Giant Magneto-Impedance Effect in As-Deposited Multilayered Amorphous Films

Giant magneto-impedance effects have been observed in as-deposited amorphous FeCuNbSiB/Cu/FeCuNbSiB and FeCuNbSiB/SiO₂/Ag/SiO₂/FeCuNbSiB multilayered films. The films were deposited onto Si substrates by radio frequency sputtering. In FeCuNbSiB/Cu/FeCuNbSiB films, maximum giant magneto-impedance ratios as large as 32% and 11% were obtained at 13MHz in the longitudinal and transverse fields, respectively. In FeCuNbSiB/SiO₂/Ag/SiO₂/ FeCuNbSiB films, the maximum giant magneto-impedance ratios were 47% and 57% at the same frequency for the two cases, which are much larger than those obtained in the annealed single layer films.