The new ternary intermetallic NdNiMg5: hydrogen sorption properties and more

Bassem Ourane (1) , Etienne Gaudin (1) , Yong Feng Lu (2) , Rhida Zouari (3) , Jean-Louis Bobet (1) , Abdelhamid Ben Salah (3)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 Department of Electrical Engineering
3 Département de Chimie

The hydrogen sorption properties of the new compound NdNiMg5 have been investigated. The compound starts to absorb hydrogen at 573 K under a pressure of 1 MPa. The absorption leads to the decomposition into two binary hydrides MgH2 and NdH2.6, and a ternary hydride Mg2NiH4. The maximum hydrogen sorption capacity reached is 3.2 wt.% and the cycling properties of the mixture decreases quickly due to grain growth. The activation energies for absorption and desorption are estimated to be equal to 14(3) kJ/mol H2 and 110(9) kJ/mol H2, respectively. Preliminary studies of the mechanical properties were also performed. Despite the high content in magnesium, NdNiMg5 exhibits an average microhardness of 210 Hv and a reduced Young Modulus of 9(1) GPa.

Mots clés: Inorganic compounds; Electron microscopy; Energy storage; Crystal structure

Domaines: Matériaux

Bassem Ourane, Etienne Gaudin, Yong Feng Lu, Rhida Zouari, Jean-Louis Bobet, et al.. The new ternary intermetallic NdNiMg5: hydrogen sorption properties and more. Materials Research Bulletin, 2015, 61, pp.275-279. ⟨10.1016/j.materresbull.2014.10.026⟩. ⟨hal-01080080⟩