Surface Composition Analysis of HF Vapor Cleaned Silicon by X Ray Photoelectron Spectroscopy

1990 ◽  
Author(s):  
Anne ERMOLIEFF ◽  
F. MARTIN ◽  
A. AMOUROUX ◽  
S. MARTHON ◽  
J. F. M WESTENDORP
1991 ◽  
Vol 48-49 ◽  
pp. 178-184 ◽  
Author(s):  
A. Ermolieff ◽  
F. Martin ◽  
A. Amouroux ◽  
S. Marthon ◽  
J.F.M. Westendorp

2020 ◽  
Vol 67 (6) ◽  
pp. 529-536
Author(s):  
Shima Nakisa ◽  
Naghi Parvini Ahmadi ◽  
Javad Moghaddam ◽  
Habib Ashassi-Sorkhabi

Purpose The composition and corrosion behaviors of recycled and virgin Pb anode were investigated in industrial zinc electrowinning solution with different methods. The purpose of this study is the illustration of good anticorrosion activity of virgin Pb anodes compared to recycled one in industrial operation, while the compositions of both of them are the same which obtained from quantmetry method. Design/methodology/approach Its corrosion properties and electrocatalytic activity toward oxygen evolution reaction were appraised using potentiodynamic polarization, electrochemical impedance spectroscopy, galvanostatic polarization and ionic equilibrium methods. In addition, composition of anodes investigated with X-ray photoelectron spectroscopy (XPS) method. The surface composition of samples was studied via X-ray diffractogram (XRD). Findings The results indicate that the anodes display different anodic behaviors during the galvanostatic polarization. Virgin Pb anode shows a “potential reduction” about 320 mV lower than recycled Pb anode after 6 h of polarization; also, the stable potential after 72 h for virgin Pb anode is 100 mV lower than recycled Pb anode. Also, The XPS results show a trace amount of Cl in recycled anodes which cause the more corrosion activity. XRD results indicate that virgin Pb anodes have been covered by more oxides than recycled anodes after 72 h of electrowinning. Originality/value The treatment of corrosion behavior by virginity has not been detected by any researchers yet. Therefore, it is imperative to study the corrosion behavior and exact composition analysis of virgin and recycled Pb anodes to comprehension of them. This paper fulfills this need.


2021 ◽  
Author(s):  
Ganesh Kumar K ◽  
Balaji Bhargav ◽  
K Aravinth ◽  
Balaji C

Abstract Ce3+/ Li+ activated barium aluminate phosphor (BAO) was synthesized by conventional solid-state reaction method. The crystal structure of the synthesized phosphor was analyzed by X-ray diffraction (XRD) and Raman spectroscopy analysis. FT-IR spectrum results revealed the characteristic vibration bands present in the synthesized phosphor. Surface composition analysis of the prepared samples was examined using X-ray photoelectron spectroscopy (XPS). PL emission band observed at 589 nm was assigned to 5D excited level corresponding to 2F5/2 transition in yellow region under the excitation wavelength of 320 nm. Yellow light emission was confirmed by the Commission Internationale de L’Eclairage (CIE) chromatic coordinate graph. The color purity of BAO: 0.5Ce3+, BAO: 0.5Ce3+, 0.1Li+ was found to be 78.4 %, 81.3 % whereas the measured lifetime was 4.333, 4.738 ns respectively.


1991 ◽  
Vol 6 (2) ◽  
pp. 98-102 ◽  
Author(s):  
A Ermolieff ◽  
F Martin ◽  
A Amouroux ◽  
S Marthon ◽  
J F M Westendorp

2020 ◽  
Author(s):  
Jennifer A. Rudd ◽  
Ewa Kazimierska ◽  
Louise B. Hamdy ◽  
Odin Bain ◽  
Sunyhik Ahn ◽  
...  

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher value products. Herein, we describe the use of porous copper electrodes to catalyze the reduction of carbon dioxide into higher value products such as ethylene, ethanol and, notably, propanol. For <i>n</i>-propanol production, faradaic efficiencies reach 4.93% at -0.83 V <i>vs</i> RHE, with a geometric partial current density of -1.85 mA/cm<sup>2</sup>. We have documented the performance of the catalyst in both pristine and urea-modified foams pre- and post-electrolysis. Before electrolysis, the copper electrode consisted of a mixture of cuboctahedra and dendrites. After 35-minute electrolysis, the cuboctahedra and dendrites have undergone structural rearrangement. Changes in the interaction of urea with the catalyst surface have also been observed. These transformations were characterized <i>ex-situ</i> using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We found that alterations in the morphology, crystallinity, and surface composition of the catalyst led to the deactivation of the copper foams.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.


2018 ◽  
Vol 122 (10) ◽  
pp. 2695-2702 ◽  
Author(s):  
E. Antonsson ◽  
C. Raschpichler ◽  
B. Langer ◽  
D. Marchenko ◽  
E. Rühl

2006 ◽  
Vol 600 (18) ◽  
pp. 3749-3752 ◽  
Author(s):  
C. Biswas ◽  
S. Banik ◽  
A.K. Shukla ◽  
R.S. Dhaka ◽  
V. Ganesan ◽  
...  

2014 ◽  
Vol 16 (39) ◽  
pp. 21486-21495 ◽  
Author(s):  
Josephina Werner ◽  
Jan Julin ◽  
Maryam Dalirian ◽  
Nønne L. Prisle ◽  
Gunnar Öhrwall ◽  
...  

The water–vapor interface of aqueous solutions of succinic acid, where pH values and bulk concentrations were varied, has been studied using surface sensitive X-ray photoelectron spectroscopy (XPS) and molecular dynamics (MD) simulations.


Author(s):  
Changqing Liu ◽  
David A. Hutt ◽  
Dezhi Li ◽  
Paul P. Conway

This paper aims to gain an insight into the correlation between the microstructure and surface composition of electroless Ni-P and its behaviour during soldering with Pb free alloys including Sn-3.8Ag-0.7Cu, Sn-3.5Ag and Sn-0.7Cu. Ni-P coatings with different P contents were produced through an industrial process on copper metal substrates. The surface morphology of these coatings was observed by Scanning Electron Microscopy (SEM) and the bulk composition was analyzed by means of Energy Dispersive X-ray analysis (EDX). The mechanical properties of the coatings were evaluated by nano-indentation testing under different maximum loads. However, to understand the behaviour of P in Ni-P coatings and deterioration of the coating surfaces during exposure to air, the surfaces of the coatings were also characterised by X-ray Photoelectron Spectroscopy (XPS) for storage at different temperatures. The dependence of the solderability of Ni-P coatings on the storage time and temperature was investigated by wetting balance testing, using an inactive or active flux with or without an inert N2 atmosphere. Finally, the solderability of Ni-P coatings to Pb free solders is correlated with their composition and microstructure (e.g. surface characteristics).


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