Magnetoresistance in glass-coated Fe–Ni–Cu microwires

Glass-coated Fe–Ni–Cu microwires were prepared by Taylor's technique. X-ray diffraction data show patterns corresponding to fcc Cu. Negative magnetoresistance has been observed, which reaches 8.15% at 77 K and 6.35% at 300 K in magnetic field of 9.0 T. There is no significant difference between I˔H and IǁH configurations. Both dc and low frequency ac (f<1 kHz) measurements exhibit essentially the same values of magnetoresistance. The observed magnetoresistance in the Fe–Ni–Cu microwires is of the same origin found in the granular giant magnetoresistance materials and is distinguishable from the giant magnetoimpedance commonly seen in soft magnetic microwires.