Perpendicular and Parallel Transport, and Interlayer Exchange Coupling in Magnetic Trilayers with Extra Cap-Layers

Oscillations of Magnetoresistance and Interlayer Exchange Coupling Vs. both Non-magnetic Spacer and Cap-layer Thicknesses Are Studied Within the Framework of the S-d Model. the Studies Are Carried Out by Means of the Kubo Formula and a Green Function Recursion Technique. Transport Calculations Concern Multilayers (sandwiched Between Two Semi-infinite Ideal Lead Wires) Oriented Either Parallel Or Perpendicular To the Current Direction. the Considered Structures for the Above Mentioned Two Basic Geometries, Are Cubic Grains Identical In: (i) Size, (ii) Number of Sublayers, and (iii) Thicknesses of Particular Sublayers, Which Makes It Possible To Compare, in a Direct and Reliable Way, the Corresponding Magnetoresistances. the Current-in-plane Magnetoresistance Is Found To Be Usually Lower Than the Current-perpendicular-to-plane One, But Both of Them Show Oscillatory Behaviours Mutually Correlated, and Related To the Fermi Surface Callipers. moreover, the Current-perpendicular-to-plane Giant Magnetoresistance for Structures in a Form of Infinite in Layer-plane Trilayers Capped with An Extra Bilayer (ferromagnet/paramagnet) Is Also Discussed.