Performances of a high sensitive trilayer F/Cu/F GMI sensor

We have selected stress-annealed nanocrystalline FeSiBCuNb ribbons for trilayer ferromagnetic/copper/ferromagnetic sensors exhibiting high magneto-impedance (MI) ratio. Longitudinal MI δZ reaches 450% at 60 kHz. Measurements of responses of the GMI sensor on the small amplitude ac fields displays sensitivity of 60 V/T up to a few 100 Hz. The noise equivalent magnetic induction is equal to 13 nT/Hz+1/2, limited to the added noise from electronics.