Cyclic Oxidation of Two FeCrAlRE Foils at 1100 °C - The Influence of the Concentration of Minor Alloying Elements on Scale Microstructure

2008 ◽  
Vol 595-598 ◽  
pp. 707-716 ◽  
Author(s):  
Fang Liu ◽  
Helena Götlind ◽  
Sead Canovic ◽  
Hai Ping Lai ◽  
Jörgen Westlinder ◽  
...  
Keyword(s):  
Cyclic Oxidation ◽  
Grazing Incidence ◽  
Model Alloy ◽  
X Ray Diffraction ◽  
Oxide Interface ◽  
X Ray ◽  
Thin Foils ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Α Al2o3

Two FeCrAlRE alloys, a commercial, 0C404, and a model alloy in the form of thin foils, with different Mn, Nb, Mo and Ti concentrations were subjected to cyclic oxidation in lab air at 1100°C. The oxidized samples were studied by gravimetry, Grazing-Incidence X-ray Diffraction (GI-XRD), Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive X-ray (EDX) analysis. The two FeCrAl alloys exhibit different oxidation kinetics; however, both alloys have the same weight gain after 500 hours exposure. During the early stages the scale consists mainly of α-Al2O3 together with some oxide particles containing Mn, Al, Fe and Cr formed on the alloys. After 500 hours the 0C404 scale locally also consists of larger polycrystalline regions of Mn-Cr-Al spinel. In addition, Si-rich oxide, chromia and Al-Cr oxide could be observed at the metal/oxide interface.

scholarly journals Evolution of Corrosion Products Formed during the Corrosion of MgZr Alloy in Poral Solutions Extracted from Na-Geopolymers Used as Conditioning Matrix for Nuclear Waste

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4958
Author(s):  
Rémi Boubon ◽  
Xavier Deschanels ◽  
Martiane Cabié ◽  
Diane Rébiscoul
Keyword(s):  
Grazing Incidence ◽  
Corrosion Products ◽  
Fuel Cladding ◽  
X Ray Diffraction ◽  
Dissolved Silica ◽  
X Ray ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Potential Matrix

Geopolymer, a nanoporous aluminosilicate filled with water and ions, has been selected as a potential matrix to encapsulate MgZr alloy fuel cladding. In this study, we investigate the evolution of the corrosion products formed during the corrosion of MgZr in poral solutions extracted from geopolymers with and without NaF as corrosion inhibitor. Using various characterization techniques such as Scanning Electron and Scanning Transmission Electron Microscopies coupled to Energy Dispersive X-ray spectroscopy and Grazing Incidence X-ray Diffraction, we show that the amounts of dissolved silica and fluoride species in solution are the key parameters driving the nature of corrosion products and probably their passivating properties regarding MgZr corrosion.

scholarly journals Surface Stoichiometry and Depth Profile of Tix-CuyNz Thin Films Deposited by Magnetron Sputtering

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3191
Author(s):  
Arun Kumar Mukhopadhyay ◽  
Avishek Roy ◽  
Gourab Bhattacharjee ◽  
Sadhan Chandra Das ◽  
Abhijit Majumdar ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Relative Composition ◽  
Transmission Electron ◽  
Deposited Film ◽  
Deposited Films

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.

An X-ray scattering study on inverted Ge–Si huts grown at low temperatures

2004 ◽  
Vol 19 (4) ◽  
pp. 347-351
Author(s):  
J. Xu ◽  
X. S. Wu ◽  
B. Qian ◽  
J. F. Feng ◽  
S. S. Jiang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Lattice Strain ◽  
Lattice Mismatch ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Large Lattice ◽  
Scattering Study

Ge–Si inverted huts, which formed at the Si∕Ge interface of Si∕Ge superlattice grown at low temperatures, have been measured by X-ray diffraction, grazing incidence X-ray specular and off-specular reflectivities, and transmission electron microscopy (TEM). The surface of the Si∕Ge superlattice is smooth, and there are no Ge–Si huts appearing on the surface. The roughness of the surfaces is less than 3 Å. Large lattice strain induced by lattice mismatch between Si and Ge is found to be relaxed because of the intermixing of Ge and Si at the Si∕Ge interface.

Phase Transformation of Powdered Material by Using Metal Jet

2012 ◽  
Vol 706-709 ◽  
pp. 741-744 ◽  
Author(s):  
Akio Kira ◽  
Ryuichi Tomoshige ◽  
Kazuyuki Hokamoto ◽  
Masahiro Fujita
Keyword(s):  
Phase Transformation ◽  
Powdered Material ◽  
Scanning Transmission Electron Microscope ◽  
Ultrahigh Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Metal Jet ◽  
Very High

The various techniques of phase transformation of the material have been proposed by many researchers. We have developed several devices to generate the ultrahigh pressure by using high explosive. One of them uses metal jets. It is expected that the ultrahigh pressure occurs by the head-on collision between metal jets, because the velocity of the metal jet is very high. By mixing a powdered material with metal jets, the pressure of the material becomes high. The purpose of this study is to transform the phase of the powdered material by using this high pressure. The powders of the graphite and hBN were applied. The synthesis to the diamond and cBN was confirmed by X-ray diffraction (XRD). In this paper, the mechanism of the generation of the ultrahigh pressure is explained and the results of the observation of the powder by using scanning transmission electron microscope (STEM) are reported.

Core–shell structures with metallic silver as nucleation agent of low expansion phases in BaO/SrO/ZnO/SiO2 glasses

CrystEngComm ◽  
2019 ◽  
Vol 21 (29) ◽  
pp. 4373-4386 ◽  
Author(s):  
Christian Thieme ◽  
Michael Kracker ◽  
Katrin Thieme ◽  
Christian Patzig ◽  
Thomas Höche ◽  
...  
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Nucleating Agent ◽  
Shell Structures ◽  
Metallic Silver ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission

The role of silver as a nucleating agent in BaO/SrO/ZnO/SiO2 glasses is studied with a range of microstructure-characterization techniques, such as scanning transmission electron microscopy, ultraviolet-visible spectroscopy, and X-ray diffraction.

In situ x-ray study of the γ- to α-Al2O3 phase transformation during atmospheric pressure oxidation of NiAl(110)

2006 ◽  
Vol 21 (12) ◽  
pp. 3047-3057 ◽  
Author(s):  
A. Vlad ◽  
A. Stierle ◽  
N. Kasper ◽  
H. Dosch ◽  
M. Rühle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Orientation Relationship ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Oxidation In Air ◽  
Α Al2o3 ◽  
Underlying Substrate

The oxidation in air of NiAl(110) was investigated in the temperature range from 870 °C–1200 °C by in situ x-ray diffraction and transmission electron microscopy. Oxidation at 870 °C and 1 bar oxygen leads to the formation of an epitaxial layer of γ-alumina showing an R30° orientation relationship with respect to the underlying substrate. At oxidation temperatures between 950 °C and 1025 °C, we observed a coexistence of epitaxial γ- and polycrystalline δ-Al2O3. The α-Al2O3 starts to form at 1025 °C and the complete transformation of metastable phases to the stable α-alumina phase takes place at 1100 °C. The fcc-hcp martensitic-like transformation of the initial γ-Al2O3 to epitaxial α-Al2O3 was observed. X-ray diffraction and cross-section transmission electron microscopy proved the existence of a continuous epitaxial α-Al2O3 layer between the substrate and the polycrystalline oxide scale, having a thickness of about 150 nm. The relative orientation relationship between the epitaxial alumina and the underlying substrate was found to be NiAl(110) || α-Al2O3 (0001) and [110] NiAl || [1120].

Obtaining the structure factors for an epitaxial film using Cu X-ray radiation

2013 ◽  
Vol 46 (6) ◽  
pp. 1749-1754 ◽  
Author(s):  
P. Wadley ◽  
A. Crespi ◽  
J. Gázquez ◽  
M.A. Roldán ◽  
P. García ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Structure Factor ◽  
Tetragonal Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Factors ◽  
Scanning Transmission

Determining atomic positions in thin films by X-ray diffraction is, at present, a task reserved for synchrotron facilities. Here an experimental method is presented which enables the determination of the structure factor amplitudes of thin films using laboratory-based equipment (Cu Kα radiation). This method was tested using an epitaxial 130 nm film of CuMnAs grown on top of a GaAs substrate, which unlike the orthorhombic bulk phase forms a crystal structure with tetragonal symmetry. From the set of structure factor moduli obtained by applying this method, the solution and refinement of the crystal structure of the film has been possible. The results are supported by consistent high-resolution scanning transmission electron microscopy and stoichiometry analyses.

scholarly journals Synthesis and Structure of novel Luminescent lanthanide organic frameworks.

2014 ◽  
Vol 70 (a1) ◽  
pp. C1259-C1259
Author(s):  
Mohammed S. M. Abdelbaky ◽  
Zakariae Amghouz ◽  
Santiago Granda
Keyword(s):  
Thermal Analyses ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Carboxylate Groups ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Conventional Electrode ◽  
Li Ion

Lanthanide-Organic frameworks (LnOFs) are currently attracting increasing attention due to their excellent luminescence properties, in which both Ln3+ and organic linkers can be used to give rise to luminescence materials with increased brightness and emission quantum yield [1,2]. Lithium doped MOFs are of particular interest due to the recent studies showing enhanced H2 uptake, as well as promising candidates for replacing the conventional electrode in Li-ion batteries [3,4]. Herein, novel Lithium-lanthanide frameworks based on a rigid dicarboxylic acid, formulated as [LiLn(BDC)2(H2O)·2(H2O)] (Ln = Y, Dy, Ho, Er, Yb, Y1-xEux, Y1-xTbx and H2BDC = Terephthalic acid), have been obtained as single phases under hydrothermal conditions. The crystal structures were solved by single-crystal X-ray diffraction and the bulk characterized by powder X-ray diffraction (PXRD), thermal analyses (TG-MS and DSC), vibrational spectroscopy (FTIR), scanning/transmission electron microscopy (SEM-EDX, TEM, SAED, STEM-EDX), and powder X-ray thermodiffractometry (HT-XRD). All compounds are isostructural (monoclinic P21/c, a = 11.6365(7) Å, b =16.0920(2) Å, c = 13.2243(8) Å and β = 132.23(1)° for Ln = Y [5]) and possess a 3D framework with 1D trigonal channels running along the [101] direction contain water molecules. The structure is built up of unusual four-membered rings formed by edge- and vertex-shared {LnO8} and {LiO4} polyhedra. The four-membered rings are isolated and connected to each other via carboxylate groups. Topologically, the 3D frameworks belongs to a new 2-nodal 3,10-c net with point symbol of {4.5^2}2{4^14.5^10.6^18.7.8^2}. HT-XRD reveals that the compounds undergo phase transformation upon dehydration process which is a reversible process involving a spontaneous rehydration characterized by fast kinetic. The luminescence properties of selected compounds are also studied.

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