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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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TL;DR: In this paper, an ion beam and a radiofrequency plasma source are applied for surface treatment; a dicrect current (DC)-sputter process is used for the deposition.
Abstract: Next generation surface acoustic wave (SAW) devices require improved metallisations due to the demand of higher frequencies and power densities for new applications. Most likely, these metallisations will include adhesion or diffusion-barrier layers between the piezoelectric substrate and the electrode. For improved properties, the pre-treatment of the substrate and the chemical state of these layers is of great interest. This work gives an overview about studies of the effect of surface preparation at LiNbO3 substrates for Ta and Ti depositions and their different chemical reactions (oxidation) with the substrate surface. An ion beam and a radio-frequency plasma source are applied for surface treatment; a dicrect current (DC)-sputter process is used for the deposition. The characterisation of the surface's chemical changes is performed by XPS connected to a separate preparation chamber (quasi in situ) used for pre-cleaning and film deposition. The detailed chemical layer structures at the surfaces are determined by angle-resolved XPS and comparison with model calculations. In addition, atomic force microscope measurements are used to study the surface morphology showing almost no difference in surface roughness of the preparations. Copyright © 2014 John Wiley & Sons, Ltd.
11 citations
TL;DR: In this article, the authors analyzed the refractive index of the oxygen plasma anodised (OPA) film on Ge(111) is generally 1.66-1.68 ( lambda = 6328 AA).
Abstract: Anodisation of a germanium surface was carried out successfully in oxygen plasma excited by a high-frequency (500 kHz) electromagnetic field in a quartz reactor. The refractive index of the oxygen plasma anodised (OPA) film on Ge(111) is generally 1.66-1.68 ( lambda =6328 AA). The chemical composition and chemical states of the Ge-OPA film have been analysed using Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) with argon ion sputtering. There is GeO2 on the surface of the OPA film. In the bulk of the OPA film, there is mainly GeO2 and some unoxidised germanium. The distribution of O and Ge is fundamentally homogeneous in the bulk. There are double peaks for Ge(3d) in the XPS of the Ge-OPA film after argon ion sputtering. The binding energy of 32.7 eV is due to the Ge in GeO2, and that of 29.2 eV corresponds to a few unoxidised Ge atoms in the OPA film. The chemical stoichiometry of the OPA film is very similar to that of vitreous GeO2.
11 citations
TL;DR: In this paper, the possibilities of the CKVV Auger identification of sp2-sp3-bonds in CNx and CNxOy are shown, and the problems of the synthesis of C3N4 are the difficulties of the formation of stoichiometric compound and a monitoring of sp3bonds of carbon atoms as well.
11 citations
TL;DR: The spatial distribution of potassium under reaction conditions on a composite Pt/Rh catalyst has been studied employing photoelectron spectromicroscopy as in situ method during the H 2 + O 2 reaction as discussed by the authors.
11 citations
TL;DR: In this article, the centroids of the Kα and Kβ characteristic lines produced from chromium and manganese compounds were measured and compared with the centroid of X-ray lines generated from the corresponding metals.
11 citations