Reactions at the interface between multi-component glasses and metallic lithium films

1989 ◽  
Vol 4 (4) ◽  
pp. 978-989 ◽  
Author(s):  
K. R. Zavadil ◽  
N. R. Armstrong ◽  
C. H. F. Peden
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Surface Region ◽  
Alloy Formation ◽  
Sodium Potassium ◽  
Near Surface ◽  
Network Modifier ◽  
X Ray ◽  
Metallic Lithium

The reactions of vacuum deposited thin films of lithium with various complex glasses have been explored using x-ray photoelectron spectroscopy (XPS). In contrast to lithium reactions with simple glasses such as silica or boron oxides, the reactions are predominantly those of the network modifiers such as sodium, potassium, and magnesium. XPS and x-ray induced Auger lineshapes indicate the migration of the network modifier to the near surface region followed by its reduction. In the case of magnesium, there is evidence for stable alloy formation with unreacted lithium following these migration and reduction steps.

Revealing the mechanism of the early stages of Ni–W RABiTS oxidation

2010 ◽  
Vol 25 (12) ◽  
pp. 2362-2370 ◽  
Author(s):  
Andrey V. Blednov ◽  
Oleg Yu. Gorbenko ◽  
Dmitriy P. Rodionov ◽  
Andrey R. Kaul
Keyword(s):  
Internal Oxidation ◽  
Photoelectron Spectroscopy ◽  
Oxidation Mechanism ◽  
Surface Oxidation ◽  
Surface Region ◽  
Near Surface ◽  
Precise Position ◽  
X Ray ◽  
Early Stages ◽  
Phase And Chemical Composition

The early stages of surface oxidation of biaxially textured Ni–W tapes were studied using thermodynamic calculations along with experimental tape oxidation at low P(O2). Tape phase and chemical composition, surface morphology, and roughness were examined using x-ray diffraction (XRD), energy-dispersive x-ray analysis (EDX), secondary ion mass spectroscopy (SIMS), x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). For a Ni0.95W0.05 alloy tape, the precise position of the tape oxidation line in P(O2)–T coordinates was established. This line includes a break at T ≈ 650 °C that originates from the change of the W oxidation mechanism from internal oxidation to oxidation on a free surface accompanied by segregation of the alloy components in the tape near-surface region. The surface roughness of a polished tape increased drastically during internal oxidation of W; further tape oxidation did not affect the integral roughness parameters, but introduced numerous small (˜;100 nm) features on the tape surface comprising NiO precipitates.

scholarly journals Microstructure and Mechanical Properties of Ti + N Ion Implanted Cronidur30 Steel

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 427 ◽  
Author(s):  
Jie Jin ◽  
Wei Wang ◽  
Xinchun Chen
Keyword(s):  
Mechanical Properties ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
Structural Modification ◽  
Surface Region ◽  
Grazing Incidence ◽  
Bearing Steel ◽  
Near Surface ◽  
X Ray ◽  
Ion Implanted

In this study, Ti + N ion implantation was used as a surface modification method for surface hardening and friction-reducing properties of Cronidur30 bearing steel. The structural modification and newly-formed ceramic phases induced by the ion implantation processes were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and grazing incidence X-ray diffraction (GIXRD). The mechanical properties of the samples were tested by nanoindentation and friction experiments. The surface nanohardness was also improved significantly, changing from ~10.5 GPa (pristine substrate) to ~14.2 GPa (Ti + N implanted sample). The friction coefficient of Ti + N ion implanted samples was greatly reduced before failure, which is less than one third of pristine samples. Furthermore, the TEM analyses confirmed a trilamellar structure at the near-surface region, in which amorphous/ceramic nanocrystalline phases were embedded into the implanted layers. The combined structural modification and hardening ceramic phases played a crucial role in improving surface properties, and the variations in these two factors determined the differences in the mechanical properties of the samples.

ZrC Thin Films Grown by Pulsed Laser Deposition

2003 ◽  
Vol 780 ◽  
Author(s):  
V. Craciun ◽  
D. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Surface Region ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Crystalline Films

AbstractZrC thin films were grown on Si substrates by the pulsed laser deposition (PLD) technique. X- ray photoelectron spectroscopy, x-ray diffraction and reflectivity, variable angle spectroscopic ellipsometry, and four point probe measurements were used to investigate the composition, density, thickness, surface morphology, optical and electrical properties of the grown structures. It has been found that crystalline films could be grown only by using fluences above 6 J/cm2 and substrate temperatures in excess of 500 °C. For a fluence of 10 J/cm2 and a substrate temperature of 700 °C, highly (100)-textured ZrC films exhibiting a cubic structure (a=0.469 nm) and a density of 6.7 g/cm3 were deposited. The use of a low-pressure atmosphere of C2H2 had a beneficial effect on crystallinity and stoichiometry of the films. All films contained high levels of oxygen contamination, especially in the surface region, because of the rather reactive nature of Zr atoms.

An Examination of Kernite (Na2B4O6(OH)2·3H2O) Using X-Ray and Electron Spectroscopies: Quantitative Microanalysis of a Hydrated Low-Z Mineral

2011 ◽  
Vol 17 (5) ◽  
pp. 718-727 ◽  
Author(s):  
Douglas C. Meier ◽  
Jeffrey M. Davis ◽  
Edward P. Vicenzi
Keyword(s):  
Electron Beam ◽  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Stoichiometric Composition ◽  
Surface Region ◽  
Variable Pressure ◽  
Sampling Depth ◽  
Electrical Insulator ◽  
Near Surface ◽  
X Ray

AbstractMineral borates, the primary industrial source of boron, are found in a large variety of compositions. One such source, kernite (Na2B4O6(OH)2·3H2O), offers an array of challenges for traditional electron-probe microanalysis (EPMA)—it is hygroscopic, an electrical insulator, composed entirely of light elements, and sensitive to both low pressures and the electron beam. However, the approximate stoichiometric composition of kernite can be analyzed with careful preparation, proper selection of reference materials, and attention to the details of quantification procedures, including correction for the time dependency of the sodium X-ray signal. Moreover, a reasonable estimation of the mineral's water content can also be made by comparing the measured oxygen to the calculated stoichiometric oxygen content. X-ray diffraction, variable-pressure electron imaging, and visual inspection elucidate the structural consequences of high vacuum treatment of kernite, while Auger electron spectroscopy and X-ray photoelectron spectroscopy confirm electron beam-driven migration of sodium and oxygen out of the near-surface region (sampling depth ≈ 2 nm). These surface effects are insufficiently large to significantly affect the EPMA results (sampling depth ≈ 400 nm at 5 keV).

Polyhedral Oligomeric Silsesquioxane/PDMS Hybrid Coating Protecting Polyimide from Atomic Oxygen Erosion

2011 ◽  
Vol 189-193 ◽  
pp. 336-339 ◽  
Author(s):  
Shu Wang Duo ◽  
Mi Mi Song ◽  
Ting Zhi Li ◽  
Ying Luo ◽  
Mei Shuan Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hybrid Film ◽  
Surface Region ◽  
Polyimide Film ◽  
Hybrid Films ◽  
Near Surface ◽  
X Ray ◽  
Oligomeric Silsesquioxane ◽  
Atomic Oxygen Erosion ◽  
Inorganic Organic Polymers

Hybrid inorganic/organic polymers have been prepared by copolymerizing a silanol terminated polydimethylsiloxane (PDMS) with an Octa(aminophenyl) -silsesquioxane (POSS). The AO resistance of these POSS/PDMS hybrid films was tested in the ground-based AO simulation facility. Exposed and unexposed surfaces have been characterized by X-ray photoelectron spectroscopy. The XPS data indicate that the carbon content of the near-surface region is decreased from 65.3 to 18.9 at% after AO exposure. The oxygen and silicon concentrations in the near-surface region increase after AO exposure. The data reveal the formation of a passive inorganic SiO2 layer on the POSS/PDMS hybrid films during the AO exposure, which serves as a protective barrier preventing further degradation of the underlying polymer with increased exposure to the AO flux. The erosion yield of the POSS/PDMS (20 wt%) hybrid film was 1.7×10-26 cm3/atom, decreased by two orders of magnitude compared with the value of 3.0×10-24 cm3/atom of the polyimide film.

Surface chemical states of barium titanate: Influence of sample processing

1995 ◽  
Vol 10 (6) ◽  
pp. 1502-1507 ◽  
Author(s):  
Sharmila M. Mukhopadhyay ◽  
Tim C.S. Chen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Reduction ◽  
Surface Region ◽  
Annealing Atmosphere ◽  
Near Surface ◽  
X Ray ◽  
Reducing Atmosphere ◽  
Special Surface ◽  
Chemical States ◽  
Photoelectron Peak

The composition and chemistry of the near-surface region of BaTiO3 have been studied using x-ray photoelectron spectroscopy (XPS). It is found that the Ba3d photoclectron peak shows two chemical states, one of which is attributed to the bulk perovskite and the other to a special surface state unrelated to contamination. The bulk component is reduced and the surface component increases when the material is annealed at high temperatures (either in reducing or oxidizing atmosphere). Both the components are unaltered if the sample is exposed to air, solvents, or water: processes that lead to adsorption of impurities. The surface peak, therefore, attributed to a relaxation related and not contamination-related state, has been compared with those in other Ba-containing oxides. The oxygen photoelectron peak consists of a normal perovskite peak typical of most titanates and a higher energy component clearly related to surface contamination. Annealing in reducing atmosphere results in drastically different optical and electrical properties, and in chemical reduction of some Ti4+ ions to Ti3+. The overall stoichiometry, however, does not change with annealing atmosphere. These results have been discussed in light of our current understanding of this and other related oxides.

Fabrication of CaWO4:Eu3+ Thin Films via Electrochemical Methods Assisted by a Novel Post Treatment

2011 ◽  
Vol 194-196 ◽  
pp. 2458-2461 ◽  
Author(s):  
Lian Ping Chen ◽  
Yuan Hong Gao ◽  
Jian Xiong Yuan ◽  
Qing Hua Zhang ◽  
Yan Hong Yin ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Electrochemical Techniques ◽  
Surface Region ◽  
Luminescent Properties ◽  
Emission Peak ◽  
X Ray Diffraction ◽  
Near Surface ◽  
X Ray ◽  
Rare Earth Doped

It is hardly possible to obtain rare earth doped CaWO4 thin films directly through electrochemical techniques. A novel post processing has been proposed to synthesize CaWO4:Eu3+ thin films at room temperature. X-ray diffraction, X-ray photoelectron spectrometry, spectrophotometer were used to characterize their phase, composition and luminescent properties. Results reveal that Eu3+-doped CaWO4 films have a tetragonal phase; the content of Eu in the near surface region is much higher than that of the bulk; under the excitation of 310 nm, a sharp emission peak at 616 nm has been observed for Ca0.9WO4:Eu0.13+ thin films.

Layered structure of the near-surface region of oxidized chalcopyrite (CuFeS2): hard X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and DFT+U studies

2017 ◽  
Vol 19 (4) ◽  
pp. 2749-2759 ◽  
Author(s):  
Yuri Mikhlin ◽  
Vladimir Nasluzov ◽  
Alexander Romanchenko ◽  
Yevgeny Tomashevich ◽  
Alexey Shor ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Layered Structure ◽  
Photoelectron Spectroscopy ◽  
Metal Sulfide ◽  
Surface Region ◽  
Near Surface ◽  
X Ray ◽  
X Ray Absorption

Metal-depleted layers with different S species are found, and mechanisms for their formation and metal sulfide ‘passivation’ are proposed.

Effect of Atomic Oxygen Exposure on Polyhedral Oligomeric Silsesquioxane/Polyimide Hybrid Materials in Low Earth Orbit Environment

2011 ◽  
Vol 492 ◽  
pp. 521-524 ◽  
Author(s):  
Shu Wang Duo ◽  
Mi Mi Song ◽  
Ting Zhi Liu ◽  
Chang Yuan Hu ◽  
Mei Shuan Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Atomic Oxygen ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Surface Region ◽  
Low Earth Orbit ◽  
Hybrid Films ◽  
Sem Images ◽  
Near Surface ◽  
X Ray ◽  
Oligomeric Silsesquioxane

A novel polyimide (PI) hybrid nanocomposite containing polyhedral oligomeric silsesquioxane (POSS) had been prepared by copolymerization of octa(aminophenyl)silsesquioxane (OAP-POSS), 4,4’ -oxydianiline (ODA), and pyromellitic dianhydride (PMDA). The AO resistance of these POSS/PI hybrid films was tested in the ground-based AO simulation facility. Exposed and unexposed surfaces have been characterized by X-ray photoelectron spectroscopy and FTIR. The XPS data indicate that the carbon content of the near-surface region is decreased from 63.6 to 19.3 at% after AO exposure. The oxygen and silicon concentrations in the near-surface region increase after AO exposure. The data reveal the formation of a passive inorganic SiO2 layer on the POSS/PI hybrid films during the AO exposure, which serves as a protective barrier preventing further degradation of the underlying polymer with increased exposure to the AO flux. SEM images showed that the surface of the 10 wt% POSS/PI became much less rough than that of the pristine polyimide. The AO resistance of the POSS/PI hybrid films is up to several tenfold than that of the pristine polyimide.

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