Correlations between low-field microwave absorption and magnetoimpedance in Co-based amorphous ribbons

Microwave power absorption measurements at 9.4 GHz were carried out on as-cast amorphous ribbons of nominal composition Co66Fe4B12Si13Nb4Cu. Two absorptions were observed: a small signal at a low dc field (<0.01T) and another one at a high dc field (∼0.1682T). The high-field signal shows all the features corresponding to ferromagnetic resonance. The low-field absorption (LFA) signal exhibits different characteristics such as hysteresis and a minimum in power absorption at zero magnetic field. A correlation between this LFA signal and magnetoimpedance measurements showed that both electromagnetic processes are associated with the same phenomenon.

[1]  Tsuyoshi Uchiyama,et al.  Giant magneto-impedance in Co-rich amorphous wires and films , 1995 .

[2]  I. Betancourt,et al.  Giant magnetoimpedance, skin depth and domain wall dynamics , 2002 .

[3]  P. Ciureanu,et al.  High-frequency behavior of magnetically soft wires , 2002 .

[4]  K. Garcı́a,et al.  Domain wall pinning, bulging, and displacement in circumferential domains in CoFeBSi amorphous wires , 2000 .

[5]  R. Beach,et al.  Sensitive field‐ and frequency‐dependent impedance spectra of amorphous FeCoSiB wire and ribbon (invited) , 1994 .

[6]  H. Chiriac,et al.  Correlation between the magneto-impedance and ferromagnetic resonance responses in nanocrystalline microwires , 2000 .

[7]  G. Álvarez,et al.  Characteristics of the magnetosensitive non-resonant power absorption of microwave by magnetic materials , 2004 .

[8]  R. Valenzuela,et al.  Microwave absorption in Ni–Zn ferrites through the Curie transition , 2004 .

[9]  L. Kraus.  Theory of giant magneto-impedance in the planar conductor with uniaxial magnetic anisotropy , 1999 .

[10]  R. O'handley.  Modern magnetic materials , 1999 .

[11]  L. Tagirov,et al.  High-frequency magnetoresonance absorption in amorphous magnetic microwires , 2002 .

[12]  V. Zhukova,et al.  Effect of annealing under torsion stress on the field dependence of the impedance tensor in amorphous wires , 2002 .

[13]  L. Brunetti,et al.  Study of magneto impedance effect in the microwave frequency range for soft magnetic wires and microwires , 2000 .

[14]  D. J. Mapps,et al.  Field-dependent surface impedance tensor in amorphous wires with two types of magnetic anisotropy: helical and circumferential , 2001 .