Giant magneto-impedance in multilayered FeSiB/Cu/FeSiB films

Multilayered FeSiB/Cu/FeSiB films were prepared by magnetron sputtering on glass substrate. The giant magneto-impedance (GMI) effect was investigated in the frequency range from 100 kHz to 40 MHz. When the magnetic field Ha is applied along the longitudinal direction of the sample, the GMI ratio increases with the increase of Ha and reaches a maximum at a certain value of Ha, then decreases to the negative GMI ratio with further increase of Ha. At a frequency of 3.2 MHz, the maximum GMI ratio is 13.50% for Ha=2400 A/m, and a larger negative GMI ratio, -9.20% is obtained for Ha=9600 A/m. The large negative GMI ratio and the maximum GMI ratio are correlated to the easy axis orientation and the dispersion of the magnetic anisotropy in the multilayered FeSiB/Cu/FeSiB films. When Ha is applied along the transverse direction, the GMI ratio is negative and a negative GMI ratio of -12.50% is obtained at 3.2 MHz for Ha=9600 A/m.