Giant magnetoresistance in an electrochemically synthesized regimented array of nickel quantum dots

Giant magnetoresistance (GMR) due toremotespin dependent scattering of electrons has been observed in an electrochemically synthesized structure consisting of a two-dimensional, quasi-periodic array of nickel dots (diameter ∼100 Å) overlayed with a thin copper layer. Current flows exclusively in the copper layer, but the electrons scatter from the magnetic moments on the remote, underlying nickel quantum dots. Since the scattering cross-section depends on the magnetization of the dots, the resistance of the structure can be altered with a magnetic field which then gives rise to the GMR. The magnetoresistance is about 3% of the zero-field resistance up to a magnetic flux density of 2 tesla at room temperature.