Structure and hydrogenation study of nickel substituted NdCo3NiB
Langue
en
Article de revue
Ce document a été publié dans
Journal of Alloys and Compounds. 2012, vol. 526, p. 63-67
Elsevier
Résumé en anglais
In an attempt to observe hydrogen (deuterium) induced atomic ordering of transition (T) metals in AB5-type derivative structures neutron diffraction and hydrogen cycling experiments were performed on a nickelsubstituted ...Lire la suite >
In an attempt to observe hydrogen (deuterium) induced atomic ordering of transition (T) metals in AB5-type derivative structures neutron diffraction and hydrogen cycling experiments were performed on a nickelsubstituted boride sample of composition NdCo3NiB. While uncycled NdCo3NiB crystallizes with the centrosymmetric CeCo4B-type structure (space group P6/mmm), hydrogenation (deuteration) and cycling of NdCo3NiB at 373 K between 0 and 60 bar hydrogen (deuterium) atmosphere induces a symmetry decrease to non-centrosymmetric space group P6mm. Evidence for partial cobalt/nickel ordering is found in pristine NdCo3NiB but not in its deuteride NdCo3NiBDx. Compared to boron free AB5-type compounds deuterium occupies only those interstices that have no boron atom in their coordination sphere. These findings are consistent with repulsive B-D interactions. At 303 K the hydrogen equilibrium plateau pressure of the NdCo3NiB-H system is about 2 bar, and the hydrogen content at 10 bar is about 3.1 H atoms per formula unit.< Réduire
Mots clés en anglais
Rare earth alloys
Hydrogen storage materials
Crystal structure
Neutron diffraction
Origine
Importé de halUnités de recherche