Supergiant magnetoimpedance effect in a glass-coated microwire LC resonator

Abstract

Supergiant magnetoimpedance (SGMI) effect was found to be present in a LC resonator consisting of a glass-coated amorphous Co83.2B3.3Si5.9Mn7.6 microwire. It is found that the form of the impedance curves as a function of applied field is highly sensitive with increasing frequency. The phase angle was also strongly found to be dependent on this field. As one approached the resonance frequency, extremely large increments of magnetoimpedance are observed. SGMI values of 400 000% are found by precise tuning of the frequency around 518.51 MHz. Accordingly, the sudden change of the phase angle, as large as 180 degrees C, evidenced the occurrence of the resonance at a given intensity of the external dc magnetic field. These phenomena can be explained in terms of a ferromagnetic resonance in an ultrasoft magnetic microwire. (C) 2006 American Institute of Physics.