Topic
Chemical state
About: Chemical state is a research topic. Over the lifetime, 2378 publications have been published within this topic receiving 78183 citations.
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01 Jan 1994
TL;DR: In this paper, the authors showed that the copper films with 0.5keV and 10keV argon ion irradiation have strong adhesion, but the adhesion of the copper film with 5.5 and 10.1k V argon ions was lower than that of the ones with no irradiation.
Abstract: We have prepared copper thin films on polyimide films by evaporation of copper metal and simultaneous irradiation of argon ions with energies in the range of 0.5 to 10keV. The argon ion density irradiated at the interface between the copper thin film and the substrate was changed from 5×10 14 to 5×10 16 ions/cm 2 in each ion energy range. The adhesion of copper films was evaluated by means of peel strength. The copper films prepared with 0.5keV argon ions have strong adhesion, but the adhesion of copper films with 5keV and 10keV argon ions was lower than that of copper films prepared without argon ion irradiation. The chemical states of the polyimide film surface and the chemical binding states at the interlayer were evaluated by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometry. The film surface was carbonized by argon ion bombardment, and the carbonization was promoted with the increase of ion energy. The carbonization caused the decrease of the copper film adhesion. The adhesion didn't depend on the chemical binding states at the interlayer. It is consider that the increase of the adhesion was attributed to the anchor effect caused by the diffusion of copper atoms into the substrate by argon ion bombardment.
TL;DR: In this article, the authors used nondestructive-depth profiling of non-Pd coated FeTi samples along with interfacial information from Pd-FeTi specimens to obtain unique insight into the decomposition process.
Abstract: FeTi is considered an excellent candidate for the reversible storage of hydrogen and has been studied extensively in an attempt to understand the bulk activation needed for this material before use. Segregation of TiO 2 to the surface has been noted to occur during activation explaining a slight loss of efficiency per hydride cycle, however, characterization by a host of bulk and surface sensitive techniques has not revealed the cause of this decomposition process. 10 nm FeTi samples were prepared in a UHV evaporator both with and without palladium coatings. Post treatment characterization was performed with backscatter c onversion e lectron M ossbauer s pectroscopy (CEMS), XPS and SIMS. CEMS is a powerful tool for providing stoichiometric, electronic, magnetic, chemical, and particle size information of iron at depths down to 100 nm. XPS and SIMS are useful to gain quantitative and chemical state information from the topmost 2 nm and the topmost monolayer, respectively. Activation treatments consisted of annealing at 573K and 623K followed by reduction at 573K. Results indicate that ppm levels of H 2 O in H 2 are sufficient to decompose the FeTi alloy and produce TiO 2 and Fe metal domains at the surface. Also, at 573K in vacuum, a solid-state reaction was found to occur between Fe oxides and FeTi to produce Fe metal and TiO 2 . The Pd-FeTi interface was probed with CEMS and the results demonstrate hydrogen dissociation and migration in the absence of alloy decomposition. Our approach uses nondestructive-depth profiling of non-Pd coated FeTi samples along with interfacial information from Pd-FeTi specimens to obtain unique insight into the decomposition process.
31 Dec 2015
TL;DR: In this article, the influence of the surface chemical state and the oxygen vacancies on the atomic and electronic structure of the nanowires was studied. But the results were limited to a few nanometers of tin suboxides.
Abstract: Wire-like crystals of tin dioxide were synthesized by a gas-transport technique. The wires, of mainly nanometric diameters, were characterized by spectroscopy and microscopy techniques with the use of highly brilliant and intense synchrotron radiation. We studied the influence of the surface chemical state and the oxygen vacancies on the atomic and electronic structure of the nanowires. The surface of the nanowires is covered by a few nanometers of tin suboxides. The lack of oxygen over the surface layers leads to specific sub-zone formation in a gap, as shown by synchrotron studies.
TL;DR: In this paper, the relative kinetic energies of photoelectron and Auger peaks from the same element in XPS, the Auger parameter, provides unique chemical information on the top 10 nm of the surface.
Abstract: Comparison of the relative kinetic energies of photoelectron and Auger peaks from the same element in XPS, the Auger parameter, provides unique chemical information on the top 10 nm of the surface. The Auger parameter is related directly to the extra atomic relaxation and polarization energies of the element, as presented in a chemical state plot. Previous Auger parameter studies (Wagner 1975; West & Castle 1982) have assumed a homogeneous concentration and chemical state for each element; however, in many surface analysis applications the distributions are not perfectly uniform and conventional Auger parameter analysis is not suitable.
01 Jul 2017
TL;DR: In this article, a standardless EDX analysis method was proposed to identify the chemical state composition for an unknown sample, which can be easily achieved by a certain data processing, and the layers composition on Cu substrate, which was consisting of CuO and CuiO.
Abstract: TEMJEDX analysis techniques are widely used in failure analysis. Based on TEM results, one can know the structures of the sample e.g. in anomalous or crystalline, as well as the thickness of the thin film layer. Typically, TEM/EDX results can only provide the elemental information of the sample. In this paper, we discussed a standardless EDX analysis method to identify the chemical state composition for an unknown sample. Generally, it is to use the atomic percentage Wia' (excluding Pt from the sample preparation), which can be easily achieved by a certain data processing, to identify the chemical state composition. For example, in this paper, we studied the layers composition on Cu substrate, which was consisting of CuO and CuiO.