Magnetic microstructure and magnetoimpedance effect in NiFe/FeAlN multilayer films

The [NiFe (10 nm)/FeAlN (x nm)] multilayer films with 1 μm thickness, where x was 10 nm, 50 nm, 100 nm, and 200 nm, respectively, were fabricated by magnetron sputtering method and the magnetoimpedance (MI) ratio of these films was measured. The magnetic structure shows that the dispersion of induced anisotropy is suppressed substantially in multilayer films due to the exchange coupling between NiFe and FeAlN sublayer. Results show that the MI ratio of the multilayer film with 50 nm thickness of FeAlN sublayer has maximum MI ratio.