Origin of the X-ray magnetic circular dichroism at the L-edges of the rare-earths in R_x Ŕ₁-x ′al₂ systems

An X-ray magnetic circular dichroism (XMCD) study performed at the rare-earth L 2,3-edges in the R x R 1-x ′Al2 compounds is presented. It is shown that both R and R′ atoms contribute to the XMCD recorded at the L-edges of the selected rare-earth, either R or R′. The amplitude of the XMCD signal is not directly correlated to the magnetization or to the value of the individual (R, R′) magnetic moments, but it is related to the molecular field acting on the rare-earth tuned in the photoabsorption process. This result closes a longstanding study of the origin of the XMCD at the L-edge of the rare-earths in multi-component systems, allowing a full understanding of the exact nature of these signals.