The GMI effect in nanocrystalline FeCuNbSiB multilayered films with a SiO2 outer layer

The giant magneto-impedance (GMI) effect in nanocrystalline FeCuNbSiB multilayered films was investigated. The multilayered films were deposited by magnetron sputter equipment with an additional SiO2 outer layer. The GMI ratio of multilayered films varied with the annealing temperature due to the changing orientation of the magnetic moments. The maximum GMI frequency of the nanocrystalline state was lower than that of the amorphous state, decreasing from 12.3 to 5.45 MHz. Ageing experiments were carried out for films with and without the insulator layer. It was seen that the GMI ratio of the multilayer film with a covered SiO2 layer was preserved well even after ageing.