Search results for " interfaces"
showing 10 items of 1158 documents
Evidence of hexagonal WO3 structure stabilization on mica substrate
2009
International audience; WO3 nanorods are grown by a simple vapor deposition method on a mica substrate and characterized by Selected Area Electron Diffraction and Energy Dispersive X-rays Spectroscopy. Experimental results show the clear evidence of an unexpected WO3 hexagonal structure as well as an epitaxial growth on the mica substrate. Besides, potassium is evidenced inside the nanorods. It is thus deduced that a metastable WO3 hexagonal phase is stabilized by epitaxy through a tungsten bronze interlayer having same hexagonal structure.
Solid–Solid Interfaces in Protonic Ceramic Devices: A Critical Review
2020
The literature concerning protonic ceramic devices is critically reviewed focusing the reader's attention on the structure, composition, and phenomena taking place at solid-solid interfaces. These interfaces play a crucial role in the overall device performance, and the relevance of understanding the phenomena taking place at the interfaces for the further improvement of electrochemical protonic ceramic devices is therefore stressed. The grain boundaries and heterostructures in electrolytic membranes, the electrode-electrolyte contacts, and the interfaces within composite anode and cathode materials are all considered, with specific concern to advanced techniques of characterization and to …
Metal-organic chemical vapor deposition of Cr2O3 and Nd2O3 coatings. Oxide growth kinetics and characterization
2000
Thin oxide films of Cr2O3 and Nd2O3 were prepared, using Metal-Organic Chemical Vapor Deposition (MOCVD) technique, to protect stainless steels against corrosion at high temperature. The conditions of precursor volatilization were studied by thermogravimetry. Deposited film growth kinetics depended on the deposition parameters, particularly substrate temperature, gas flow rate and location of substrate in the coating reactor. The influence of the deposition parameters on the deposition rate and the uniformity of the films is discussed. The oxide films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force mi…
A combined computational and experimental study on the mild steel corrosion inhibition in hydrochloric acid by new multifunctional phosphonic acid co…
2020
Two triazole derivatives with phosphonic acid as pendent group, namely [3-(4-phenyl-[1–3]triazol-1-yl)-propyl]-phosphonicaciddiethylester (PTP) and [3-[4-(4-dimethylamino-phenyl)-[1–3]triazol-1-yl]-propyl]-phosphonic acid diethylester (DMPTP) were synthesized and fully characterized using NMR spectroscopy, Mass spectrometry, Infra-Red (FT-IR) spectroscopy and elemental analysis. The synthesized multifunctional heterocycles were investigated to inhibit the corrosion of mild steel in acidic solution HCl (1 M) by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and weight loss measurements. The results of the different corrosion measurement techniques are in goo…
In situ diagnostics and control of laser-induced removal of iron oxide layers
2002
The mechanism of laser-induced removal of thermally grown iron oxide layers on pure iron has been investigated by means of in situ reflectivity measurements. The experiments were carried out by irradiating the sample with λ=584 nm, τ=6 ns (FWHM) laser pulses in a buffer borate solution after a cathodic polarisation of - 1.5 V/SCE had been applied during 40 min. The removal efficiency has been studied as a function of the number of laser pulses, for several fluence values and for a few time delays after switching off the cathodic polarisation. The results demonstrate that reflectivity measurements are a suitable non-invasive in situ diagnostics tool for the assessment of the efficiency of ox…
Correlated effects of fluorine and hydrogen in fluorinated tin oxide (FTO) transparent electrodes deposited by sputtering at room temperature
2021
The optical and electrical properties of fluorinated tin oxide (FTO) films deposited at room temperature by sputtering have been investigated varying the fluorine content and the hydrogen atmosphere. The complex behavior of the obtained films is disclosed using a wide set of characterization techniques that reveals the combined effects of these two parameters on the generated defects. These defects control the electrical transport (carrier density, mobility and conductivity), the optical properties (band gap and defects-related absorption and photoluminescence) and finally promote the amorphization of the samples. H2 in the sputtering gas does not modify the H content in the films but induc…
DFT studies of OH-functionalized open-ended zigzag, armchair, and chiral single wall carbon nanotubes
2011
The functionalization of single-wall carbon nanotubes (SWCNTs) by attaching various molecules or molecular groups to the exterior walls or tips has attracted much attention, because it offers a possible way to modify their electronic, chemical, optical and mechanical properties. In this contribution the results of DFT studies of pristine and OH-modified open-ended zigzag (9,0), armchair (5,5) and chiral (8,2) nanotubes are reported. The calculations have been performed for partially and fully functionalized at one end model SWCNTs with dangling bonds saturated with hydrogen atoms and a nonadditive dependence of attachment energy on the number of substituents was observed.
The commensurate-incommensurate transition of hydrogen monolayers physisorbed on graphite
1987
We present a neutron diffraction study of the commensurate-incommensurate (C-IC) transition of hydrogen monolayers physisorbed on the basal planes of exfoliated graphite. It is shown that the solid intermediate phase detected by specific-heat measurements can be described in terms of a striped domain-wall phase with superheavy walls. Comparison with simple models with fixed domain sizes is made. The results are in agreement with recent LEED experiments of Cui and Fain and provide an experimental realization of C-IC transition theories.
Pulsed laser cleaning of oxidized metallic surfaces in electrochemically controlled liquid confinement
1997
Pulsed laser cleaning of oxidized metallic surfaces is studied. To our knowledge, for the first time, it has been demonstrated that the application of pulsed laser irradiation in a liquid confinement at controlled electrochemical potential enhances the oxide film removal from metal surfaces. Systematic studies on simulated corrosion product films using optical reflectance profile, energy dispersive X-ray spectroscopy, and piezoelectric transducer measurements, have revealed that efficient oxide film removal by laser irradiation is achieved if a basic electrolyte solution is used and a cathodic potential is imposed. The advantages of this novel technique against laser irradiation in air are …
Properties of AlN grown by plasma enhanced atomic layer deposition
2011
Abstract The influence of growth parameters on the properties of AlN films fabricated by plasma-enhanced atomic layer deposition using trimethylaluminum and ammonia precursors was investigated. The atomic concentrations, refractive index, mass density, crystallinity and surface roughness were studied from the films grown in the temperature range of 100–300 °C with plasma discharge times between 2.5 and 30 s. The AlN films were shown to be hydrogen rich having H concentrations in the range of 13–27 at.% with inverse dependence on the growth temperature. The carbon and oxygen concentrations in the films were less than 2.6% and 0.2%, respectively. The refractive index and mass density of the f…