Binding Energy Of 2p Electrons Research Articles

Alloying and oxidation of in situ produced core-shell Al@Yb nanoalloy particles--an "on-the-fly" study.

Core-shell-structured nanoalloy particles with an Al-dominated interior covered by few Yb monolayers have been fabricated using a vapor-aggregation method involving magnetron sputtering. The radially segregated structure of the Yb-Al nanoparticles has been disclosed by "on-the-fly" photoelectron spectroscopy monitoring of the nanoparticle beam in Yb 4f and Al 2p electron binding energy regions. Both, the binding energy values and the electron microscopy images taken on the deposited nanoparticles, allow estimating their dimensions to be in the 5-10 nm range. The photoelectron spectroscopy results suggest that in these nanoparticles no trivalent Yb--the typical case for the macroscopic Yb-Al alloy--is present. The oxidation of preformed Yb-Al nanoparticles was successfully attempted, leading to the appearance of divalent Yb surface oxide--in contrast to the bulk macroscopic Yb which is trivalent in the oxide. Our results suggest that at intermediate oxygen exposures "sandwich-like" nanoparticles of YbO/Yb/Al were synthesized. At higher O2 exposures, the oxygen seems to penetrate all the way to the Yb-Al interface. The results of the present study have to be considered when photonic applications of Yb-doped garnet nanoparticles are planned.

Synchrotron-based photoelectron spectroscopy provides evidence for a molecular bond between calcium and mineralizing organic phases in invertebrate calcareous skeletons

Organic compounds have been extracted from calcium carbonate skeletons produced by three invertebrate species belonging to distinct phyla. The soluble parts of these skeleton matrices were isolated and analysed by synchrotron-based X-ray spectroscopy (XPS). The presence of calcium associated with these organic materials was revealed in every sample studied, with important variations in Ca 2p binding energy from species to species. Measured Ca 2p binding energy values are more related to compositional diversity of the mineralizing matrices of the skeletons, whose taxonomic dependence has long been established, than to the Ca carbonate polymorph selected to build the skeletal units. This suggests a physical bond between species-specific mineralizing organic assemblages and the associated calcium. Remarkably, the binding energy of 2p electrons in calcium associated with mineralizing matrices is consistently higher than Ca 2p values obtained in purely mineral carbonate (both calcite and aragonite). The ability both to identify and measure the effect of organic matrices on their mineral counterpart in calcareous biominerals opens a new perspective for a functional approach to the biomineralization process.

Binding energy of 2p-electrons of silicon atom. Substituents effects in Si-centered cation-radicals

The substituent effect was analyzed on the binding energy of 2p-electrons of the silicon atoms estimated by the X-ray electron spectroscopy or calculated by quantum chemistry method for 15 series of organosilicon compounds. It was established for the first time that the binding energy depended not only on the inductive and resonance effects of the substituents, but also on the polarization effect consisting in the electrostatic interaction of the positive charge on the silicon atom with the dipoles which this charge induced in the substituents. The contribution of the polarization effect reached 35%.

Large variations in the propensity of aqueous oxychlorine anions for the solution/vapor interface

Core-level photoelectron spectroscopy measurements have been performed of aqueous solutions of NaCl codissolved with NaClO(n) (n=1-4). Each species has a distinct Cl 2p electron binding energy, which can be exploited for depth-profiling experiments to study the competition between Cl(-) and ClO(n)(-) anions for residing in the outermost layers of the solution/vapor interface. Strongest propensity for the surface is observed for n=4 (perchlorate), followed by n=3 (chlorate), n=2 (chlorite), n=0 (chloride), and n=1 (hypochlorite). Molecular dynamics simulations rationalize the greatest surface propensity of the most oxidized anions in terms of their larger size and polarizability. The anomalous behavior of hypochlorite, being less surface-active than chloride, although it is both larger and more polarizable, is suggested to arise from the charge asymmetry over the anion, increasing its efficiency for bulk solvation.

Dilution effects on optical absorption and core-level photoelectron spectra of BaTiO 3 mesocrystals

Dilution effects such as increases of the optical absorption energy and of the Ti 2p and Ba 3d electron binding energies from those of BaTiO 3 bulk were observed for BaTiO 3 mesocrystals fabricated by soaking MCM-41 molecular sieve to precursor solutions with various concentrations and calcination in flowing oxygen at 700°C. For the mesocrystals, the optical absorption energy increased from 3.0 2 to 3.3 5 eV with decreasing the precursor concentration. The Ti 2p 3/2 electron binding energy of the mesocrystals was larger than the bulk one (456.9 eV), and increased from 457.5 to 458.7 eV with decreasing the precursor concentration. An increase in the Ti 2p electron binding energy corresponds to the increase of the optical absorption energy for the mesocrystals from lower concentration precursors. The Ba 3d 5/2 electron binding energy of the mesocrystals was also larger than the bulk one (777.1 eV), though it remained at 780.0 eV in spite of variation in the precursor concentration.

The air-exposed surface of sputter deposited silicon carbide studied by x-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy analysis of the air-exposed surface of sputter deposited amorphous silicon carbide films shows three dominant features: (1) Si–C bonding characteristic of SiC, with Si 2p electron binding energy at 100.4–100.7 eV and C 1s electron binding energy at 282.7–283.2 eV, (2) Si–O bonding characteristic of SiO2, with Si 2p electron binding energy at 102.1–102.5 eV, O 1s electron binding energy at 532.0 eV, and the O 1s-Si 2p electron binding energy difference equal to 429.5–429.9 eV, and (3) a strong adventitious C signal. The spectral features are consistent with a model for the surface of SiC powder consisting of several monolayers of hydrocarbons over several nm of SiO2 that overlays the bulk SiC. The oxidation behavior of the film surface was found to depend upon the cathode voltage at which the film was deposited.

Characterization of surfaces of amorphous NiFeP alloys

The surface of amorphous and crystallized Ni 80− x Fe x P 20 alloys containing 0–80 at.% iron was studied in comparison with crystalline NiFe alloys by X-ray photoelectron spectroscopy after mechanical polishing in cyclohexane at room temperature and after heat treatment of the mechanically polished specimen in hydrogen gas of 1 MPa at 500 K. The binding energies of P 2p, Fe 2 p 3 2 and Ni 2 p 3 2 electrons of the metallic state in the alloys changed linearly with the ratio of the atomic fraction of metallic iron to the sum of atomic fractions of metallic iron and nickel in the alloy surface immediately under the surface film. In the NiFeP alloys, the electron transfer from Fe and Ni to P occurred since the P 2p electron binding energy in the alloys smaller than in red phosphorus and the Ni 2 p 3 2 and Fe 2 p 3 2 electron binding energies in the alloys are larger than those in nickel and iron metals. During polishing in cyclohexane, the iron-concentrated surface films were formed on both the amorphous and crystalline alloys, and the contents of anionic species in the surface films changed with compositions of both alloys. These surfaces were hydrogen-reduced and then shortly exposed to air. The surface films formed on the hydrogen-reduced amorphous alloys contained exclusively iron ions as cations and a large amount of OH − and some phosphate as anions, and were significantly thicker indicating a high reactivity of the hydrogen-reduced amorphous alloy surface, while the hydrogen-reduced crystalline NiFe alloys were covered by thin, protective surface films.

An ESCA study of organosilicon compounds

Abstract The silicon 2p electron binding energies have been measured for a series of 33 organosilicon compounds. The binding energies are correlated with partial atomic charges calculated by various electronegativity models and CNDO calculations. Group shifts are reported for various chemical groups attached to silicon and are found to correlate with group shifts reported for carbon and phosphorus compounds.

X-ray photoelectron spectroscopic studies of some iodine compounds

A number of iodine compounds are studied as solids, in particular some iodine-oxygen and iodine-chlorine compounds and the tri-iodide ion. The chlorine 2p electron binding energy for I2Cl6 can be resolved into two peaks of intensity ratio 2:1 corresponding to terminal and bridging chlorine atoms. The iodine 3d electron binding energy for the tri-iodide ion may be resolved into peaks corresponding to different iodine atoms. The experimental results are compared with CNDO calculations, using both a 5s, 5p(sp model) and a 5s, 5p and 5d(spd model) basis set, in the framework of the ground and relaxation potential models (GPM and RPM). The CNDO calculations (spd model) give good agreement with previously published charges for xenon compounds, and the spd model, but not the sp model, is found to give good agreement with the experimental results for iodine compounds. The RPM model is found to be an improvement over the GPM model. The overall bond orders obtained with the spd model charges and charges based on Pauling electronegativities are compared for the isoelectronic series SiO4–4, PO3–4, SO2–4, ClO–4, and the trends found to be in the opposite directions. For ClO–4, Pauling charges give particularly poor agreement with experiment.

Complex halides of the transition metals. Part XIV. The X-ray photoelectron spectra of mononuclear and dinuclear complex halides of rhenium(III) and rhenium(IV), and of the Re(NCS)6 2? and Re2(NCS)8 2? complex anions

Rhenium 4f and chlorine 2p electron binding energies have been recorded for a series of complex halides of rhenium in the formal oxidation states +4 and +3. Referencing the rhenium 4f7//2 level to a standard chlorine 2p value provides a guide to the metal oxidation state and allows a ‘correction’ to be made for small variations in Madelung potential within a series of salts of a particular complex halide (e.g., Re2Cl82–). Both bridging and terminal rhenium-chlorine atoms have been distinguished in the [Re2Cl9]– and [Re2Cl9]2– anions. Little variation in rhenium 4f binding energies was observed for a series of anions of the type [ReCl5,L]–. The rhenium 4f binding energies of the Re(NCS)62– and Re2(NCS)82– anions are also reported together with the nitrogen 1s and sulphur 2p levels of the pseudohalide ligand molecules.

Phosphorus 2p electron binding energies. Correlation with extended Hueckel charges

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhosphorus 2p electron binding energies. Correlation with extended Hueckel chargesM. Pelavin, D. N. Hendrickson, J. M. Hollander, and W. L. JollyCite this: J. Phys. Chem. 1970, 74, 5, 1116–1121Publication Date (Print):March 1, 1970Publication History Published online1 May 2002Published inissue 1 March 1970https://doi.org/10.1021/j100700a027RIGHTS & PERMISSIONSArticle Views825Altmetric-Citations202LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (697 KB) Get e-Alerts