CIRCULAR MAGNETIC-X-RAY DICHROISM FOR RARE-EARTHS

Circular magnetic x-ray dichroism is a promising new tool for the stud y of spin and orbital moments in ferromagnetically ordered materials. For rare-earth systems the L(2) and L(3) edge dichroic spectra give in formation about the magnetic properties of the 5d conduction electrons . This article addresses a few of the key issues concerning the interp retation of the spectra. In particular, the quadrupole nature of the d ichroic spectra below the L absorption edges and its angular dependenc e is discussed. The important role of the 4f-5d exchange in causing a large and important spin dependence in the 2p-5d matrix elements is li kewise examined.