stage of dehydroxylation. The temperature dependence on the integral intensity ratio between bands centered at ~590 and 705 cm−1 (I590/I705) clearly reflects the temperature at which six-coordinated polyhedra are transformed into five-coordinated polyhedra. X-ray photoelectron spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p and O1s core levels, highlighted a route to identify the position of Si, Al, K and Fe cations in a structure of layered silicates with temperature. All the measurements show that the sample with a higher aluminum content and a lower iron content in octahedral sites starts to undergo a structural reorganization at a relatively higher temperature than the less aluminum-rich sample does. This suggests that iron may perform an important role in the initiation of the dehydroxylation of aluminoceladonites.

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