H. Matsuyama et al., ROLES OF 4F-5D EXCHANGE INTERACTIONS IN MAGNETIC CIRCULAR X-RAY DICHROISM AT THE RARE-EARTH L(2,3) EDGES, Journal of the Physical Society of Japan, 66(2), 1997, pp. 337-340
The systematic trend in magnetic circular X-ray dichroism (MCXD) at th
e L(2,3) edges for various rare-earth elements is studied by taking in
to account the effects of the 4f-5d exchange interaction on the electr
ic-dipole transition from the 2p core state to the outermost 5d state.
The exchange interaction gives rise to, in addition to the usual pola
rization effect on the 5d ground state, a novel effect of contraction
in the radial part of the 5d orbits concerned. It is pointed out that,
especially the latter effect, which leads to the enhancement of the t
ransition dipole matrix element depending on the spin and the orbital
momenta of the 5d state, plays a crucial role in successfully interpre
ting the experimental results observed. Quadrupole contributions just
below the edges are also discussed.