Giant Magnetoresistance in Transition Metal Multilayers

Abstract

The indirect magnetic exchange coupling of magnetic moments via non-magnetic metals has attracted considerable interest over the past few decades. Much work has been carried out on systems comprised of low concentrations of magnetic atoms randomly distributed in metallic hosts, for example, Mn or Fe atoms dissolved in Cu or Au. It was found that the magnetic atoms are exchange-coupled via a spin polarization of the conduction electrons of the host metal1-3. The spin polarization has been inferred from, for example, Cu63 nuclear magnetic resonance (NMR) measurements in which satellites are observed surrounding the main NMR line3. The satellites, corresponding to successive spherical shells of Cu atoms surrounding the magnetic impurities, are shifted alternately to higher and lower magnetic resonance fields resulting from oscillations in the spin polarization of the Cu conduction electrons. For higher concentrations of magnetic impurities the oscillating spin polarization is manifested as an oscillating exchange interaction, alternating between ferromagnetic and antiferromagnetic coupling depending on the separation of the magnetic impurities. This coupling is of the well-known Ruderman-Kittel-Kasuya-Yosida (RKKY) form (see, for example,4).KeywordsBuffer LayerMolecular Beam EpitaxySpace LayerMagnetic LayerGiant MagnetoresistanceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.