Hydrogen absorption and desorption in Nd2Fe17 and Sm2Fe17

Xiang-Zhong Wang (1) , K. Donnelly (1) , J. M. D. Coey (1) , Bernard Chevalier (2) , Jean Etourneau (2) , Thierry Berlureau (2)

1 Department of Pure and Applied Physics, Trinity College
2 Laboratoire de Chimie du Solide

The uptake of hydrogen by Nd2 Fe17 and Sm2Fe17 has been monitored in a thermopiezic analyser as a function of temperature at an initial pressure of 1 bar (105 Pa). The first stage of hydrogen absorption around 250° C yields R2Fe17H y (R = Nd, Sm) with ~ 2.2; this compound retains the Th2Zn17 structure of the starting alloy but the cell volume is increased by about 3%. The Curie temperature increases from 57 to 175° C for R = Nd and from 115 to 253° C for R = Sm. A second stage of hydrogen absorption at about 600° C corresponds to disproportionation of the alloy into agr-Fe + RH2–epsiv.

Mots clés: Absorption; Samarium; Hydrogen; Neodymium; Inorganic compounds; Curie point; Ferromagnetism

Domaines: Matériaux

Xiang-Zhong Wang, K. Donnelly, J. M. D. Coey, Bernard Chevalier, Jean Etourneau, et al.. Hydrogen absorption and desorption in Nd2Fe17 and Sm2Fe17. Journal of Materials Science, 1988, 23 (1), pp.329-331. ⟨10.1007/BF01174072⟩. ⟨hal-00262094⟩