Giant Magnetoimpedance in Fe 89 B 4 Hf 7 Nanocrystalline Ribbons

In this work the giant magnetoimpedance effect has been found in Fe89B4Hf7 nanocrystalline ribbons. There is an optimal annealing temperature about 650°C for obtaining a large magnetoimpedance. The magnetoimpedance can reach 208% for Fe89B4Hf7 annealed at 650°C for 20min. meanwhile, it has been found that the magnetoimpedance in FeHfB shows a good thermal- heating stability, which is useful for application.