Interlayer exchange coupling and giant magnetoresistance in magnetic multilayers

An introduction is given on the subject of magnetic metallic multilayers. These artificial structures appear to display several fascinating physical phenomonena which are of fundamental as well as technological interest. Two examples, the magnetic coupling between ferromagnetic layers across a non-magnetic spacer layer and the giant magnetoresistance are emphasized in this article. For each of these, key experimental observations are reviewed followed by a discussion of the physical principles underlying the phenomenon

Temperature dependence of the resistivity and tunneling magnetoresistance of sputtered FeHf(Si)O cermet films

We have studied the tunneling resistivity and magnetoresistance of reactive sputter deposited FeHfO and FeHfSiO thin granular films. Maximum magnetoresistance ratios at room temperature of 2% and 3.2% were observed for films with compositions of Fe47Hf10O43 and Fe40Hf6Si6O48, respectively. The magnetoresistance shows a decrease with temperature, which cannot be explained by spin-dependent tunneling only. We propose that spin-flip scattering in the amorphous FeHf(Si)O matrix causes this decrease as function of temperature. A two current model for the tunnel magnetoresistance, taking into account spin-flip scattering, is presented which can describe the observed temperature dependence of the magnetoresistance

Biperiodic oscillatory coupling with the thickness of an embedded Ni layer in Co/Cu/Co/Ni/Co (100) and selection rules for the periods

A biperiodic oscillation of the strength of the antiferromagnetic interlayer coupling as a function of the thickness of an embedded Ni layer has been observed in an epitaxial Cu(100)/Co/Cu/Co/Ni/Co sample with the Cu interlayer and the Ni layer in the form of wedges. As the effect originates from Bloch-wave interference in the Ni layer, the observed periods must be, and indeed can be, related to extremal spanning vectors of the spin-resolved Ni Fermi surface. The experiment touches on the selection criteria for spanning vectors of Ni that determine the periods of the oscillations

Interlayer exchange coupling and giant magnetoresistance in magnetic multilayers

An introduction is given on the subject of magnetic metallic multilayers. These artificial structures appear to display several fascinating physical phenomonena which are of fundamental as well as technological interest. Two examples, the magnetic coupling between ferromagnetic layers across a non-magnetic spacer layer and the giant magnetoresistance are emphasized in this article. For each of these, key experimental observations are reviewed followed by a discussion of the physical principles underlying the phenomenon

Interlayer exchange coupling and giant magnetoresistance in magnetic multilayers

An introduction is given on the subject of magnetic metallic multilayers. These artificial structures appear to display several fascinating physical phenomonena which are of fundamental as well as technological interest. Two examples, the magnetic coupling between ferromagnetic layers across a non-magnetic spacer layer and the giant magnetoresistance are emphasized in this article. For each of these, key experimental observations are reviewed followed by a discussion of the physical principles underlying the phenomenon

Interlayer Exchange Coupling and Giant Magnetoresistance in Magnetic Multilayers

An introduction is given on the subject of magnetic metallic multilayers. These artificial structures appear to display several fascinating physical phenomonena which are of fundamental as well as technological interest. Two examples, the magnetic coupling between ferromagnetic layers across a non-magnetic spacer layer and the giant magnetoresistance are emphasized in this article. For each of these, key experimental observations are reviewed followed by a discussion of the physical principles underlying the phenomenon

On the frequency dependence of the magnetic permeability of FeHfO thin films

The frequency dependence of the magnetic permeability as well as of the electrical impedance have been investigated for soft-magnetic granular FeHfO thin films. The impedance measurements indicate that capacitive effects resulting from the inhomogeneous structure of the layers are of no importance for the roll off of the permeability of the present films. The frequency behavior at various FeHfO thicknesses shows that eddy current effects start to play a role above thicknesses of 10 µm. Below this thickness ferromagnetic resonance dominates the roll off