Chemical state

About: Chemical state is a research topic. Over the lifetime, 2378 publications have been published within this topic receiving 78183 citations.

Adhesive-Adherend Bond Joint Characterization by Auger Electron Spectroscopy and Photoelectron Spectroscopy

Abstract: Chemical and physical information about intact adhesive bond joints is usually inferred from data obtained from each isolated component (adhesive and adherend) prior to bonding or after bond failure. A technique is presented in which the chemical state as well as the elemental distribution can be obtained from intact bond joints using conventional surface characterization techniques such as Auger electron and photoelectron spectroscopies. The technique involves the use of thin film adherend adhesively bonded structures. The thin film adherends (5×10-7m) are prepared by vacuum deposition, which, after various treatments and subsequent bonding, can be ion beam etched away until the adherend-adhesive interface is reached for characterization. A number of bonding parameters have been investigated using this technique, including effects of adherend surface treatments (i.e. anodization, protection primers, corrosion inhibitors) and cure conditions (i.e. time, temperature and pressure).

Chemical Effects in Kβ/Kα X-Ray Emission Intensities from First-Row Transition Element Compounds

Abstract: Chemical effects in x-rays that arise form core transitions are usually small and most investigations have concentrated on precise measurement of the shifts in energies of the peaks. For first-row transition elements perturbations in Kα12 Kβ′ and Kβ25 energies have been studied for many compounds. Changes in peak intensities have been much less thoroughly investigated, with the exception of I(Kβ′): I(Kβ13), (I=intensity) which can be roughly correlated with the number of unpaired 3d electrons1. A few years ago it was suggested 2 that relative peak intensities might be influenced by the chemical state (i.e. valence) and ligand environment of the emitting atom and that such information could then be used to investigate the chemical state of a radioactive recoil atom in a solid matrix provided that it decayed by electron capture which would be followed by x-ray emission. Chromium has such an isotope and the work reported there is part of a systmatic study of a wide range of chromium and vanadium compounds. Results using non-dispersive techniques have already been reported3 but the claim to have observed a clear variation of I(Cr Kβ):I(Cr Kα) with Cr valence has been disputed4.

The chemical state of arsenic in minerals of environmental interest--an XPS and an XAES study.

Abstract: A systematic analytical study using X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy (XAES) has been carried out to characterize the chemical state of arsenic in complex environmental samples. The conventional approach, which relies on the chemical shift of the core levels As3d, provides ambiguous results in determining the chemical environment of arsenic. A more accurate approach, based on the Auger parameter and on the Wagner (Chemical State) plot, which combines AsLMM kinetic energy and As3d binding energy, was adopted. This novel method for determining the chemical state of arsenic was employed to completely characterize arsenic in complex environmental samples.