Surface Magnetoimpedance Measurements in Soft-Ferromagnetic Materials

✍ Scribed by Machado, F. L. A. ;de Araujo, A. E. P. ;Puça, A. A. ;Rodrigues, A. R. ;Rezende, S. M.

• Book ID: 101312175
• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 234 KB
• Volume: 173
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/(sici)1521-396x(199905)173:1<135::aid-pssa135>3.0.co;2-#

✦ Synopsis

We present an investigation of the surface magnetoimpedance (Z S ) in ribbons of the amorphous alloy Co 70.4 Fe 4.6 Si 15 B 10 for a broad range of frequencies (2 Â 10 3 Hz f 2 Â 10 8 Hz) and magnitudes of the ac electrical current (2 mA I ac 75 mA). The experimental data are interpreted in terms of a theoretical model valid for any value of the skin depth d, which is based on a modification of the currently used semi-infinite sample geometry model, in order to account for a broad range of d. The shape of the Z S versus applied field (H) curve is mainly determined by the variation of d with H, which can attain several orders of magnitude in the field range of the experiments (± ±3.2 Â 10 3 A/m H 3.2 Â 10 3 A/m). The results of the model fit very well the Z S versus f data using three adjustable parameters: the domain-wall relaxation time t (= 250 ns for all values of I ac used in the experiments), the transversal magnetic permeability c T (I ac ) and a resonance linewidth DH which depend on the value of H.