Structural, magnetic and magnetotransport properties of melt-spun Fe10Cu90

Melt-spun Fe10Cu90 shows a negative magnetoresistance with a nearly linear dependence on external field. The microstructure has Fe-atoms on fee-sites, corresponding to CuFe solid solution, and in bcc alpha-Fe precipitates. Ma gnetic data indicate the presence of magnetic couplings between magnetic cl usters. It is argued that both microstructures, corresponding to the two lo cations of Fe, yield a mechanism for magnetoresistance. The resistivity in zero field shows a minimum at a temperature above the magnetic freezing or ordering temperature determined as the peak of ac-susceptibility. Glassy dy namics is seen from a creep of the resistivity after cooling below the free zing temperature. A simple micromagnetic model is applied to describe the i ncrease of magnetoresistance with the amount of precipitated alpha-Fe.