Magnetic properties of Fe90Zr7B3 ribbons studied by FMR and magnetization

Abstract The amorphous alloy Fe90Zr7B3 containing alpha-iron nanocrystallites (known commercially as NANOPERM®) is produced in ribbons by melt spinning and presents magnetic properties that allow its wide applicability in magnetic shielding, low loss RF transformers, choke coils, magnetic sensors and flux-gate magnetometers. In this work, we present a study of the effect of the annealing process realized at different temperatures on the magnetic properties of this material. Comparisons of experimental results of ferromagnetic resonance (FMR) and magnetization measurements show that the precipitation of alpha-iron phase causes the reduction of the coercive field and the in-plane magnetic anisotropy by about 70% in ribbons annealed for 1 h at temperatures between 250 and 350 °C.