Hydrogen absorption properties of amorphous (Ni(0.6)Nb(0.4-)yTay)(100-x)Zr-x membranes
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Authors
Palumbo, Oriele
Trequattrini, F.
Pal, Narendra K.
Hulyalkar, Madhura
Sarker, S.
Chandra, D.
Flanagan, Ted
Dolan, Michael
Paolone, Annalisa
Issue Date
2017
Type
Article
Language
Keywords
Amorphous Ni based alloy ribbons , High temperature X-ray diffraction , DTA , Activation energy , Crystallization temperature , Hydrogen solubility
Alternative Title
Abstract
Ni based amorphous materials have great potential as hydrogen purification membranes. In the present work the melt spun (Ni(0.6)Nb(0.4-)y Tay)(100-)xZrx with y=0, 0.1 and x=20, 30 was studied. The result of X-ray diffraction spectra of the ribbons showed an amorphous nature of the alloys. Heating these ribbons below T < 400 C-circle, even in a hydrogen atmosphere (1-10 bar), the amorphous structure was retained. The crystallization process was characterized by differential thermal analysis and the activation energy of such process was obtained. The hydrogen absorption properties of the samples in their amorphous state were studied by the volumetric method, and the results showed that the addition of Ta did not significantly influence the absorption properties, a clear change of the hydrogen solubility was observed with the variation of the Zr content. The values of the hydrogenation enthalpy changed from similar to 37 kJ/mol for x-30 to similar to 9 kJ/mol for x-20. The analysis of the volumetric data provides the indications about the hydrogen occupation sites during hydrogenation, suggesting that at the beginning of the absorption process the deepest energy levels are occupied, while only shallower energy levels are available at higher hydrogen content, with the available interstitial sites forming a continuum of energy levels.
Description
Citation
Palumbo, O., Trequattrini, F., Pal, N., Hulyalkar, M., Sarker, S., Chandra, D., … Paolone, A. (2017). Hydrogen absorption properties of amorphous (Ni 0.6 Nb 0.4?y Ta y ) 100?x Zr x membranes. Progress in Natural Science: Materials International, 27(1), 126�"131. doi:10.1016/j.pnsc.2017.01.002
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License
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Journal
Volume
Issue
PubMed ID
ISSN
1002-0071