X-ray Photoelectron Spectroscopy (XPS) Investigation of the Surface Film on Magnesium Powders

2012 ◽  
Vol 66 (5) ◽  
pp. 510-518 ◽  
Author(s):  
Paul J. Burke ◽  
Zeynel Bayindir ◽  
Georges J. Kipouros
Keyword(s):  
Surface Layer ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Surface Film ◽  
Ion Beam ◽  
Pure Magnesium ◽  
Atmospheric Conditions ◽  
Magnesium Powder ◽  
X Ray ◽  
Aerospace Applications

Magnesium (Mg) and its alloys are attractive for use in automotive and aerospace applications because of their low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. Powder metallurgy may be a suitable solution for forming near-net-shape parts. However, sintering pure magnesium presents difficulties due to surface film that forms on the magnesium powder particles. The present work investigates the composition of the surface film that forms on the surface of pure magnesium powders exposed to atmospheric conditions and on pure magnesium powders after compaction under uniaxial pressing at a pressure of 500 MPa and sintering under argon at 600 °C for 40 minutes. Initially, focused ion beam microscopy was utilized to determine the thickness of the surface layer of the magnesium powder and found it to be ∼10 nm. The X-ray photoelectron analysis of the green magnesium sample prior to sintering confirmed the presence of MgO, MgCO3·3H2O, and Mg(OH)2 in the surface layer of the powder with a core of pure magnesium. The outer portion of the surface layer was found to contain MgCO3·3H2O and Mg(OH)2, while the inner portion of the layer is primarily MgO. After sintering, the MgCO3·3H2O was found to be almost completely absent, and the amount of Mg(OH)2 was also decreased significantly. This is postulated to occur by decomposition of the compounds to MgO and gases during the high temperature of sintering. An increase in the MgO content after sintering supports this theory.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

The Nc State Analytical Instrumentation Facility

1999 ◽  
Vol 5 (S2) ◽  
pp. 10-11
Author(s):  
J.R. Phillips ◽  
D.P. Griffis ◽  
P.E. Russell
Keyword(s):  
Surface Science ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Non Profit ◽  
X Ray ◽  
Industrial Organizations ◽  
Extensive Collection ◽  
Analytical Instrumentation ◽  
Analytical Services

The Analytical Instrumentation Facility (AIF) is a laboratory composed of scientists and engineers specializing in the development and application of advanced techniques for materials characterization (http://spm.aif.ncsu.edu/aif/index.html)http://www.nice.org.uk/page.aspx?o=43210. AIF facilities include an extensive collection of analytical instrumentation utilized in teaching, research, and in support of academic and industrial programs. General forms of analysis include: electron, ion, and photon microscopies, surface science and analysis, and scanned probe microscopies. An abbreviated listing of AIF capabilities follows: metallography/sample preparation, optical microscopy, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Secondary Ion Mass Spectroscopy (SIMS), Secondary Electron Microscopy (SEM), Scanned Probe Microscopy (SPM), Micro-Raman Spectroscopy, Focused Ion Beam Micro-machining (FIBM), Auger Electron Spectroscopy (AES), and X-Ray Photoelectron Spectroscopy (XPS or ESCA).AIF is a resource utilized not only by those within NC State requiring analytical services, but also by a large number of North Carolina non-profit and industrial organizations as well as the Materials Community at large.

scholarly journals On the early stages of localised atmospheric corrosion of magnesium–aluminium alloys

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Shahabi-Navid ◽  
Y. Cao ◽  
J. E. Svensson ◽  
A. Allanore ◽  
N. Birbilis ◽  
...  
Keyword(s):  
Magnesium Alloys ◽  
Photoelectron Spectroscopy ◽  
Aluminium Alloys ◽  
Atmospheric Corrosion ◽  
Surface Film ◽  
Pure Magnesium ◽  
X Ray Diffraction ◽  
Precipitation Mechanism ◽  
X Ray ◽  
Film Thinning

AbstractThe surface film on pure magnesium and two aluminium-containing magnesium alloys was characterised after 96 h at 95% RH and 22 °C. The concentration of CO2 was carefully controlled to be either 0 or 400 ppm. The exposed samples were investigated using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and electron microscopy. The results showed that when the alloys were exposed to the CO2-containing environment, aluminium cations (Al3+) was incorporated into a layered surface film comprising a partially “hydrated” MgO layer followed by Mg(OH)2, and magnesium hydroxy carbonates. The results indicated that aluminium-containing magnesium alloys exhibited considerably less localised corrosion in humid air than pure magnesium. Localised corrosion in the materials under investigation was attributed to film thinning by a dissolution/precipitation mechanism.

scholarly journals Copper Corrosion in Aqueous Sulfide Solutions under Nuclear Waste Repository Conditions

2012 ◽  
Vol 1475 ◽  
Author(s):  
J. Chen ◽  
Z. Qin ◽  
D. W. Shoesmith
Keyword(s):  
Nuclear Waste ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Film Growth ◽  
Electrochemical Impedance ◽  
Ion Beam ◽  
Chloride Content ◽  
Nuclear Waste Repository ◽  
Copper Corrosion ◽  
X Ray

ABSTRACTThe corrosion behavior of oxygen-free copper in anoxic sulfide solutions under nuclear waste disposal conditions was studied using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) equipped with a focused ion beam (FIB), X-ray photoelectron spectroscopy (XPS) and Micro X-ray diffraction (μXRD). The film growth process and mechanism were elucidated using an Au marker test, and the contribution of solution diffusion to corrosion was demonstrated in magnetically-stirred experiments. The effect of groundwater chemistry, particularly chloride content on copper corrosion and film properties was characterized using long-term corrosion experiments.

Effect of engine oil additives reduction on the tribofilm structure of a cylinder liner model surface

2019 ◽  
Vol 72 (4) ◽  
pp. 515-523
Author(s):  
Maria de Lourdes Miranda-Medina ◽  
Christian Tomastik ◽  
Tia Truglas ◽  
Heiko Groiss ◽  
Martin Jech
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cylinder Liner ◽  
Engine Oil ◽  
Antiwear Additives ◽  
Content Type ◽  
X Ray ◽  
Underlying Mechanisms

Purpose The purpose of this paper is to provide a general picture for describing the formed tribofilm, including chemical and physical aspects in the micro-scale and the nano-scale. In a previous study, the durability of zinc dialkyl dithiophosphate (ZDDP) tribofilms on cylinder liner samples has been investigated in a tribometer model system by using fresh and aged fully formulated oils and replacing them with PAO8 without additives. Analyses of the derived tribofilms by means of X-ray photoelectron spectroscopy and scanning electron microscopy could give some hints about the underlying mechanisms of the tribofilm build-up and wear performance, but a final model has not been achieved. Design/methodology/approach Thus, characterisation of these tribofilms by means of focused ion beam-transmission electron microscopy (FIB-TEM) and energy dispersive X-ray spectroscopy is presented and a concluding model of the underlying mechanisms of tribofilm build-up is discussed in this paper. Findings For tribotests running first with fresh fully formulated engine oil, a rather homogeneous ZDDP-like tribofilm is found underneath a carbon rich tribofilm after changing to non-additivated PAO8. However, when the tests run first with aged fully formulated engine oil, no ZDDP-like tribofilm has been found after changing to non-additivated PAO8, but a wear protective carbon rich tribofilm. Originality/value The obtained results provide insights into the structure and durability of tribofilms. Carbon-based tribofilms are built up on the basis of non-additivated PAO8 because of the previously present ZDDP tribofilms, which suggests an alternative way to reducing the consumption of antiwear additives.

Auger electron spectroscopy and x-ray photoelectron spectroscopy analysis of angle of incidence effects of ion beam nitridation of GaAs

1998 ◽  
Vol 13 (7) ◽  
pp. 1799-1807 ◽  
Author(s):  
J. S. Pan ◽  
C. H. A. Huan ◽  
A. T. S. Wee ◽  
H. S. Tan ◽  
K. L. Tan
Keyword(s):  
Surface Layer ◽  
Auger Electron Spectroscopy ◽  
Angular Dependence ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Incident Angle ◽  
Ion Beam ◽  
X Ray ◽  
Preferential Sputtering

Ion beam nitridation (IBN) of GaAs at room temperature was studied as a function of N2+ ion incident angle at ion energy of 10 keV. The ion beam bombardment surface area of GaAs was characterized in situ by both Auger electron spectroscopy (AES) and small spot-size x-ray photoelectron spectroscopy (XPS). Thin GaN reaction layers are formed at all N2+ ion incident angles, whereas the formation of As–N bonds has not been found. However, the degree of nitridation of Ga decreases with increasing incident angle. The observed angular dependence of the N incorporation can be explained in terms of sputtering yield, indicating that the growth kinetics can be described as a dynamic process comprising the accumulation of N and sputter removal of the surface layer. N2+ ion bombardment causes the depletion of As from the surface region because of the preferential sputtering of As from GaAs. The preferential sputtering of As reduces with increasing N2+ ion incident angle. The angular dependent behavior of preferential sputtering of As by 10 keV N2+ ions can be attributed to the angular dependence of GaN surface layer formation.

The Microstructure Evolution of Corrosion Phenomenon on Aluminum Bond Pads

2005 ◽  
Author(s):  
Jian-Shing Luo ◽  
Hui-Min Lo ◽  
Jeremy D. Russell
Keyword(s):  
Electron Microscopy ◽  
Microstructure Evolution ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
X Ray ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
Layer Structures ◽  
Bond Pads

Abstract X-ray photoelectron spectroscopy (XPS) is a very popular tool for identification of the chemical state of fluorine contamination on aluminum (Al) bond pads. To date, as far as the authors are aware the detailed microstructures of fluorine corrosion on bond pads have not been reported. This paper reports the microstructure evolution of fluorine corrosion on bond pads in a plastic box under specific environment conditions by using transmission electron microscopy (TEM), optical microscopy, focused ion beam and scanning electron microscopy (SEM). The elemental distributions and chemical bonding were performed by using Gatan Image Filter/TEM, energy dispersive X-ray/Scanning TEM (STEM), Auger electron spectroscopy and XPS, respectively. On Al pads with 35 atomic %, fluorine residual, corrosion was observed after around 10 days of storage and became more severe with time. The corrosion layers consist of nano-crystalline and amorphous for both single and double-layer structures.

Silver Metallization with Reactively Sputtered TiN Diffusion Barrier Films

2004 ◽  
Vol 812 ◽  
Author(s):  
L. Gao ◽  
J. Gstöttner ◽  
R. Emling ◽  
Ch. Linsmeier ◽  
M. Balden ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Sheet Resistance ◽  
Diffusion Barrier ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Electrical Measurement ◽  
Silver Layer ◽  
X Ray ◽  
Thermal Stability Of

AbstractThe physical and electrical properties as well as thermal stability of reactively sputtered titanium nitride (TiN) film serving as a diffusion barrier was studied for silver (Ag) metallization. The thermal stability of Ag/TiN metallizations on Si with 12-nm-thick TiN barriers, as-deposited and after annealing at 300-650°C in N2/H2 for 30 min, was investigated with sheet resistance measurement, X-ray diffraction, focused ion beam-scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. According to electrical measurement no change of sheet resistance was found after annealing at 600°C, but an abrupt rise appeared at 650°C annealing. There are two causes by which the Ag/TiN/Si structure became degraded. One is agglomeration of the silver layer, and the other is oxidation and diffusion which are also associated problems during thermal annealing.

3D Observation of Elemental Distribution of Si-Device using a Dedicated FIB/STEM System

2005 ◽  
Author(s):  
T. Yaguchi ◽  
M. Konno ◽  
T. Kamino ◽  
M. Ogasawara ◽  
K. Kaji ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Elemental Distribution ◽  
Multivariate Statistical ◽  
X Ray ◽  
Sample Rotation ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Elemental Maps

Abstract A technique for preparation of a pillar shaped sample and its multi-directional observation of the sample using a focused ion beam (FIB) / scanning transmission electron microscopy (STEM) system has been developed. The system employs an FIB/STEM compatible sample rotation holder with a specially designed rotation mechanism, which allows the sample to be rotated 360 degrees [1-3]. This technique was used for the three dimensional (3D) elemental mapping of a contact plug of a Si device in 90 nm technology. A specimen containing a contact plug was shaped to a pillar sample with a cross section of 200 nm x 200 nm and a 5 um length. Elemental analysis was performed with a 200 kV HD-2300 STEM equipped with the EDAX genesis Energy dispersive X-ray spectroscopy (EDX) system. Spectrum imaging combined with multivariate statistical analysis (MSA) [4, 5] was used to enhance the weak X-ray signals of the doped area, which contain a low concentration of As-K. The distributions of elements, especially the dopant As, were successfully enhanced by MSA. The elemental maps were .. reconstructed from the maps.

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