scholarly journals Microstructure and Isothermal Oxidation of Ir–Rh Spark Plug Electrodes

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3226
Author(s):  
Zhao ◽  
Xia ◽  
Xia ◽  
Chen ◽  
Du ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Isothermal Oxidation ◽  
Wire Drawing ◽  
Sem Analysis ◽  
Temperature Oxidation ◽  
X Ray ◽  
Spark Plug ◽  
Corrosion Pits ◽  
Resistance Performance

High-temperature oxidation tests were performed on pure iridium, rhodium, and the iridium alloys, IrRh10, IrRh25, and IrRh40, at 1100 °C in a stable air environment for 60 h. The results of the oxidation were analyzed by X-ray photoelectron spectroscopy (XPS). Microstructural changes of the Ir–Rh alloys were characterized by scanning electron microscopy (SEM). XPS analysis results show that the main oxide of the Ir–Rh alloy in a 1100 °C environment was Rh2O3, and SEM analysis shows that the surfaces of the Ir–Rh alloys after oxidation formed both linear and ellipse-shaped corrosion pits, and had the same direction with the wire-drawing process. The oxidation behavior of Ir–Rh alloys, including the mass change, the reason for the mass loss, and the role of Rh in improving oxidation resistance performance, are discussed.

Transition in high-temperature oxidation kinetics of Pd-modified aluminide coatings: Role of oxygen partial pressure, heating rate, and surface treatment

2000 ◽  
Vol 15 (3) ◽  
pp. 665-675 ◽  
Author(s):  
Daniel Monceau ◽  
Karima Bouhanek ◽  
Raphaëlle Peraldi ◽  
André Malie ◽  
Bernard Pieraggi
Keyword(s):  
Heating Rate ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Alumina Scale ◽  
Isothermal Oxidation ◽  
Temperature Oxidation ◽  
X Ray ◽  
Aluminide Coatings ◽  
Kinetic Transition ◽  
Direct Growth

The isothermal oxidation of Pd-modified Ni aluminide coatings was studied as a function of Po2 and temperature (900–1200 °C). A kinetic transition was observed between 900 and 1000 °C. Grazing incident x-ray diffraction, thermogravimetric analysis, x-ray photoelectron spectroscopy, scanning electron microscopy/energy dispersive spectroscopy, and secondary ion mass spectrometry analyses are consistent with the growth of δ-alumina or α-alumina below or above this transition temperature. Moreover, because Po2 was established before specimen heating, an effect of heating rate was observed and analyzed. More importantly, no kinetic transition was observed for sand-blasted specimens oxidized at low Po2. Thus conditions for the direct growth of an α-alumina scale could be determined from the reported results.

Incorporation and Role of Nitrogen During Oxynitridation of Silicon Studied by Photoelectron Spectroscopy

1999 ◽  
Vol 567 ◽  
Author(s):  
Masayuki Suzuki ◽  
Yoji Saito
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Oxide Films ◽  
Silicon Surfaces ◽  
Gaseous Mixtures ◽  
X Ray ◽  
Initial Stage ◽  
Thermal Stability Of

ABSTRACTWe tried direct oxynitridation of silicon surfaces by remote-plasma-exited nitrogen and oxygen gaseous mixtures at 700°C in a high vacuum. The oxynitrided surfaces were investigated with in-situ X-ray photoelectron spectroscopy. With increase of the oxynitridation time, the surface density of nitrogen gradually increases, but that of oxygen shows nearly saturation behavior after the rapid increase in the initial stage. We also annealed the grown oxynitride and oxide films to investigate the role of the contained nitrogen. The desorption rate of oxygen from the oxynitride films is much less than that from oxide films. We confirmed that nitrogen stabilizes the thermal stability of these oxynitride films.

Deposition of Cobalt Doped Zinc Oxide Thin Film Nano-Composites Via Pulsed Electron Beam Ablation

MRS Advances ◽  
2016 ◽  
Vol 1 (6) ◽  
pp. 433-439 ◽  
Author(s):  
Asghar Ali ◽  
Patrick Morrow ◽  
Redhouane Henda ◽  
Ragnar Fagerberg
Keyword(s):  
Zinc Oxide ◽  
Electron Beam ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Oxide Thin Film ◽  
X Ray ◽  
Pulsed Electron Beam ◽  
Deposited Films

AbstractThis study reports on the preparation of cobalt doped zinc oxide (Co:ZnO) films via pulsed electron beam ablation (PEBA) from a single target containing 20 w% Co on sapphire (0001) and silicon (100) substrates. The films have been deposited at various temperatures (350оC, 400оC, 450оC) and pulse frequencies (2 Hz, 4 Hz), under a background argon (Ar) pressure of about 3 mtorr, and an accelerating voltage of 14 kV. The surface morphology has been examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). According to SEM analysis, the films consist of nano-globules whose size is in the range of 80-178 nm. Energy dispersive x-ray spectroscopy (EDX) reveals that deposition is congruent and the prepared films contain ∼20±5 w% cobalt. It has been found that the nano-globules in the deposited films are cobalt-rich zones containing ∼70 w% Co. From x-ray photoelectron spectroscopy (XPS) analysis, Co 2p3/2 peaks indicate that the deposited films contain CoO (binding energy = 780.5 eV) as well as metallic Co (binding energy = 778.1-778.5 eV). X-ray diffraction (XRD) analysis supports the presence of metallic Co hcp phase (2ϴ = 44.47° and 47.43°) in the films.

High Temperature Oxidation Behavior of SUS310S Austenitic Stainless Steel

2014 ◽  
Vol 941-944 ◽  
pp. 212-215
Author(s):  
Tao Zheng ◽  
Jing Tao Han
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Behavior ◽  
Layer Structure ◽  
Energy Dispersive Spectrometer ◽  
Austenitic Stainless Steels ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
High Oxidation Resistance ◽  
Ray Diffusion

The oxidation behavior of SUS310S austenitic stainless steels was studied in isothermal conditions at different temperatures between 800oC and 1100oC for 96h in air. The oxidation kinetics was analyzed, the surface and cross-section of the oxide scale grown by oxidation were characterized by using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffusion (XRD) and X-ray photoelectron spectroscopy (XPS). The SUS310S steel has high oxidation resistance at 800oC and with the increase of the temperature, the parabolic rate constants is constantly increasing. Examination of the morphology and composition of oxide layers reveals a double-layer structure, The inner layer is mainly chromium oxide (Cr2O3) and is covered by an uneven thinness outer layer of manganese-chromium or iron-chromium spinel oxide.

scholarly journals Photocatalytic activity of graphene oxide–TiO 2 thin films sensitized by natural dyes extracted from Bactris guineensis

2019 ◽  
Vol 6 (3) ◽  
pp. 181824 ◽  
Author(s):  
William Vallejo ◽  
Angie Rueda ◽  
Carlos Díaz-Uribe ◽  
Carlos Grande ◽  
Patricia Quintana
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Photocatalytic Degradation ◽  
Photoelectron Spectroscopy ◽  
Chemical Characterization ◽  
Sem Analysis ◽  
Visible Range ◽  
X Ray ◽  
Natural Sensitizer

This study synthesized and characterized composites of graphene oxide and TiO 2 (GO–TiO 2 ). GO–TiO 2 thin films were deposited using the doctor blade technique. Subsequently, the thin films were sensitized with a natural dye extracted from a Colombian source ( Bactris guineensis ). Thermogravimetric analysis, X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance measurements were used for physico-chemical characterization. All the samples were polycrystalline in nature, and the diffraction signals corresponded to the TiO 2 anatase crystalline phase. Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) verified the synthesis of composite thin films, and the SEM analysis confirmed the TiO 2 films morphological modification after the process of GO incorporation and sensitization. XPS results suggested a possibility of appearance of titanium (III) through the formation of oxygen vacancies (O v ). Furthermore, the optical results indicated that the presence of the natural sensitizer and GO improved the optical properties of TiO 2 in the visible range. Finally, the photocatalytic degradation of methylene blue was studied under visible irradiation in aqueous solution, and pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation. These results indicated that the presence of GO has an important synergistic effect in conjunction with the natural sensitizer, reaching a photocatalytic yield of 33%.

scholarly journals Defective TiO2 Core-Shell Magnetic Photocatalyst Modified with Plasmonic Nanoparticles for Visible Light-Induced Photocatalytic Activity

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 672 ◽  
Author(s):  
Zuzanna Bielan ◽  
Agnieszka Sulowska ◽  
Szymon Dudziak ◽  
Katarzyna Siuzdak ◽  
Jacek Ryl ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Phenol Degradation ◽  
Magnetic Core ◽  
Magnetic Photocatalyst ◽  
X Ray ◽  
Transmission Electron ◽  
First Time

In the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanoparticles with well-defined titanium vacancies, was successfully obtained. Introducing platinum and copper nanoparticles (NPs) as surface modifiers of defective d-TiO2 significantly increased the photocatalytic activity in both UV-Vis and Vis light ranges. Moreover, metal NPs deposition on the magnetic core allowed for the effective separation and reuse of the nanometer-sized photocatalyst from the suspension after the treatment process. The obtained Fe3O4@SiO2/d-TiO2-Pt/Cu photocatalysts were characterized by X-ray diffractometry (XRD) and specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Further, the mechanism of phenol degradation and the role of four oxidative species (h+, e−, •OH, and •O2−) in the studied photocatalytic process were investigated.

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