The controlling role of atmosphere in dawsonite versus gibbsite precipitation from tetrahedral aluminate species

2021 ◽  
Vol 50 (38) ◽  
pp. 13438-13446
Author(s):  
Mateusz Dembowski ◽  
John S. Loring ◽  
Mark E. Bowden ◽  
Jacob G. Reynolds ◽  
Trent R. Graham ◽  
...  
Keyword(s):  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray

The transformation of tetrahedrally coordinated potassium aluminate dimer salt to octahedrally coordinated phases, such as gibbsite, is investigated using in situ IR and ex-situ X-ray diffraction, revealing the controlling role of humidity in the presence of CO2.

In Situ X-Ray Diffraction Investigations during Diffusion Anneals of Ni-Cu Thin Film Diffusion Couples

2010 ◽  
Vol 89-91 ◽  
pp. 503-508 ◽  
Author(s):  
J. Sheng ◽  
U. Welzel ◽  
Eric J. Mittemeijer
Keyword(s):  
Thermal Stresses ◽  
Stress Generation ◽  
Ex Situ ◽  
Diffusion Annealing ◽  
X Ray Diffraction ◽  
Individual Layer ◽  
X Ray ◽  
Bilayer System ◽  
Stress Changes

The stress evolution during diffusion annealing of Ni-Cu bilayers (individual layer thicknesses of 50 nm) was investigated employing ex-situ and in-situ X-ray diffraction measurements. Annealing at relatively low homologous temperatures (about 0.3 - 0.4 Tm) for durations up to about 100 hours results in considerable diffusional intermixing, as demonstrated by Auger-electron spectroscopy investigations (in combination with sputter-depth profiling). In addition to thermal stresses due to differences of the coefficients of thermal expansion of layers and substrate, tensile stress con-tributions in the sublayers arise during the diffusion anneals. The obtained stress data have been discussed in terms of possible mechanisms of stress generation. The influence of diffusion on stress development in the sublayers of the diffusion couple during heating and isothermal annealing was investigated by comparing stress changes in the bilayer system with corresponding results obtained under identical conditions for single layers of the components in the bilayer system. The specific residual stresses that emerge due to diffusion between the (sub)layers in the bilayer could thereby be identified.

Size dependent behavior of Fe3O4crystals during electrochemical (de)lithiation: an in situ X-ray diffraction, ex situ X-ray absorption spectroscopy, transmission electron microscopy and theoretical investigation

2017 ◽  
Vol 19 (31) ◽  
pp. 20867-20880 ◽  
Author(s):  
David C. Bock ◽  
Christopher J. Pelliccione ◽  
Wei Zhang ◽  
Janis Timoshenko ◽  
K. W. Knehr ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Changes ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size Dependent ◽  
Transmission Electron ◽  
Dependent Behavior ◽  
X Ray Absorption

Crystal and atomic structural changes of Fe3O4upon electrochemical (de)lithiation were determined.

scholarly journals A study on preparation and characterization of carbon doped TiO2 nanotubes

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Srimala Sreekantan ◽  
Roshasnorlyza Hazan ◽  
Zainovia Lockman ◽  
Ishak Mat
Keyword(s):  
Methyl Orange ◽  
Tio2 Nanotubes ◽  
Pure Tio2 ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Methyl Orange Degradation ◽  
Doped Tio2 ◽  
X Ray ◽  
Carbon Doped

The present study is directed to clarify the influence of carbon doping on the degradation of methyl orange. TiO2 nanotubes were prepared by anodizing titanium foils in a two electrode configuration bath with titanium foil as the anode and platinum as the counter electrode. The electrochemical bathconsists of 1 M Na2SO4 with 0.7 g ammonium fluoride, NH4F. The nanotubes obtained were further doped with carbon via in-situ and ex-situ method. Incorporation of carbon on TiO2 via in-situ method is accomplished during the anodization process by introducing oxalic acid into electrolyte while theex-situ doping involves carbon incorporation into pre-fabricated TiO2 nanotube via flame annealing using carbon blackN330. Characterization such as Scanning Electron Microscope (SEM), Energy Dispersive X-ray Analysis (EDX), and X-Ray Diffraction (XRD) are used to determine the surfacemorphology, composition of dopants, and phases exists. Well ordered nanotube with good adherence and smooth surface was obtained for both methods. When the oxide was annealed, X-ray diffraction analysis revealed the presence of anatase and rutile phase. The photocatalytic properties of thepure TiO2 and carbon doped TiO2 were tested for methyl orange degradation and the result indicated that the in-situ doped TiO2 has much better degradation than the ex-situ and pure TiO2. The percentage of methyl orange degradation for in-situ was 20% and 41% higher than ex-situ doped TiO2 and pure TiO2, respectively.

scholarly journals The Viscosity and Atomic Structure of Volatile-Bearing Melilititic Melts at High Pressure and Temperature and the Transport of Deep Carbon

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 267 ◽  
Author(s):  
Vincenzo Stagno ◽  
Veronica Stopponi ◽  
Yoshio Kono ◽  
Annalisa D’Arco ◽  
Stefano Lupi ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Atomic Structure ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
High Pressure And Temperature ◽  
X Ray ◽  
Falling Sphere ◽  
Basaltic Melts

Understanding the viscosity of mantle-derived magmas is needed to model their migration mechanisms and ascent rate from the source rock to the surface. High pressure–temperature experimental data are now available on the viscosity of synthetic melts, pure carbonatitic to carbonate–silicate compositions, anhydrous basalts, dacites and rhyolites. However, the viscosity of volatile-bearing melilititic melts, among the most plausible carriers of deep carbon, has not been investigated. In this study, we experimentally determined the viscosity of synthetic liquids with ~31 and ~39 wt% SiO2, 1.60 and 1.42 wt% CO2 and 5.7 and 1 wt% H2O, respectively, at pressures from 1 to 4.7 GPa and temperatures between 1265 and 1755 °C, using the falling-sphere technique combined with in situ X-ray radiography. Our results show viscosities between 0.1044 and 2.1221 Pa·s, with a clear dependence on temperature and SiO2 content. The atomic structure of both melt compositions was also determined at high pressure and temperature, using in situ multi-angle energy-dispersive X-ray diffraction supported by ex situ microFTIR and microRaman spectroscopic measurements. Our results yield evidence that the T–T and T–O (T = Si,Al) interatomic distances of ultrabasic melts are higher than those for basaltic melts known from similar recent studies. Based on our experimental data, melilititic melts are expected to migrate at a rate ~from 2 to 57 km·yr−1 in the present-day or the Archaean mantle, respectively.

PHASE FORMATION AND TEXTURE DEVELOPMENT IN AG-SHEATHED Bi, Pb(2223) TAPES STUDIED BY DIFFERENT IN-SITU AND EX-SITU DIFFRACTION TECHNIQUES

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2688-2693 ◽  
Author(s):  
E. GIANNINI ◽  
E. BELLINGERI ◽  
F. MARTI ◽  
M. DHALLÉ ◽  
V. HONKIMÄKI ◽  
...  
Keyword(s):  
High Energy ◽  
Texture Development ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scattering Geometry ◽  
Reflection Geometry ◽  
Comparison Of The Results ◽  
In Situ Neutron Diffraction

In-situ and ex-situ high energy (80÷88 keV) X-Ray diffraction from a synchrotron radiation source were performed on multifilamentary Bi, Pb(2223)/Ag tapes using a transmission scattering geometry. Several thermo-mechanical procedures were compared, focusing mainly on the texture development of both Bi, Pb(2212) and Bi, Pb(2223) phases. The effect of the periodic pressing on the texture and on the critical current is elucidated. The texture development of the Bi, Pb(2212) phase prior to its transformation into Bi, Pb(2223) was directly observed in-situ at high temperature by using a dedicated high-energy X-ray compatible furnace and a high resolution Image Plate detector. A sharp increase of the Bi, Pb(2212) grain orientation along the [00l] direction was found to occur only above 750°C. Normal state transport measurements are in full agreement with the formation mechanism and with the texture development observed. A comparison of the results with the ones provided by in-situ neutron diffraction and standard low-energy XRD in a reflection geometry is presented.

A Combined Experimental and Theoretical Study of Lithiation Mechanism in ZnFe2O4 Anode Materials

MRS Advances ◽  
2018 ◽  
Vol 3 (14) ◽  
pp. 773-778 ◽  
Author(s):  
Lei Wang ◽  
Alison McCarthy ◽  
Kenneth J. Takeuchi ◽  
Esther S. Takeuchi ◽  
Amy C. Marschilok
Keyword(s):  
Early Stage ◽  
Deep Understanding ◽  
Lithium Ion ◽  
Oxidation Products ◽  
Ex Situ ◽  
Theoretical Modelling ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Absorption

ABSTRACTZnFe2O4 (ZFO) represents a promising anode material for lithium ion batteries, but there is still a lack of deep understanding of the fundamental reduction mechanism associated with this material. In this paper, the complete visualization of reduction/oxidation products irrespective of their crystallinity was achieved experimentally through a compilation of in situ X-ray diffraction, synchrotron based powder diffraction, and ex-situ X-ray absorption fine structure data. Complementary theoretical modelling study further shed light upon the fundamental understanding of the lithiation mechanism, especially at the early stage from ZnFe2O4 up to LixZnFe2O4 (x = 2).

(G03 Best Paper Award Winner) Analysis of Sn Behavior During Ni/GeSn Solid-State Reaction by Correlated X-ray Diffraction, Atomic Force Microscopy, and Ex-situ/In-situ Transmission Electron Microscopy

2020 ◽  
Vol MA2020-02 (24) ◽  
pp. 1750-1750
Author(s):  
Andrea Quintero Colmenares ◽  
Patrice Gergaud ◽  
Jean-Michel Hartmann ◽  
Vincent Delaye ◽  
Nicolas Bernier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ex Situ ◽  
Paper Award ◽  
X Ray Diffraction ◽  
Award Winner ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

Development of an in situ synchrotron X-ray total scattering setup under pressurized hydrogen gas

2018 ◽  
Vol 51 (3) ◽  
pp. 796-801 ◽  
Author(s):  
Kouji Sakaki ◽  
Hyunjeong Kim ◽  
Akihiko Machida ◽  
Tetsu Watanuki ◽  
Yoshinori Katayama ◽  
...  
Keyword(s):  
Pair Distribution Function ◽  
Hydrogen Gas ◽  
Ex Situ ◽  
Sample Holder ◽  
Hydrogen Storage Materials ◽  
X Ray Diffraction ◽  
Total Scattering ◽  
X Ray ◽  
Diffraction Patterns

This article describes the development of an in situ gas-loading sample holder for synchrotron X-ray total scattering experiments, particularly for hydrogen storage materials, designed to collect diffraction and pair distribution function (PDF) data under pressurized hydrogen gas. A polyimide capillary with a diameter and thickness of 1.4 and 0.06 mm, respectively, connected with commercially available Swagelok fittings was used as an in situ sample holder. Leakage tests confirmed that this sample holder allows 3 MPa of hydrogen gas pressure and 393 K to be achieved without leakage. Using the developed in situ sample holder, significant background and Bragg peaks from the sample holder were not observed in the X-ray diffraction patterns and their signal-to-noise ratios were sufficiently good. The PDF patterns showed sharp peaks in the r range up to 100 Å. The results of Rietveld and PDF refinements of Ni are consistent with those obtained using a polyimide capillary (1.0 mm diameter and 0.04 mm thickness) that has been used for ex situ experiments. In addition, in situ synchrotron X-ray total scattering experiments under pressurized hydrogen gas up to 1 MPa were successfully demonstrated for LaNi4.6Cu.

In-situ and ex-situ synchrotron X-ray diffraction studies of microstructural length scale controlled dealloying

2019 ◽  
Vol 168 ◽  
pp. 376-392 ◽  
Author(s):  
T. Song ◽  
M. Yan ◽  
N.A.S. Webster ◽  
M.J. Styles ◽  
J.A. Kimpton ◽  
...  
Keyword(s):  
Ex Situ ◽  
Length Scale ◽  
X Ray Diffraction ◽  
X Ray
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