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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, the effects of reflector bias voltage on the physical and chemical properties of nanocrystalline silicon deposited by reactive particle beam assisted chemical vapor deposition were systematically studied using various reflectors bias voltages.
Abstract: In the present study, the effects of reflector bias voltage on the physical and chemical properties of nanocrystalline silicon deposited by reactive particle beam assisted chemical vapor deposition were systematically studied using various reflector bias voltages. During deposition, the substrate temperature was kept at room temperature. Nanocrystalline Si embedded in an amorphous matrix structure was analyzed by X-ray diffraction and Raman spectroscopy. Films that were deposited under high reflector voltage formed large grains due to largely accumulated internal energy. Using X-ray photoelectron spectroscopy, the chemical state of nanocrystalline silicon was revealed to have only metallic Si bonds. Further, an increase in reflector voltage induced a roughened surface morphology, an increased dark conductivity, and a decreased optical band gap in Si films.
4 citations
TL;DR: In this paper, the authors used X-ray diffraction pattern to identify chemical composition, chemical state and binding energy of ionic species in (1-x)BNKT-xLN ceramics.
Abstract: Lead-free piezoelectric ceramics with formula of (1-x)Bi0.5(Na0.80K0.20)0.5TiO3-xLiNbO3 or (1-x)BNKT-xLN (when x = 0, 0.005, 0.010, 0.015 and 0.020 mol fraction) were produced by a solid-state mixed oxide method. The ceramics with density ranging 5.38 - 5.68 g/cm3 were obtained by sintering at 1100°C. X-ray diffraction pattern showed that (1-x)BNKT-xLN ceramics exhibited pure perovskite structure. X-ray photoelectron spectroscopy analysis was used to identify of chemical composition, chemical state and binding energy of ionic species in the ceramics. Dielectric, ferroelectric and piezoelectric properties of all ceramics were investigated and found to be optimized at the composition of x = 0.005.
4 citations
TL;DR: X-ray photoelectron spectroscopy and X-ray absorption near edge structure studies showed that the chemical state of the W nanoparticles simultaneously exhibits metallic W(∼0) and carbide W(δ+) character, which suggests that the combination of early-transition-metal atoms and carbon-based supports would afford modulatable electronic systems though the electronic interactions.
Abstract: Carbothermal hydrogen reduction (CHR) is a unique dry chemical process used to fabricate metals and carbides on carbon supports. In this study, a stepwise CHR of WCl6 on a graphite support is demonstrated for the first time. Powder X-ray diffraction studies revealed that, at 773 K, metallic tungsten nanoparticles are produced, whereas, at 1073 K, the metastable W2C phase is generated rather than the thermodynamically stable WC phase. X-ray photoelectron spectroscopy and X-ray absorption near edge structure studies showed that the chemical state of the W nanoparticles simultaneously exhibits metallic W(∼0) and carbide W(δ+) character. The obtained results suggest that, although electronic interactions exist between the metallic W atoms and the graphite support, the body-centered cubic structure of the metallic tungsten is maintained, confirmed by the extended X-ray absorption fine structure. In addition, high-resolution scanning transmission electron microscopy observations revealed that the W nanoparticles exhibit a thin flattened shape on the support. These results support the notion that the mechanism for the formation of the W nanoparticles during the CHR is influenced by the electronic interactions between the W nanoparticles and the graphite support. Our work thus suggests that the combination of early-transition-metal atoms and carbon-based supports would afford modulatable electronic systems though the electronic interactions.
4 citations
TL;DR: In this paper, photo and electrochemical doping of obliquely deposited Ge-chalcogenide films have been studied by AES/XPS techniques and the effect of electrochemical adsorption and photodoping on the optical transmittance is presented.
Abstract: Photo and electrochemical doping of obliquely deposited Ge-chalcogenide films have been studied by AES/XPS techniques. The effect of electrochemical adsorption and photodoping on the optical transmittance is presented. The atomic concentration depth profiles of Ag-sensitized amorphous Ge and Ge 0.25 Se 0.75 films have been established. The chemical state of Ag and the associated chemical changes in the chalcogenide brought about by photo and electrochemical doping processes have been identified. Some details of the built-in columnar structure and stresses in obliquely deposited films have been revealed by the present study.
4 citations
TL;DR: Amorphous carbon nitride films were prepared at various substrate bias voltage V b using magnetic filtered plasma stream as mentioned in this paper, which was formed by sputtering a high-purity graphite target in nitrogen atmosphere.
4 citations