Hydrogenation as an instrument for modifying structures and properties of certain classes of intermetallics and inorganic metal-rich compounds
Final Report Abstract
This research program has been focused on further developing hydrogenation as an instrument for modifying structures and properties of intermetallic metal-rich compounds, investigating the fundamental principles of hydrogen insertion, and establishing structure-property relationships for such metal hydrides and chemical ways of their manipulation. Bond systems based on d- and f- metals offer numerous possibilities for different varieties of element combinations and changes in bonding patterns are usually poorly understood. The influence of hydrogen insertion on the structures and properties of the following classes of intermetallic compounds has been investigated: MNi3 compounds with M as a transition metal (M = Ti, Zr, V, Fe) or a p-block element (M = Al, Ga, In, Si, Ge, Sn, Sb), FePd3, MgPd2 and LnTiGe (Ln = Ce, La, Nd) -“111”- type compounds. Characterization of the compounds has been based on X-ray and neutron powder diffraction investigations, (including in situ studies), electron microscopy, microprobe analysis, and thermal analysis measurements. Several of the investigated systems, MNi3 (M = Al, Ga, In, Sn), show a reaction towards hydrogen correlated with a significant hydrogen-induced volume increase of the unit cell. The refined crystal structures of Ni3AlHx, Ni3GaHx, β-Ni3InHy, β-Ni3SnHy, α-Ni3InHx, and α-Ni3SnHx have suitable [Ni6] octahedral sites for hydrogen incorporation and the amount of [Ni6] octahedral voids per formula unit and the isolation of them to avoid possible H–H interactions plays an important role.
Publications
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Hydrogen-Induced Order–Disorder Effects in FePd3. Crystals, 12(12), 1704.
Götze, André; Stevenson, Siobhan Christina; Hansen, Thomas Christian & Kohlmann, Holger
