Dresden 2003 – wissenschaftliches Programm
MA 11.2: Vortrag
Dienstag, 25. März 2003, 12:30–12:45, HSZ/04
Application of the field-induced magnetic circular dichroism to study the magnetic susceptibility of alloys — •Sergey Mankovsky and Hubert Ebert — Dept. Chemie/Phys.Chemie, Universitaet Muenchen, Butenandtstr. 5-13, D-81377 Muenchen, Germany
The magnetic circular dichroism in X-ray absorption (MCXD) is now a standard tool to probe the spin and orbital moments in magnetic materials by exploiting the so-called sum rules. It is the exchange splitting which is responsible for the appearance of MCXD signal in these systems. However, the breaking of time reversal symmetry in the case of non-magnetic materials by introducing the external magnetic field should also result in the appearance of magneto-optical effects. A theoretical description of such experiments for X-ray absorption in the presence of an external magnetic field is presented which is based on a combination of a fully relativistic linear response formalism and a corresponding treatment of magnetic circular dichroism. It is demonstrated that an application of the magnetic sum rules now gives access to the spin and orbital contributions to the element projected susceptibility of the system under investigation. Illustrating examples will be presented for various transition metal alloys, such as AgxPd1−x, AgxPt1−x and RhxPd1−x. Comparison of field-induced XMCD spectra with experiment and comparison of the magnetic susceptibilities calculated directly with those determined from the XMCD spectra on the basis of sum rules show the usefulness and applicability of the new approach.