Influence of hydrogenation on the structural and magnetic properties of compounds based on cerium and crystallizing in the tetragonal CeFeSi-type structure

Bernard Chevalier (1) , Mathieu Pasturel (1) , Jean-Louis Bobet (1) , Olivier Isnard (2)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 Laboratoire de Cristallographie

The hydrogen absorption properties of CeMnGe, CeFeSi and CeCoX (X=Si and Ge) have been investigated. Neutron powder diffraction performed on deuteride CeCoGeD indicates that D-atoms are inserted in the pseudo-tetrahedral interstices [Ce4] of the tetragonal CeFeSi-type structure of this compound. Magnetization and electrical resistivity measurements reveal that the hydrogenation of: (i) CeCoSi and CeCoGe leads to the transition antiferromagnet→spin fluctuation behaviour; (ii) CeMnGe suppress the magnetic ordering of the Ce-moments. These results which suggest a lost of ordered magnetic moment on the Ce site after hydrogenation could result from the chemical effect of hydrogen which prevails over the unit cell expansion effect.

Mots clés: Magnetically ordered materials; Valence fluctuations

Domaines: Matériaux

Bernard Chevalier, Mathieu Pasturel, Jean-Louis Bobet, Olivier Isnard. Influence of hydrogenation on the structural and magnetic properties of compounds based on cerium and crystallizing in the tetragonal CeFeSi-type structure. Solid State Communications, 2005, 134 (8), pp.529-533. ⟨10.1016/j.ssc.2005.02.040⟩. ⟨hal-00022430⟩