C. Blaas

The CPP transport in metallic magnetic multilayers

The transmission matrix approach is used to evaluate perpendicular magnetotransport in metallic multilayers that consist of two magnetic slabs separated by a non-magnetic spacer. We employ the spin-polarized surface Green function technique within the framework of the tight-binding linear muYn-tin orbital method. Our approach allows both the ballistic and the diVusive regime of magnetotransport to be treated on equal footing. The eVect of disorder is included in terms of lateral supercells confined to individual atomic layers. In this paper, we apply the method to fcc-based Co/Cu/Co(001) trilayers.

Magnetic properties, interlayer exchange coupling and electric transport in Fe/Cr/Fe trilayers

Abstract Based on the fully relativistic spin-polarized screened Korringa-Kohn-Rostoker method and the Kubo-Greenwood eauation as formulated for layered systems the interlayer exchange coupling (IEC) as well as the magneto-resistance (MR) for the current in-plane (CIP) geometry is calculated for Fe/Cr/ Fe trilayer systems. For the IEC not only short periods of 2 monolayers (ML) but also long periods of about 18 ML are found. For large Cr thicknesses the magnetic moments oscillate with a period of 8-9 ML for even numbers of Cr layers and 18 for odd. The calculated CIP MR and corresponding resistivities are in the range of available experimental data. It is found that the peaks in the CIP MR have little in common with the oscillation periods characterizing the IEC.

AB-INITIO THEORY OF THE CPP-MAGNETOCONDUCTANCE*)

The current-perpendicular-to-plane (CPP) magnetoconductance of a trilayer consisting of a spacer sandwiched between two ideal leads is described on anab initio level. We employ the transmission matrix formulation of the conductance within the framework of the spin-polarized surface Green function technique as formulated in terms of the tight-binding linear muffin-tin orbital method. The formalism is extended to the case of lateral supercells in each layer with random arrangements of atoms which allows to treat both the ballistic and diffusive transports on equal footing. The application is made to fcc-based Co/Cu/Co(001) trilayers.

Ab Initio Theory of Perpendicular Transport in Metallic Magnetic Multilayers

The current-perpendicular-to-plane (CPP) magnetoconductance of a sample sandwiched by two ideal non-magnetic leads is described at an ab initio level. The socalled ‘active’ part of the system is a trilayer consisting of two magnetic slabs of finite thickness separated by a non-magnetic spacer. We use a transmission matrix formulation of the conductance based on surface Green functions as formulated by means of the tight-binding linear muffin-tin orbital method. An equivalent and computationally more efficient formulation of the problem based on reflection matrices is also presented. The formalism is extended to the case of lateral supercells with random arrangements of atoms which in turn allows to deal with ballistic and diffusive transport on equal footing. Applications refer to fcc-based Co/Cu/Co(001) trilayers.