Hydrogenation inducing antiferromagnetism in the heavy-fermion ternary silicide CeRuSi
RODRÍGUEZ FERNÁNDEZ, Jesus
Departamento de ciencias de la tierra y física de la materia condensada [CITIMAC]
< Réduire
Departamento de ciencias de la tierra y física de la materia condensada [CITIMAC]
Langue
en
Article de revue
Ce document a été publié dans
Physical Review B: Condensed Matter and Materials Physics (1998-2015). 2008, vol. 77, n° 1, p. 014414
American Physical Society
Résumé en anglais
The hydride CeRuSiH1.0 with space group P4/nmm was synthesized by exposure at 523 K of the heavy-fermion ternary silicide CeRuSi under 4 MPa of hydrogen gas. The investigation of the hydride by x-ray powder diffraction ...Lire la suite >
The hydride CeRuSiH1.0 with space group P4/nmm was synthesized by exposure at 523 K of the heavy-fermion ternary silicide CeRuSi under 4 MPa of hydrogen gas. The investigation of the hydride by x-ray powder diffraction reveals that the hydrogenation induces a pronounced anisotropic expansion of the unit cell. Moreover, CeRuSiH1.0 presents two antiferromagnetic transitions at TN1=7.5(2) K and TN2=3.1(2) K evidenced by magnetization and specific heat measurements. Hydrogenation changes the moderate heavy-fermion compound CeRuSi, which has a gamma=220 mJ/mol K2, to an antiferromagnet, which has a smaller electronic coefficient gamma=26 mJ/mol K2. In other words, the hydrogen insertion diminishes the influence of the Kondo effect. The transition heavy-fermion behavior-->antiferromagnet can be well understood in terms of the classical Doniach diagram where the hydrogenation plays a role opposite to the pressure. The expansion of the lattice induced by hydrogen insertion is here much more important than the role of Ce-H bonding observed in other hydrogenated compounds CeCoSiH1.0 or CeCoGeH1.0, where an opposite transition (antiferromagnetic-->spin fluctuation) was evidenced.< Réduire
Mots clés en anglais
Alloys
Heat capacity
Spin glasses and other random magnets
Heavy fermions
Hydride
Cerium
Ruthenium
Silicon
Origine
Importé de halUnités de recherche