Inner valence molecular orbitals and the structure of X-ray photoelectron spectra

Abstract

The effects of silver additive on the superconducting properties of YBa2Cu,,10,..,:Ag., for x = 0.1, 0.3, 0.6 and 1.2 are studied by measuring the real and imaginary components of the magnetic response in an AC field. The data are fitted to Bean's critical state model and are used to obtain the macroscopic critical current density. The magneticsusceptibilityand criticalcurrent density are found to dependon the silver content whereas T, remains essentially unchanged. For x = 1.2 the critical current density sharply increases below 77 K. The results suggest that the silver improves the properties of grain boundaries and enhances the intergranular coupling. The real part of the magnetic response is found to be a function of H.IH". where H' is the value of the field when the critical-state profile reaches the centre of the specimen.

An XPS study of interaction of neptunyl(V) in aqueous solution with goethite (?-FeOOH)

“…Indeed, from the uncertainty relationship DEDt~h/2p (where DE is the half-width of the level from which an electron was removed, Dt is the lifetime of the hole, and h is Planck's constant) it follows that, if the O2s level were atomic, the half-width of the O2s line would be smaller than that of the O1s line, which is not the case. The mechanism of formation of the fine structure of the spectra of different elements including lanthanides in the range of binding energies from 0 to 50 eV was systematically studied in our previous work [13]. We found that inner valence MOs can be effectively formed in this range under certain conditions.…”

“…Unfortunately, it is difficult to estimate quantitatively the relative intensity of this line and the number of weakly bound Fe3d electrons from the spectrum. The weak band at 12314 eV can be due to MO electrons of the carbonate anion CO 3 23 [13].…”

“…The structure of the OMO spectrum is mainly caused by interaction of the Fe3d,4s and O2p electrons, and the structure of IMO, by interaction of the Fe3d,4s and O2s electrons [13]. Since the electronic configuration of iron atom is {Ar}3d 6 4s 2 (where {Ar} is the electronic configuration of argon) and the photoeffect cross section of the Fe3d electrons is substantially higher than that of the O2p electrons [12], the Fe3d 5 photoelectrons of the Fe(III) ion in the ground state should make the major contribution to the intensity of the OMO line (Fig.…”

“…Among them are the relative line intensity of Fe3d and Np5f electrons negligibly involved in chemical bonding; relative binding energies of outer (OMO) and inner (IMO) valence molecular orbitals; multiplet splitting DE ms (eV) of inner electronic levels; parameters of fine structure caused by the dynamic effect; and relative energies DE sat (eV) of the shake-up satellites in the spectra of inner electrons [13,14]. These spectral parameters furnish rich information on the physicochemical state of iron and actinides on the sample surface.…”

Influence of the Localization of Ge Atoms within the Si(001)(4 × 2) Surface Layer on Semicore One-Electron States

“…15-50 eV) is usually well resolved and can be associated with the linear combinations of semicore AOs originating from closed (sub)shells. The latter, in contrast to valence AOs, in some cases can be combined to so-called internal MOs (IMOs) [11,12]. In the case of adsorption complexes, the formation of those IMOs can be monitored by the exaggerated binding energies of adatoms.…”