BRANCHING RATIOS OF THE CIRCULAR-DICHROISM AT RARE-EARTH L-23 EDGES

This paper studies the magnetic circular dichroism (XMCD) at the 20 -- > 5d absorption edges of rare earths. We show that the radial extent o f the 5d orbital is affected not only by the spin but also by the orbi tal part of the df-Coulomb interaction. The resulting changes in the d ipole matrix elements explain the trends in the relative size and sign of the signals at the two spin-orbit split edges. Numerical simulatio ns have been done that include the breathing of the 5d by means of con figuration interaction. (C) 1997 Elsevier Science B.V.