Showing papers on "Chemical state published in 1979"
629 citations
TL;DR: In this article, the concentration profiles of oxide films on Si have been studied by using ESCA and ellipsometry, and the oxide films were found to be composed mostly of stoichiometric SiO 2 with a very thin (about 0.3 nm) layer of SiO at the SiSiO 2 interface.
153 citations
TL;DR: In this article, the authors analyzed the chemical states and the concentrations of Mg and Ni at the surface of the hydrogen storage materials MgMg2Ni eutectic alloy and Mg 2Ni intermetallic compound.
77 citations
TL;DR: In this paper, the feasibility of using pattern recognition and factor analysis to extract chemical state information from Auger line shapes was explored using x-ray-excited carbon Auger spectra.
Abstract: The feasibility of using pattern recognition and factor analysis to extract chemical state information from Auger line shapes was explored. These data analysis techniques were applied to x‐ray‐excited carbon Auger spectra. It was found that Auger line shapes could be described by using the amplitudes of selected frequencies from the Fourier‐transformed Auger spectrum as variables during the computations. Factors analysis was found to predict the length of the alkyl chain in a series of poly(alkyl methacrylate) spectra and also indicated a chemical state difference in carbonaceous residues on sheet steels exhibiting good corrosion resistance and poor corrosion resistance.
58 citations
25 citations
Journal Article•
01 Jan 1979-Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy
11 citations
10 citations
TL;DR: Using the technique of selected area Auger sampling, an examination has been made of the composition and contaminant state of (100) surfaces of indium phosphide as mentioned in this paper, and the chemical state of surfaces stored under various conditions and following cleaning with organic solvents or etching with hydrofluoric acid has been investigated.
Abstract: Using the technique of selected area Auger sampling, an examination has been made of the composition and contaminant state of (100) surfaces of indium phosphide. The chemical state of surfaces stored under various conditions and following cleaning with organic solvents or etching with hydrofluoric acid has also been investigated.
7 citations
TL;DR: In this paper, the use of combined surface analytical techniques such as X-ray Photoelectron Spectroscopy (XPS) or ESCA to probe the surfaces of diesel particulates is presented.
Abstract: Preliminary studies on the use of combined surface analytical techniques such as X-ray Photoelectron Spectroscopy (XPS or ESCA). Auger Electron Spectroscopy (AES), Secondary Ion Mass Spectrometry (SIMS) and Ion Scattering Spectrometry (ISS) to probe the surfaces of diesel particulates are presented. Studies of two different particulate systems are reported. Results of the first study show common chemical forms associated with the surface of particulate emission. Oxygen, sulfur and nitrogen in various chemical states are seen on the surface of a carbonaceous-graphitic (pyrolytic) center. These elements are postulated as organically bound surface segregated species. Observation of particles extracted for routine adsorbed organic analysis by gas chromatography show that nitrogen and sulfur compounds are left behind, along with residual organics. Trace metals were not seen on any sample. The second study involves samples collected under different running speed conditions of a diesel engine. Typical a...
5 citations
TL;DR: In this article, the authors used optical transmission, ESR, and wet chemical methods to determine concentration and the chemical state of silver, and NMR spectra as a probe of the glass structure.
Abstract: Interdiffusion of silver ions in SiO2-B2O3-AI2O3-R2O glasses where R=Na or K was investigated, using optical transmission, ESR, and wet chemical methods to determine concentration and the chemical state of silver, and NMR spectra as a probe of the glass structure. The concentration of silver introduced by ion exchange increased monotonically, as the line widths of27AI NMR spectra decreased. The sharp and narrow features of 27Al line shapes were broadened and the amount of colloidal silver produced by ion exchange decreased, as R2O/B2O3 approached unity with fixed AI2O3. The BO4 to BO3 ratio approached unity and the quadrupole coupling constant of BO3 units varied from 2.70 to 2.96 MHZ, as R2O/AI2O3, approached unity for fixed B2O3. These diverse data suggest a relation between silver diffusion and glass structure, although the phenomena of phase separation and the mixed-alkali effect could also influence silver-colloid formation in the glasses studied.
TL;DR: The chemisorption of oxygen on Ir(100) has been investigated under ultrahigh vacuum conditions with thermal desorption mass spectrometry (TDS), contact potential difference measurements, Auger electron spectroscopy, and LEED as discussed by the authors.
Abstract: The chemisorption of oxygen on Ir(100) has been investigated under ultrahigh vacuum conditions with thermal desorption mass spectrometry (TDS), contact potential difference measurements, Auger electron spectroscopy, and LEED. Oxygen may adsorb in three distinct chemical states: a molecularly chemisorbed species that is stable below 100 K, a dissociatively chemisorbed species, and a surface oxide that forms rapidly above 700 K.
01 Jan 1979
TL;DR: In this article, two-dimensional distributions, depth profiles and the chemical state of the segregation were investigated by IMMA (ARL), ESCA (V.G.) and XRF.
Abstract: It has been reported that several elements segregate on the surface of cold-rolled steel sheets during annealing in a hydrogen reducing atmosphere [1,2]. In the present report, two-dimensional distributions, depth-profiles and the chemical state of the segregation were investigated by IMMA (ARL), ESCA (V.G.) and XRF.
TL;DR: In this paper, the relative intensity distribution of the K? x-ray satellites arising from multiply ionized atoms was investigated and it was shown that the multiplet intensities are sensitive to the environment and are therefore capable of providing additional chemical information.
Abstract: High resolution x-ray spectrometry in combination with excitation by heavy-ion bombardment provides a number of prospective ways of obtaining information relating to the chemical state of a substance. The relative intensity distribution of the K? x-ray satellites arising from multiply ionized atoms is sensitive to the chemical environment and in some cases might be profitably employed to distinguish between various chemical species. At resolutions sufficient to discern features of the multiplet structure associated with the angular momentum coupling of unpaired electrons, it is found that the multiplet intensities are also sensitive to the environment and are therefore capable of providing additional chemical information. For elements below phosphorous in the periodic table, the K? satellites overlap the K absorption edge, thereby providing a convenient and accurate means of measuring K binding energies. In this way, chemical shifts equivalent to those obtained by ESCA may be determined.
TL;DR: In this article, the problem of nucleation at chemical instabilities is investigated by means of microscopic computer simulation, and the first-order transition of interest involves a new kind of nucleations arising from chemical transformations rather than physical forces.
Abstract: The problem of nucleation at chemical instabilities is investigated by means of microscopic computer simulation. The first-order transition of interest involves a new kind of nucleation arising from chemical transformations rather than physical forces. Here it is the chemical state of matter, and not matter itself, which is spatially localized to form the nucleus for transition between different chemical states. First, the concepts of chemical instability, nonequilibrium phase transition, and dissipative structure are reviewed briefly. Then recently developed methods of reactive molecular dynamics are used to study chemical nucleation in a simple model chemical reaction. Finally, the connection of these studies to nucleation and condensation processes involving physical and chemical interactions is explored.
TL;DR: In this article, CEMS was used to characterize the nitrided steel surfaces and chemical states of surfaces estimated layer-by-layer, and a 2.3 µm thickness of γ'2-Fe4N (magnetically randomly oriented), and distorted α-Fe layers.
Abstract: CEMS was used to characterize the nitrided steel surfaces and chemical states of surfaces estimated layer by layer. Gas nitrided steel surface is composed of e-Fe2N, distorted Fe3+xN (0≤x≤1), γ'-Fe4N martensite and α-Fe layer slightly disturbed by intruded nitrogen. Tufftrided steel surface consists of e-Fe3N, intermediate e-Fe3N and γ'-Fe4N, γ'-Fe4N and disturbed α-Fe layers. Ion nitrided steel surface has a 2~3 µm thickness of γ'2-Fe4N (magnetically randomly oriented), γ'2-Fe4N and distorted α-Fe layers.