Evaluation of cation migration in lanthanum strontium cobalt ferrite solid oxide fuel cell cathodes via in-operando X-ray diffraction

SEM and in-operando XRD correlate operating conditions, spinel peak shifts, nano-nodule formation, and activation or degradation behavior in LSCF cathodes.

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Polyol-Made Spinel Ferrite Nanoparticles—Local Structure and Operating Conditions: NiFe2O4 as a Case Study

Frontiers in Materials ◽

10.3389/fmats.2021.668994 ◽

2021 ◽

Vol 8 ◽

Author(s):

T. Gaudisson ◽

S. Nowak ◽

Z. Nehme ◽

N. Menguy ◽

N. Yaacoub ◽

...

Keyword(s):

Spinel Phase ◽

Spinel Ferrite ◽

Ferrite Nanoparticles ◽

Operating Conditions ◽

X Ray Diffraction ◽

X Ray ◽

Cation Migration ◽

Anion Vacancies ◽

Nickel Ferrite Nanoparticles ◽

Cation And Anion Vacancies

We report the effect of a polyol-mediated annealing on nickel ferrite nanoparticles. By combining X-ray fluorescence spectroscopy, X-ray diffraction, and 57Fe Mössbauer spectrometry, we showed that whereas the as-prepared nanoparticles (NFO) are stoichiometric, the annealed ones (a-NFO) are not, since Ni0-based crystals precipitate. Nickel depletion from the spinel lattice and reduction in the polyol solvent are accompanied with an important cation migration. Indeed, thanks to Mössbauer hyperfine structure analysis, we evidenced that the cation distribution in NFO departs from the thermodynamically stable inverse spinel structure with a concentration of tetrahedrally coordinated Ni2+ of 20 wt-% (A sites). After annealing, and nickel demixing, originated very probably from the A sites of NFO lattice, the spinel phase accommodates with cation and anion vacancies, leading to the (Fe3+0.84□0.16)A[Ni2+0.80Fe3+1.16□0.04]BO4-0.20 formula, meaning that the applied polyol-mediated treatment is not so trivial.

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Stress-dependent crystal structure of lanthanum strontium cobalt ferrite by in situ synchrotron X-ray diffraction

Journal of Applied Physics ◽

10.1063/1.5017934 ◽

2018 ◽

Vol 123 (7) ◽

pp. 075104 ◽

Cited By ~ 3

Author(s):

Philipp T. Geiger ◽

Neamul H. Khansur ◽

Kevin Riess ◽

Alexander Martin ◽

Manuel Hinterstein ◽

...

Keyword(s):

Crystal Structure ◽

Cobalt Ferrite ◽

X Ray Diffraction ◽

X Ray ◽

Lanthanum Strontium ◽

Stress Dependent

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Multi-Scale Studies of 3D Printed Mn–Na–W/SiO2 Catalyst for Oxidative Coupling of Methane

Catalysts ◽

10.3390/catal11030290 ◽

2021 ◽

Vol 11 (3) ◽

pp. 290

Author(s):

Tim Karsten ◽

Vesna Middelkoop ◽

Dorota Matras ◽

Antonis Vamvakeros ◽

Stephen Poulston ◽

...

Keyword(s):

Oxidative Coupling ◽

Oxidative Coupling Of Methane ◽

Operating Conditions ◽

Homogeneous Distribution ◽

Silica Support ◽

X Ray Diffraction ◽

Cross Sectional ◽

X Ray ◽

Multi Scale ◽

3D Printed

This work presents multi-scale approaches to investigate 3D printed structured Mn–Na–W/SiO2 catalysts used for the oxidative coupling of methane (OCM) reaction. The performance of the 3D printed catalysts has been compared to their conventional analogues, packed beds of pellets and powder. The physicochemical properties of the 3D printed catalysts were investigated using scanning electron microscopy, nitrogen adsorption and X-ray diffraction (XRD). Performance and durability tests of the 3D printed catalysts were conducted in the laboratory and in a miniplant under real reaction conditions. In addition, synchrotron-based X-ray diffraction computed tomography technique (XRD-CT) was employed to obtain cross sectional maps at three different positions selected within the 3D printed catalyst body during the OCM reaction. The maps revealed the evolution of catalyst active phases and silica support on spatial and temporal scales within the interiors of the 3D printed catalyst under operating conditions. These results were accompanied with SEM-EDS analysis that indicated a homogeneous distribution of the active catalyst particles across the silica support.

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Monitoring of Fluctuations in the Physical and Chemical Properties of a High-Calcium Fly Ash

MRS Proceedings ◽

10.1557/proc-113-107 ◽

1987 ◽

Vol 113 ◽

Cited By ~ 8

Author(s):

Scott Schlorholtz ◽

Ken Bergeson ◽

Turgut Demirel

Keyword(s):

Fly Ash ◽

Chemical Properties ◽

Operating Conditions ◽

Physical And Chemical Properties ◽

X Ray Diffraction ◽

X Ray ◽

Morphological Studies ◽

High Calcium ◽

Physical And Chemical ◽

And Chemical Properties

ABSTRACTThe physical and chemical properties of fly ash produced at Ottumwa Generating Station have been monitored since April, 1985. The fly ash is produced from burning a low sulfur, sub-bituminous coal obtained from the Powder River Basin near Gillette, Wyoming. One-hundred and sixty samples of fly ash were obtained during the two year period. All of the samples were subjected to physical testing as specified by ASTM C 311. About one-hundred of the samples were also subjected to a series of tests designed to monitor the self-cementing properties of the fly ash. Many of the fly ash samples were subjected to x-ray diffraction and fluorescence analysis to define the mineralogical and chemical composition of the bulk fly ash as a function of sampling date. Hydration products in selected hardened fly ash pastes, were studied by x-ray diffraction and scanning electron microscopy. The studies indicated that power plant operating conditions influenced the compressive strength of the fly ash paste specimens. Mineralogical and morphological studies of the fly ash pastes indicated that stratlingite formation occurred in the highstrength specimens, while ettringite was the major hydration product evident in the low-strength specimens.

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Structural stability of naphthyl end-capped oligothiophenes in organic field-effect transistors measured by grazing-incidence X-ray diffraction in operando

Organic Electronics ◽

10.1016/j.orgel.2017.07.012 ◽

2017 ◽

Vol 49 ◽

pp. 375-381 ◽

Cited By ~ 10

Author(s):

Mathias K. Huss-Hansen ◽

Andreas E. Lauritzen ◽

Oier Bikondoa ◽

Mika Torkkeli ◽

Luciana Tavares ◽

...

Keyword(s):

Structural Stability ◽

Field Effect ◽

Field Effect Transistors ◽

Grazing Incidence ◽

Organic Field Effect Transistors ◽

X Ray Diffraction ◽

X Ray ◽

In Operando

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Erratum: “New reactor dedicated to in operando studies of model catalysts by means of surface x-ray diffraction and grazing incidence small angle x-ray scattering” [Rev. Sci. Instrum. 78, 083902 (2007)]

Review of Scientific Instruments ◽

10.1063/1.2798532 ◽

2007 ◽

Vol 78 (10) ◽

pp. 109902 ◽

Cited By ~ 2

Author(s):

M.-C. Saint-Lager ◽

A. Bailly ◽

P. Dolle ◽

R. Baudoing-Savois ◽

P. Taunier ◽

...

Keyword(s):

Small Angle ◽

Grazing Incidence ◽

Model Catalysts ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Scattering ◽

In Operando ◽

Operando Studies ◽

Ray Scattering

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Techniques for X-Ray Diffraction Studies of Radioactive Materials

Advances in X-ray Analysis ◽

10.1154/s0376030800000574 ◽

1958 ◽

Vol 2 ◽

pp. 261-274

Author(s):

W. V. Cummings ◽

W. J. Gruber

Keyword(s):

Energy Spectrum ◽

Radiation Damage ◽

Background Level ◽

Operating Conditions ◽

Limiting Factor ◽

X Ray Diffraction ◽

Radioactive Materials ◽

High Background ◽

X Ray

AbstractMany materials, both fissionable and non-fissionable, become very radioactive when subjected to nuclear radiations. This radioactivity results in a high background level in X-ray diffraction studies and becomes a limiting factor in an analysis of radiation damage. A description is given of special techniques that are used to minimize this background and produce optimum diffraction conditions. The radioactive intensity of irradiated X-ray specimens varies from levels that are only mildly troublesome to levels that are extremely hazardous to personnel. The diffraction methods employed at the various levels are explained. An example of the radioactive energy spectrum of a specimen is given to show the method of selecting the best operating conditions and techniques.

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