X-ray magnetic circular dichroism - a universal tool for magnetic investigations

In this paper, we will emphasize that XMCD is a universal tool for studies of magnetism with atomic sensitivity. A quantitative analysis of spin and o rbital momenta is possible, which could be extracted using sum rules develo ped by Thole and Carra. For magnetic investigations, it is possible to meas ure atomic hysteresis loops with high resolution. We will also show that it is feasible to study quantitatively magnetocrystalline anisotropy in compl ex magnetic structures and to understand their microscopic origin in terms of projected orbital momentum distributions and spin-orbit coupling. We dem onstrate that a cubic like anisotropy is present in the colossal magneto re sistance Lanthanummanganates. This could be quantitatively addressed to cha nges in the measured projected orbital moments. In addition, a cubic like a nisotropy was observed in oxygen K edge XMCD hysteresis loops. It is also p ossible to measure quantitatively site selective magnetization profiles in multilayer systems. Therefore, we have developed a magnetic specular hard X -ray diffraction technique. Using the Parratt algorithm. we could extract t he platinum L-3 moment magnetization profile as a function of distance to a ferromagnetic cobalt thin layer. (C) 2001 Elsevier Science B.V. All rights reserved.