Structural dependence of the oscillatory exchange interaction across Cu layers

Abstract

A structure-dependent exchange coupling across wedge-shaped Cu layers in fcc (100) Co/Cu/Co and bcc (100) Fe/Cu/Fe epitaxial sandwiches has been determined from analysis of longitudinal magneto-optical Kerr effect hysteresis loops. In the fcc Co/Cu/Co system, the variation of the coupling with Cu thickness can be described as a superposition of two oscillatory terms, with periods of 2.6 and 8.0 monolayers (ML). The bcc Fe/Cu/Fe system shows oscillations with a period of 2 ML. These periodicities are related to the Fermi surface dimensions and topology of fcc and hypothetical bcc bulk Cu.