Influence of Different Annealing Process on the Giant Mageto-impedance Effect of FeZrBCu Films

Influence of different annealing process on the giant magneto-impedance (GMI) effect in soft magnetic alloy films of (Fe88Zr7B5)0.96Cu0.04, which were prepared by radio frequency (RF) sputtering, was studied. It is obtained that both natural and current annealing can reduce the longitudinal GMI ratio. And the longitudinal GMI ratio of the annealed films increases with the increase of annealing current, and reaches a maximum value of 17% at 800mA, while the sensitivity increase to 7%(kA/m)-1 at such annealing current (800mA). In addition, influence of the magnetic field annealing on GMI effect is discussed. It is found that both the longitudinal and transverse GMI ratios of the films after magnetic field annealed increase at different temperatures. There exists a critical temperature (250℃), at which the longitudinal GMI ration presents a single-peak with a value of 17.5%, while the transverse one presents a double-peak with a value of 17.8% at ±0.4kA/m.