Giant magnetoresistance in magnetic granular Co15Cu85 alloys annealed by direct-current Joule heating

We have studied the structure and giant magnetoresistance (GMR) in the Co15Cu85 granular alloys prepared by melt-spinning and annealed by the direct-current (de) Joule heating. At T= 10 K, GMR as large as 50.0% (in a magnetic field up to 30 kOe) has been observed in a sample annealed with I = 6 A. The Joule-heated samples show higher GMR than those annealed by the conventional method. It is attributed to less content of residual Co in the Cu matrix for the de Joule-heated samples than that for the samples annealed in a furnace.164416719910