Resumen

MONTIEL, H. et al. Resonant and non-resonant phenomena in measurements of microwave absorption in Co-based amorphous ribbons. Superf. vacío [online]. 2006, vol.19, n.3, pp.27-29. ISSN 1665-3521.

Microwave absorption measurements in X band (9.4 GHz,), were carried out as a function of the transverse dc magnetic field, on as-cast amorphous ribbons of composition Co₆₆Fe₄B₁₂Si₁₃Nb₄Cu prepared by melt spinning. Two different absorptions were observed: one at low dc fields (> 200 Oe) and the other one at high dc fields (< 1800 Oe). The high-field absorption has a resonant character and is associated with ferromagnetic resonance (FMR). The low-field absorption showed non-resonant features (hysteresis, non-Larmor dependence on the dc field) and can be associated with giant magnetoimpedance (GMI); it showed a good agreement when directly compared with GMI measurements. Some additional measurements were performed by rotating the sample's plane with respect to the dc field.

Palabras llave : Ferromagnetic resonance; Giant magnetoimpedance; Alloys amorphous.