Giant Magnetoimpedance Effect in Fe89Zr7-xHfxB4 Ribbon

The giant magnetoimpedance (GMI) effect in Fe89Zr7-xHfxB4 (x=0.5 or 1.0) ribbon annealed at different temperatures was investigated. The results show that some addition of hafnium to Fe-Zr-B raises the GMI effect. There is an optimum annealing temperature about 570 ℃ for obtaining large GMI behavior in Fe89Zr7-xHfxB4 (x=0.5 or 1.0) nanocrystalline ribbons. At 900 kHz, the magnetoimpedance for Fe89Zr6Hf1B4 nanocrystalline ribbon monotonically changes with applied DC field, and reaches -33.4 % at 7 162 A/m. Meanwhile, the results show that the transverse anisotropy field of Fe89Zr6Hf1B4 ribbons decreases with increasing annealing temperature from 520 ℃ to 620 ℃.