Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9817656 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2005 | 4 Pages |
Abstract
The effects of hydrogen absorption on the crystalline and magnetic properties of the γ-phase Y2Co7H6 were examined by bulk magnetic measurements, neutron diffraction and X-ray absorption spectroscopy. An orthorhombic distortion of the unit cell occurs upon hydrogen insertion, accompanied by a reduction of the magnetic moment on Co and a decrease of the ordering temperature. Magnetic measurements indicate a metamagnetic transition occurring in the γ-phase hydride. The transition shows a broad hysteresis and the magnitude of the critical field is found to decrease with increasing temperature. The electronic structure of Co in Y2Co7 and Y2Co7H6 has been investigated by X-ray absorption spectroscopy. The observed decrease of the pre-peak intensities in the Co-K edge XANES spectra are related to the changes of the 4p-3d density of states upon hydrogen insertion. A comparative X-ray magnetic circular dichroism investigation at the Co-K edge has been carried out for Y2Co7 and Y2Co7H6. The observed XMCD signal enables us to propose that ferromagnetic ordering occurs in the γ-hydride.
Related Topics
Physical Sciences and Engineering
Materials Science
Surfaces, Coatings and Films
Authors
Olivier Isnard, Claudia Zlotea, François Baudelet,