scholarly journals In Situ Synchrotron X-ray Diffraction Studies of Hydrogen-Desorption Properties of 2LiBH4–Mg2FeH6 Composite

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4853
Author(s):  
Mohammad R. Ghaani ◽  
Michele Catti ◽  
Niall J. English
Keyword(s):  
Reaction Path ◽  
Hydrogen Desorption ◽  
Hydrogen Atmosphere ◽  
Molar Ratio ◽  
Isothermal Decomposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dehydrogenation Reactions ◽  
Dynamic Decomposition

Adding a secondary complex metal hydride can either kinetically or thermodynamically facilitate dehydrogenation reactions. Adding Mg2FeH6 to LiBH4 is energetically favoured, since FeB and MgB2 are formed as stable intermediate compounds during dehydrogenation reactions. Such “hydride destabilisation” enhances H2-release thermodynamics from H2-storage materials. Samples of the LiBH4 and Mg2FeH6 with a 2:1 molar ratio were mixed and decomposed under three different conditions (dynamic decomposition under vacuum, dynamic decomposition under a hydrogen atmosphere, and isothermal decomposition). In situ synchrotron X-ray diffraction results revealed the influence of decomposition conditions on the selected reaction path. Dynamic decomposition of Mg2FeH6–LiBH4 under vacuum, or isothermal decomposition at low temperatures, was found to induce pure decomposition of LiBH4, whilst mixed decomposition of LiBH4 + Mg and formation of MgB2 were achieved via high-temperature isothermal dehydrogenation.

scholarly journals In-Situ X-ray Diffraction Measurement for Pure Niobium Metal in High Temperature Hydrogen Atmosphere

2006 ◽  
Vol 70 (6) ◽  
pp. 467-472 ◽  
Author(s):  
Tomonori Nambu ◽  
Nobue Shimizu ◽  
Hisakazu Ezaki ◽  
Hiroshi Yukawa ◽  
Masahiko Morinaga ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Atmosphere ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Niobium

Hydrogen desorption properties of melt-spun and hydrogenated Mg-based alloys using in situ synchrotron X-ray diffraction and TGA

2011 ◽  
Vol 509 ◽  
pp. S629-S632 ◽  
Author(s):  
Siarhei Kalinichenka ◽  
Lars Röntzsch ◽  
Carsten Baehtz ◽  
Thomas Weißgärber ◽  
Bernd Kieback
Keyword(s):  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melt Spun

In Situ X-ray Absorption Spectroscopy–X-ray Diffraction Investigation of Nb–H Nanoclusters in MgH2 during Hydrogen Desorption

2015 ◽  
Vol 119 (14) ◽  
pp. 7765-7770 ◽  
Author(s):  
C. Maurizio ◽  
R. Checchetto ◽  
A. Trapananti ◽  
A. Rizzo ◽  
F. D’Acapito ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Absorption

In-situ observation on the isothermal decomposition process of γ-Fe[N] by X-ray diffraction

2008 ◽  
Vol 202 (12) ◽  
pp. 2638-2643 ◽  
Author(s):  
Zhi-Jun Jiang ◽  
Xiao-Ling Li ◽  
Jian-Feng Gu ◽  
Ming-Juan Hu ◽  
Zu-Chang Zhu
Keyword(s):  
Decomposition Process ◽  
In Situ Observation ◽  
Isothermal Decomposition ◽  
X Ray Diffraction ◽  
X Ray

[Ca (2,2′-Bipyridine)3]2+-Intercalated Montmorillonite: An Application as Potentiometric Sensor

2012 ◽  
Vol 428 ◽  
pp. 7-13 ◽  
Author(s):  
S. Payungsak ◽  
Atchana Wongchaisuwat ◽  
Ladda Meesuk
Keyword(s):  
Interlayer Space ◽  
C:N Ratio ◽  
Potentiometric Sensor ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
X Ray ◽  
Artificial Graphite ◽  
Higher Sensitivity

This article involves the use of [Ca (2,2′-bipyridine)3]2+-intercalated montmorillonite as a potentiometric sensor to measure anions in aqueous solution. The [Ca (2,2′-bipyridine)3]2+-intercalated montmorillonite was prepared by modification of an in situ solid-solid reaction, between natural Ca (II)-montmorillonite and 2,2′-bipyridine at a molar ratio 1:3. The formation of [Ca (2,2′-bipyridine)3]2+- in the interlayer space of montmorillonite was confirmed by powder X-ray diffraction (XRD) and the existence of 2,2′-bipyridine was confirmed by the C:N ratio of the product compared with that of the 2,2′-bipyridine molecule. The potentiometric sensor was constructed by mixing [Ca (2,2′-bipyridine)3]2+-intercalated montmorillonite with artificial graphite, polytetrafluoroethylene (PTFE) and carboxymethylcellulose (CMC) in an appropriate ratio. It was found that the sensor had higher sensitivity to S2- rather than other anions, graphs of log [S2-] vs voltage (mv) gave a slope 30.0 which was closed to theoretical value, 29.5. Activity of the [Ca (2,2′-bipyridine)3]2+ sensor was verified by using sensor made from Ca (II)-montmorillonite as a reference. Reproducibility and precision of the electrode were also determined.

In situ synchrotron X-ray diffraction studies of hydrogen desorption and absorption properties of Mg and Mg–Mm–Ni after reactive ball milling in hydrogen

2009 ◽  
Vol 57 (13) ◽  
pp. 3989-4000 ◽  
Author(s):  
R.V. Denys ◽  
A.B. Riabov ◽  
J.P. Maehlen ◽  
M.V. Lototsky ◽  
J.K. Solberg ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
X Ray ◽  
Milling In Hydrogen

pH-Controlled Assembly of 3D and 2D Zinc-based Metal-Organic Frameworks with Tetrazole Ligands

2017 ◽  
Author(s):  
Felipe Herrera ◽  
Ignacio Chi-Duran ◽  
Javier Enriquez ◽  
Carolina Manquian ◽  
Kerry Wrighton-Araneda ◽  
...  
Keyword(s):  
Structural Diversity ◽  
Molar Ratio ◽  
Aqua Complex ◽  
Initial Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Metal Organic ◽  
Metal Ligand

<div> <div> <div> <p>We report the synthesis and structural diversity of Zn(II) MOF with in situ formation of tetrazole ligand 3-ptz [3-ptz = 5-(3-pyridyl)tetrazolate], as a function pH. By varying the initial reaction pH, we obtain high-quality crystals of the non-centrosymmetric 3D MOF Zn(3-ptz)2, mixed phases involving the zinc-aqua complex [Zn(H2O)4(3-ptz)2]·4H2O, and 2D MOF crystals Zn(OH)(3-ptz) with a tunable micro-rod morphology, keeping reaction time, temperature and metal-ligand molar ratio constants. Structures are characterized by X-ray diffraction, scanning electron microscopy, FTIR and UV-Vis spectroscopy. We discuss the observed structural diversity in terms of the relative abundance of hydroxo-zinc species in solution for different values of pH. </p> </div> </div> </div>

Effects of In-Situ DC-Bias on the Composition, Microstructures and Dielectric Properties of RF Magnetron Reactive Sputtered (Ba,Sr)TiO3 Films

1999 ◽  
Vol 596 ◽  
Author(s):  
Wen-Hao Chan ◽  
Hui-Ling Shen ◽  
Lih-Hsin Chou ◽  
Jinn-Lung Wang ◽  
Jyi-Ching Tsai
Keyword(s):  
Dielectric Constant ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
Alloy Target ◽  
Bst Films ◽  
Dc Bias ◽  
Diffraction Patterns

AbstractThin films of (Ba,Sr)TiO3 (BST) have been prepared by rf magnetron reactive sputtering using single alloy target, and in-situ negative DC-bias. Post annealing was applied to the asdeposited films at 620°C for 2 hours in 1 atm oxygen atmosphere. Thin film microstructures and grain sizes were studied and calculated by means of X-ray diffraction, while the film composition was analyzed by Electron Probe X-ray Microanalyzer (EPMA). The dielectric constant of the films was also studied. As the applied DC-bias increased, the dielectric constant increased from 176 to 912, the x-ray diffraction patterns became more intense and narrower, and the (Ba+Sr)/Ti molar ratio increased from 0.70 to 0.83. In-situ DC-bias was observed to be a feasible fabrication process to increase the grain size and relative permittivity of sputtered BST films.

Hydrogen-induced structural transformation of AuCu nanoalloys probed by synchrotron X-ray diffraction techniques

Nanoscale ◽  
2014 ◽  
Vol 6 (8) ◽  
pp. 4067-4071 ◽  
Author(s):  
M. Yamauchi ◽  
K. Okubo ◽  
T. Tsukuda ◽  
K. Kato ◽  
M. Takata ◽  
...  
Keyword(s):  
Structural Transformation ◽  
Hydrogen Atmosphere ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Face Centered

In situ X-ray diffraction measurements reveal that the transformation of a AuCu nanoalloy from a face-centered-cubic to an L10 structure is accelerated under a hydrogen atmosphere.

Formation of Cu2ZnSnS4 and Cu2ZnSnS4-CuInS2 Thin Films Investigated by In-Situ Energy Dispersive X-Ray Diffraction

2007 ◽  
Vol 1012 ◽  
Author(s):  
Alfons Weber ◽  
Immo Kötschau ◽  
Susan Schorr ◽  
Hans-Werner Schock
Keyword(s):  
Thin Films ◽  
Reaction Path ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Effects ◽  
Cuins2 Thin Films ◽  
Diffraction Peaks ◽  
Poor Adhesion

AbstractChalcopyrite CuInS2 and the structurally related kesterite Cu2ZnSnS4 are known as photovoltaic absorber materials. In this study different precursor thin films of the quaternary Cu-Zn-Sn-S system (stacking: Mo/CuS/ZnS-SnS) and of the pentenary Cu-In-Zn-Sn-S system (stacking: Mo/CuIn/ZnS-SnS) were annealed in sulfur atmosphere. The predominant crystalline phases were detected by in-situ energy dispersive X-ray diffraction (EDXRD). Additionally the X-ray fluorescence signals of the film components were recorded to detect diffusion effects. For the quaternary system we found ZnS, CuS, Cu2-xS, Sn2S3 and SnS as main binary phases during annealing. The Sn2S3-SnS phase transition had a significant impact on the later formation of ternary/quaternary phases. A high diffusivity of copper can explain the little influence of the precursor stacking on the reaction path and may also be responsible for the poor adhesion of the films. For annealing temperatures above 450°C Cu2ZnSnS4 can be identified clearly by XRD. The incorporation of indium in the system leads to new diffraction peaks which can be explained by the formation of solid solutions in the system CuInS2-Cu2ZnSnS4.

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