Ch. Giorgetti

Study of 5d magnetism in rare-earth-transition-metal (Fe, Co) intermetallic compounds by magnetic circular X-ray dichroism

Abstract Magnetic circular X-ray dichroism (MCXD) experiments have been performed at the L 2,3 of rare-earth (RE) elements in several Re-transition-metal (Fe, Co) compounds. Experiments at the L 2,3 edges give, in principle, direct information on the 5d magnetic properties of the RE atom which results from the hybridization between the 3d and the 5d electrons. We show in this paper that the use of MCXD experiments at the L 2,3 absorption edges seems to be really complicated when localized 4f electrons are present in the ground state. This unexpected situation is clearly demonstrated by comparing the results obtained on a cerium mixed-valent compound (CeFe 2 ), in which the 4f electrons are highly hybridized with the conduction electrons, and those obtained on a normal trivalent cerium (4f 1 ) compound (CeRu 2 Ge 2 ). Our results suggest that the 4f electrons play an essential role in the description of MCXD at the edges of rare earths.

RARE-EARTH CONTRIBUTIONS TO THE X-RAY MAGNETIC CIRCULAR DICHROISM AT THE CO K EDGE IN RARE-EARTH-COBALT COMPOUNDS INVESTIGATED BY MULTIPLE-SCATTERING CALCULATIONS

The X-ray magnetic circular dichroism (XMCD) has been measured at the Co K edge in Co-hcp and R-Co compounds (R=La, Tb, Dy). The structure of the experimental XMCD spectra in the near-edge region has been observed to be highly sensitive to the magnetic environment of the absorbing site. Calculations of the XMCD have been carried out at the Co K edge in Co metal, LaCo

Magnetic characteristics of Er(Mn12-xFex) compounds (x=7, 9) determined by X-ray magnetic circular dichroism

_5

Experimental evidence of a strongly reduced orbital moment in CeRh3B2

and TbCo

Evidence of Multielectron Excitations in Magnetic Circular X-ray Dichroism of Rare Earth Compounds

_5

Spin polarisation of copper in Co/Cu and Fe/Cu multilayers

within the multiple-scattering framework including the spin-orbit coupling. In the three systems, the XMCD spectra in the near-edge region are well reproduced. The possibility to separate and quantitatively estimate the local effects from those due to the neighboring atoms in the XMCD cross section makes possible a more physical understanding of the spectra. The present results emphasize the major role played by the

The catalytic centre of transition metal chalcogenides vis-à-vis the oxygen reduction reaction : An in situ electrochemical EXAFS study

d

Magnetic states of iron in metastable fcc Fe–Cu alloys

states of the Tb ions in the XMCD spectrum at the Co K edge in the TbCo

XMCD at LII,III edges of rare-earths: electric quadrupolar and dipolar effects

_5

ptFe3 Invar Studied by High Pressure Magnetic Circular Dichroism

compound.