Evolution of correlated electron behavior from the surface to the bulk in SrxCa1-xVO3

2015 ◽  
Vol 1730 ◽  
Author(s):  
J. Laverock ◽  
B. Chen ◽  
J. Kuyyalil ◽  
R. P. Singh ◽  
G. Balakrishnan ◽  
...  
Keyword(s):  
Binding Energy ◽  
Emission Spectroscopy ◽  
Spectral Weight ◽  
Hubbard Band ◽  
X Ray ◽  
Surface Sensitivity ◽  
Surface Component ◽  
Lower Binding Energy ◽  
Correlated Electron ◽  
Lower Hubbard Band

ABSTRACTWe present a detailed depth-sensitive study of the evolution in correlated electron behavior from the surface of the prototypical correlated oxide, SrxCa1-xVO3, to its bulk. Photoemission measurements of varying surface sensitivity are employed to directly compare both the spectral weight and energetics of the correlated electron features, and resonant soft x-ray emission spectroscopy is used as a bulk-sensitive reference. The surface component, which still contributes significantly to photoemission at 2.2 keV, is characterized by a transfer of spectral weight into the incoherent lower Hubbard band and the corresponding shift of these states towards lower binding energy.

An X-ray photoelectron spectroscopic study of the interaction of oxygen and nitric oxide with aluminium

1978 ◽  
Vol 363 (1714) ◽  
pp. 403-424 ◽  
Keyword(s):  
Nitric Oxide ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Complete Removal ◽  
Oxide Thickness ◽  
Oxygen Adsorption ◽  
Binding Energies ◽  
Deconvolution Analysis ◽  
X Ray ◽  
Lower Binding Energy

The interaction of oxygen and nitric oxide with clean aluminium surfaces has been investigated by X-ray photoelectron spectroscopy. Studies have been in the main confined to the temperature range 80–290 K and pressure range 10 -6 –10 -2 Pa. The Al(2p) level is shown to exhibit a shifted component at a binding energy of ~ 74.5 eV after oxygen interaction at 80 K. A curve-fitting and deconvolution analysis of the shifted peak indicates that it is made up of two components, one at a binding energy of 74.0 eV and the other at 75.3 eV. The lower binding energy component (designated α ) develops preferentially at 80 K while the higher binding energy one ( β ), assigned to Al 2 O 3 , is dominant at 290 K. We suggest that α is an incorporated oxygen structure which is a precursor to the formation of Al 2 O 3 . The initial sticking probability of oxygen at 80 K is 0.07 while at 290 K it is 0.02. The plasmon-loss features associated with the Al(2s) peak are shown to be sensitive to oxygen adsorption and therefore useful in confirming the surface monolayer. At 290 K and an oxygen pressure of 10 4 Pa the oxide thickness is estimated to be about 0.9 nm. When NO was adsorbed at 80 K three distinct N(1s) peaks were observed at binding energies of about 397, 403 and 407 eV. We assign the 397 eV peak to N δ- ads arising from dissociation of the molecule and the two higher binding energy peaks to N δ- ads and N 2 O ads . The N(1s) peak characteristic of NO δ- ads is close to the lower binding energy peak of the two N(1s) peaks associated with N 2 O ads while the O(1s) of NO δ- ads overlaps with the O(1s) peak of the surface oxide at a binding energy of about 532 eV. Mass spectroscopic analysis of the gas phase indicated that on warming to 85 K, the adlayer formed at 80 K, N 2 O was desorbed, confirming our assignment of the core-level spectra. The NO δ- and N 2 O species are not observed at 290 K while at 80 K exposure of the adlayer to water vapour results in the complete removal of weakly adsorbed N 2 O. By monitoring the intensities of the Al(2p), N(1s) and O(1s) peaks, estimates were made of the absolute and relative concentrations of the various species and various molecular processes delineated.

Signal/Noise Ratio and Elemental Detectivity by Eels

1982 ◽  
Vol 40 ◽  
pp. 488-489
Author(s):  
R. F. Egerton
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Elemental Analysis ◽  
Electron Energy Loss Spectroscopy ◽  
Emission Spectroscopy ◽  
X Ray ◽  
Signal Noise ◽  
Characteristic Signal ◽  
Noise Ratio ◽  
Electron Energy Loss

An important parameter governing the sensitivity and accuracy of elemental analysis by electron energy-loss spectroscopy (EELS) or by X-ray emission spectroscopy is the signal/noise ratio of the characteristic signal.

scholarly journals Phosphorus Kβ X-Ray emission spectroscopy detects non-covalent interactions of phosphate biomolecules in situ

2021 ◽  
Author(s):  
Zachary Mathe ◽  
Olivia McCubbin Stepanic ◽  
Sergey Peredkov ◽  
Serena DeBeer
Keyword(s):  
Nucleic Acids ◽  
Emission Spectroscopy ◽  
Adenine Nucleotides ◽  
X Ray ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Phosphate Groups

Phosphorus is ubiquitous in biochemistry, found in the phosphate groups of nucleic acids and the energy-transferring system of adenine nucleotides (e.g. ATP). Kβ X-ray emission spectroscopy (XES) at phosphorus has...

A DFT study of spherands containing five anisyl groups — Highly preorganized to bind the alkali metal

2006 ◽  
Vol 84 (8) ◽  
pp. 1045-1049 ◽  
Author(s):  
Shabaan AK Elroby ◽  
Kyu Hwan Lee ◽  
Seung Joo Cho ◽  
Alan Hinchliffe
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Density Functional ◽  
Ionic Radius ◽  
Binding Energies ◽  
Cavity Size ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Good Agreement

Although anisyl units are basically poor ligands for metal ions, the rigid placements of their oxygens during synthesis rather than during complexation are undoubtedly responsible for the enhanced binding and selectivity of the spherand. We used standard B3LYP/6-31G** (5d) density functional theory (DFT) to investigate the complexation between spherands containing five anisyl groups, with CH2–O–CH2 (2) and CH2–S–CH2 (3) units in an 18-membered macrocyclic ring, and the cationic guests (Li+, Na+, and K+). Our geometric structure results for spherands 1, 2, and 3 are in good agreement with the previously reported X-ray diffraction data. The absolute values of the binding energy of all the spherands are inversely proportional to the ionic radius of the guests. The results, taken as a whole, show that replacement of one anisyl group by CH2–O–CH2 (2) and CH2–S–CH2 (3) makes the cavity bigger and less preorganized. In addition, both the binding and specificity decrease for small ions. The spherands 2 and 3 appear beautifully preorganized to bind all guests, so it is not surprising that their binding energies are close to the parent spherand 1. Interestingly, there is a clear linear relation between the radius of the cavity and the binding energy (R2 = 0.999).Key words: spherands, preorganization, density functional theory, binding energy, cavity size.

scholarly journals Probing physical oxidation state via resonant X‐ray emission spectroscopy: Applications to iron model complexes and nitrogenase

2021 ◽  
Author(s):  
Serena DeBeer ◽  
Rebeca G. Castillo ◽  
Anselm W. Hahn ◽  
Benjamin E. Van Kuiken ◽  
Justin T. Henthorn
Keyword(s):  
Oxidation State ◽  
Emission Spectroscopy ◽  
Model Complexes ◽  
X Ray

scholarly journals Arsenoplatin-Ferritin Nanocage: Structure and Cytotoxicity

2021 ◽  
Vol 22 (4) ◽  
pp. 1874
Author(s):  
Giarita Ferraro ◽  
Alessandro Pratesi ◽  
Damiano Cirri ◽  
Paola Imbimbo ◽  
Daria Maria Monti ◽  
...  
Keyword(s):  
Biological Activity ◽  
Diffraction Data ◽  
Inductively Coupled Plasma ◽  
Emission Spectroscopy ◽  
Atomic Emission ◽  
Side Chain ◽  
Plasma Atomic Emission ◽  
Average Amount ◽  
X Ray ◽  
Inductively Coupled

Arsenoplatin-1 (AP-1), the prototype of a novel class of metallodrugs containing a PtAs(OH)2 core, was encapsulated within the apoferritin (AFt) nanocage. UV-Vis absorption spectroscopy and inductively coupled plasma-atomic emission spectroscopy measurements confirmed metallodrug encapsulation and allowed us to determine the average amount of AP-1 trapped inside the cage. The X-ray structure of AP-1-encapsulated AFt was solved at 1.50 Å. Diffraction data revealed that an AP-1 fragment coordinates the side chain of a His residue. The biological activity of AP-1-loaded AFt was comparatively tested on a few representative cancer and non-cancer cell lines. Even though the presence of the cage reduces the overall cytotoxicity of AP-1, it improves its selectivity towards cancer cells.

Potential‐Induced Spin Changes in Fe/N/C Electrocatalysts Assessed by In Situ X‐ray Emission Spectroscopy

2021 ◽  
Author(s):  
Viktoriia A. Saveleva ◽  
Kathrin Ebner ◽  
Lingmei Ni ◽  
Grigory Smolentsev ◽  
Daniel Klose ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
X Ray

Analysis of nitrogen distribution in iron-titanium alloys after nitrogen trapping in liquid lithium by using soft X-ray emission spectroscopy

2021 ◽  
Vol 170 ◽  
pp. 112548
Author(s):  
Ryo Omura ◽  
Juro Yagi ◽  
Keisuke Mukai ◽  
Makoto Oyaidzu ◽  
Kentaro Ochiai ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Emission Spectroscopy ◽  
Liquid Lithium ◽  
Nitrogen Distribution ◽  
X Ray

Study of buried interfaces in Fe/Si multilayer by hard x‐ray emission spectroscopy

2021 ◽  
Author(s):  
Hina Verma ◽  
Karine Le Guen ◽  
Renaud Delaunay ◽  
Iyas Ismail ◽  
Vita Ilakovac ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
X Ray ◽  
Buried Interfaces
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