SOFT MAGNETIC PROPERTIES AND GIANT MAGNETOIMPEDANCE EFFECT IN MAGNETIC FIELD–DEPOSITED FeCuCrVSiB FILMS

FeCuCrVSiB soft magnetic films have been prepared using radio frequency sputtering without or with a constant magnetic field of about 72 kA/m along the longitudinal direction of film plane, and then their soft magnetic properties and giant magnetoimpedance (GMI) effects were measured. The results obtained show that the magnetic field applied during the deposition process improves significantly the soft magnetic properties of the sample. For example, its coercive force decreases from 1.080 kA/m of the non–field–deposited state to around 0.064 kA/m and its effective permeability ratio increases from 10% to 106%. The GMI effect is closely connected with this permeability ratio. The GMI effect can not almost be detected in non–field–deposited samples, while it becomes evident for field–deposited samples. The maximum values of longitudinal and transverse GMI ratios are 22% and 20% at the frequency of 13 MHz, respectively. The GMI effect in the field–deposited sample is much better than in annealed FeCuNbSiB film with the same thickness.