Magnetoresonance study of amorphous magnetic microwires

Abstract

The Fe69Si16B10C5, Co75Si10B15, Co68Mn7Si10B15 amorphous microwires, which exhibit giant magnetoimpedance phenomenon, have been studied by the Ferromagnetic Resonance (FMR) technique in the 10-GHz frequency band. The specimens under study were metal threads about 5 mum in diameter coated with a dielectric Pyrex layer. The analysis of resonance signal parameters points out that not only demagnetizing fields but also the effect of the skin depth and/or magnetoelastic/crystalline anisotropies should be taken in account. The skip of magnetoimpedance and the effect of remanent magnetization on the resonance signal in the vicinity of the low-field area have been observed. The nonequivalence of two possible parallel orientations of microwires with respect to static magnetic field has been found. The possible reasons for the observed temperature dependencies of the resonance linewidth and position have also been discussed.