18O study of the oxidation of reactively sputtered Ti1−xAlxN barrier

2001 ◽  
Vol 16 (9) ◽  
pp. 2591-2599 ◽  
Author(s):  
M. C. Hugon ◽  
F. Varniere ◽  
F. Letendu ◽  
B. Agius ◽  
I. Vickridge ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Nuclear Reaction Analysis ◽  
Oxidation Reactions ◽  
Electrically Conductive ◽  
Al Content ◽  
Perovskite Materials ◽  
Sample Composition ◽  
Before And After ◽  
The Stability ◽  
Concentration Depth Profiles

The preparation of high-permittivity perovskite materials requires high-temperature (550–750 °C) oxidizing environments, providing stringent limitations on the choice of electrode materials. To minimize interdiffusion and oxidation reactions, an electrically conductive diffusion barrier such as Ti1−xAlxN is needed below the electrode material (Pt, IrO2, RuO2…). Ti1−xAlxN films were deposited by multitarget reactive sputtering in a mixture of Ar and N2. The stability of these films has been investigated under typical conditions for crystallization of perovskite dielectrics. Sample composition was characterized using Rutherford backscattering spectroscopy and nuclear reaction analysis. In particular, the concentration depth profiles of both 18O and 27Al were measured before and after RTA treatments via the narrow resonances of 18O(p,α)15N at 151 keV (FWHM = 100 eV) and 27Al(p,γ)28Si at 992 keV (FWHM = 100 eV). The different 18O excitation curves show that the oxidation resistance increases with Al incorporation. The Al excitation curves indicate a uniform Al content for as-deposited TixAl1−xN and reveal Al diffusion to the surface during the oxidation process which indicates the formation of an Al-rich oxide layer at the TixAl1−xN surface, leaving a layer depleted in Al below it.

Narrow Resonance Profiling Study of the Oxidation of Ti1-xALxN Barrier Layer

1999 ◽  
Vol 596 ◽  
Author(s):  
M. C. Hugon ◽  
J. M. Desvignes ◽  
F. Letendu ◽  
B. Agius ◽  
I Vickridge ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Oxidation Reactions ◽  
Electrically Conductive ◽  
Al Content ◽  
Perovskite Materials ◽  
High Annealing ◽  
Before And After ◽  
The Stability ◽  
High Dielectric ◽  
Concentration Depth Profiles

AbstractThe preparation of ferroelectric and high dielectric perovskite materials, which is performed at high temperature (550–750°C) in oxidizing environments, provides strong limitations on the choice of electrode materials which have to be used for integration with semiconductor devices. To minimize interdiffusion and oxidation reactions, a diffusion barrier must be placed between Si substrate and electrode material (Pt, lrO2, RuO2.…). Ti1-xAlxN thin films, deposited by reactive sputtering, are promising materials as electrically conductive layers and robust diffusion barriers. The stability of these films has been investigated at conditions typically used for crystallization of perovskite dielectrics. Films with various Al composition (x=0, 0.1, 0.2 and 0.4) have therefore been annealed by RTA (rapid thermal annealing) in 18O2 at 550–750°C. The concentration depth profiles of both 18O and 27A1 were measured before and after the RTA treatments via the narrow resonances of 18O(p,α)15N at 151 keV (fwhm=100 eV) and 27Al(p,γ)28Si at 992 keV (fwhm=100 eV). Al incorporation in the films reduces oxide growth especially at high annealing temperatures. The Al excitation curves indicate a uniform Al content for as deposited Ti1−xAlxN, and reveal Al diffusion to the surface during oxidation which indicates the formation of an Al rich oxide layer at the Ti1-xAlxN surface.

Parameters for Nitrogen Diffusion in Ni, Ti, and Al Obtained from Implanted Bilayers

1992 ◽  
Vol 279 ◽  
Author(s):  
K. K. Bourdelle ◽  
D. O. Boerma
Keyword(s):  
Nuclear Reaction ◽  
Room Temperature ◽  
Vacuum Annealing ◽  
Nitride Layer ◽  
Nuclear Reaction Analysis ◽  
Nitrogen Diffusion ◽  
Depth Profiles ◽  
Solid Interface ◽  
Before And After ◽  
Concentration Depth Profiles

ABSTRACTNi foils and samples consisting of bilayers of Ni or Fe on Al, Ti or Si were implanted at room temperature with 15N+ ions to fluences of around 1×l017 N/cm2. The concentration depth profiles of 15N were determined with nuclear reaction analysis before and after vacuum annealing. It was found that the penetrability for N atoms of the surface and the solid/solid interface plays an important role in the N redistribution during implantation or annealing. The formation of a nitride layer or nitride clusters in Ni and Fe was deduced. Parameters for N migration determined for the metals under investigation are discussed in terms of models.

Locating Al in the DABCO catalyst before and after Al extraction

1990 ◽  
Vol 48 (4) ◽  
pp. 265-267
Author(s):  
Kathleen B. Reuter
Keyword(s):  
Active Site ◽  
Inverse Relationship ◽  
Transverse Direction ◽  
Reaction Rate ◽  
Acid Phosphate ◽  
Fracture Surfaces ◽  
Al Content ◽  
Before And After ◽  
Relationship Of

The reaction rate and efficiency of piperazine to 1,4-diazabicyclo-octane (DABCO) depends on the Si/Al ratio of the MFI topology catalysts. The Al was shown to be the active site, however, in the Si/Al range of 30-200 the reaction rate increases as the Si/Al ratio increases. The objective of this work was to determine the location and concentration of Al to explain this inverse relationship of Al content with reaction rate.Two silicalite catalysts in the form of 1/16 inch SiO2/Al2O3 bonded extrudates were examined: catalyst A with a Si/Al of 83; and catalyst B, the acid/phosphate Al extracted form of catalyst A, with a Si/Al of 175. Five extrudates from each catalyst were fractured in the transverse direction and particles were obtained from the fracture surfaces near the center of the extrudate diameter. Particles were also obtained from the outside surfaces of five extrudates.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Sorbitol enhances the physicochemical stability of B12 vitamers

2020 ◽  
Vol 90 (5-6) ◽  
pp. 439-447 ◽  
Author(s):  
Andrew Hadinata Lie ◽  
Maria V Chandra-Hioe ◽  
Jayashree Arcot
Keyword(s):  
Ascorbic Acid ◽  
Uv Light ◽  
Heat Exposure ◽  
Water Soluble ◽  
Uv Exposure ◽  
Physicochemical Stability ◽  
Before And After ◽  
The Stability

Abstract. The stability of B12 vitamers is affected by interaction with other water-soluble vitamins, UV light, heat, and pH. This study compared the degradation losses in cyanocobalamin, hydroxocobalamin and methylcobalamin due to the physicochemical exposure before and after the addition of sorbitol. The degradation losses of cyanocobalamin in the presence of increasing concentrations of thiamin and niacin ranged between 6%-13% and added sorbitol significantly prevented the loss of cyanocobalamin (p<0.05). Hydroxocobalamin and methylcobalamin exhibited degradation losses ranging from 24%–26% and 48%–76%, respectively; added sorbitol significantly minimised the loss to 10% and 20%, respectively (p < 0.05). Methylcobalamin was the most susceptible to degradation when co-existing with ascorbic acid, followed by hydroxocobalamin and cyanocobalamin. The presence of ascorbic acid caused the greatest degradation loss in methylcobalamin (70%-76%), which was minimised to 16% with added sorbitol (p < 0.05). Heat exposure (100 °C, 60 minutes) caused a greater loss of cyanocobalamin (38%) than UV exposure (4%). However, degradation losses in hydroxocobalamin and methylcobalamin due to UV and heat exposures were comparable (>30%). At pH 3, methylcobalamin was the most unstable showing 79% degradation loss, which was down to 12% after sorbitol was added (p < 0.05). The losses of cyanocobalamin at pH 3 and pH 9 (~15%) were prevented by adding sorbitol. Addition of sorbitol to hydroxocobalamin at pH 3 and pH 9 reduced the loss by only 6%. The results showed that cyanocobalamin was the most stable, followed by hydroxocobalamin and methylcobalamin. Added sorbitol was sufficient to significantly enhance the stability of cobalamins against degradative agents and conditions.

scholarly journals Investigation of Hydrothermally Stressed Silicone Rubber/Silica Micro and Nanocomposite for the Coating High Voltage Insulation Applications

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3567
Author(s):  
Faiza Faiza ◽  
Abraiz Khattak ◽  
Safi Ullah Butt ◽  
Kashif Imran ◽  
Abasin Ulasyar ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Structural Changes ◽  
Polymer Chains ◽  
Hydrothermal Conditions ◽  
Silica Filler ◽  
Before And After ◽  
Aging Conditions ◽  
The Stability ◽  
Micro Silica ◽  
Applied Stresses

Silicone rubber is a promising insulating material that has been performing well for different insulating and dielectric applications. However, in outdoor applications, environmental stresses cause structural and surface degradations that diminish its insulating properties. This effect of degradation can be reduced with the addition of a suitable filler to the polymer chains. For the investigation of structural changes and hydrophobicity four different systems were fabricated, including neat silicone rubber, a micro composite (with 15% micro-silica filler), and nanocomposites (with 2.5% and 5% nanosilica filler) by subjecting them to various hydrothermal conditions. In general, remarkable results were obtained by the addition of fillers. However, nanocomposites showed the best resistance against the applied stresses. In comparison to neat silicone rubber, the stability of the structure and hydrophobic behavior was better for micro-silica, which was further enhanced in the case of nanocomposites. The inclusion of 5% nanosilica showed the best results before and after applying aging conditions.

scholarly journals Mechanical and Electrical Performance of Flexible Polymer Film Designed for a Textile Electrically-Conductive Path

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2169
Author(s):  
Agnieszka Tabaczyńska ◽  
Anna Dąbrowska ◽  
Marcin Masłowski ◽  
Anna Strąkowska
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Surface Resistance ◽  
Conductive Filler ◽  
Extrusion Process ◽  
Electrical Performance ◽  
Electrically Conductive ◽  
Non Invasive ◽  
Flexible Polymer ◽  
The Stability

Electro-conductive paths that are mechanically resistant and stable during simulated aging cycles are promising, in relation to the non-invasive application in e-textiles in our everyday surroundings. In the paper, an analysis of the influence of electro-conductive filler, as well as ionic liquid on surface resistance is provided. Authors proved that depending on the tested variant, obtained surface resistance may vary from 50 kΩ (when 50 phr of Ag and [bmim][PF6] ionic liquid applied) to 26 GΩ (when 25 phr of Ag and [bmim][PF6] ionic liquid applied). The samples were also evaluated after simulated aging cycles and the stability of electric properties was confirmed. Moreover, it was proved that the addition of ionic liquids reduced the resistance of vulcanizates, while no significant influence of the extrusion process on conductivity was observed.

scholarly journals Rust Conversion Performance of Phosphoric Acid-Gallic Acid in Vinyl Chloride Acrylic Emulsion

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 152
Author(s):  
Xin Wang ◽  
Qingjun Zhu ◽  
Xiangju Liu ◽  
Baorong Hou
Keyword(s):  
Phosphoric Acid ◽  
Gallic Acid ◽  
Vinyl Chloride ◽  
Salt Spray ◽  
Corrosion Current ◽  
Oxidation Reactions ◽  
Acrylic Emulsion ◽  
Conversion Performance ◽  
The Stability ◽  
Iron Complexation

This work studied the application of phosphoric acid-gallic acid in vinyl chloride acrylic emulsion and its rust conversion performance. The increase of phosphoric acid affected the stability of the system, leading to the rapid precipitation of flocculent precipitation. Rust conversion coating (RCC) showed the best synergistic conversion effect when gallic acid (GA) was 0.2 wt.% and phosphoric acid (PA) was 2 wt.%. XRD and FTIR analysis show that the components of adherent rust (AR) are α-FeOOH, γ-FeOOH and Fe3O4. The conversion products are ferric phosphate (FP) and ferric gallate (FG). The RCC can effectively treat the rusted steel (RS) produced by simulated marine atmospheric corrosion. The corrosion current density was reduced by three orders of magnitude, the adhesion reached 2.75 MPa, and the salt spray corrosion resistance was 20 days. The results of Raman, XPS, SEM and EDS show that the ionic dissolution of iron, complexation and further oxidation reactions occur at the interface between the adherent rust and the RCC. After rust conversion treatment, unreacted rust (UR) affects the further improvement of adhesion strength and anti-corrosion performance.

Investigating the stability of electrically conductive membranes

2021 ◽  
Vol 627 ◽  
pp. 119181
Author(s):  
Mohamad Amin Halali ◽  
Melissa Larocque ◽  
Charles-Franҫois de Lannoy
Keyword(s):  
Electrically Conductive ◽  
Conductive Membranes ◽  
The Stability

Regulation of Laijiapu Waterway in Jingjiang Reach

2014 ◽  
Vol 501-504 ◽  
pp. 2001-2006
Author(s):  
Ya Liu ◽  
Li Zheng ◽  
Cheng Tao Huang ◽  
Zhao Biao Huang ◽  
Lin Liu
Keyword(s):  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Three Gorges ◽  
The Yangtze River ◽  
Point Bar ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Before And After ◽  
The Stability ◽  
Channel Bar

After impoundment of the Three Gorges Reservoir, Jingjiang reach, in the middle of the Yangtze River, has gradually shown a series of atypical fluvial features, adversely affecting the maintenance of waterways. Citing the Laijiapu Waterway, a meandering segment in the lower Jingjiang for example, this paper compared the fluvial features of the channel before and after the impoundment, summed up its navigation-obstructing features, and proposed guarding the point bar on the convex bank and channel bar in the widening section as a key to maintaining the stability of the navigation channels.

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