HIGH-SENSITIVITY GMR IN NIFECO CU MULTILAYERS

Magnetoresistance and magnetic hysteresis in NiFeCo/Cu soft magnetic m ultilayers with a fixed number of bilayers (six) and magnetic and spac er layer thickness but varying composition has been studied. The highe st value of the transverse GMR obtained is 6.8% in a saturation field of approximate to 40 Oe at room temperature. Very high sensitivity, ar ound 1%-2%/Oe and unconventional easy-axis hysteresis and GMR loop sha pes have been observed. The analysis of the GMR effects and the associ ated hysteretic behavior by using a model that includes biquadratic ex change coupling suggests that the samples are composed of at least two distinctively different parts.