Low Field Giant Magnetoimpedance Effect in TbCo6.2

摘要

Abstract We report the presence of a giant magnetoimpedance (GMI) effect and multimagnon spin resonance in polycrystalline cylindrical TbCo6.2 at low magnetic fields. The structural and magnetic characterization supported the formation of well-grained TbCo6.2. The magnetoimpedance studies in TbCo6.2 were carried out by monitoring the reactance of the inductive element with varying magnetic field intensity from 0 to 1000 G, which is interpreted through the change of surface permeability driven by penetration depth at lower frequency ranges. The ac magnetoresistance (MRac) was found to be of the order of 20, indicating a significant circular permeability change. Magnetoreactance (MX) of the order of 0.45 was observed, which is advantageous technologically for ac magnetic field sensors operating at lower frequencies. The magnetoimpedance response at high frequency was investigated using a ring resonator with a 50-Ω characteristic impedance and a fundamental resonance frequency of around 2.5 GHz. The switching of the signs of MR from negative to positive was attributed to the switching of macrospin interaction from the dipolar to the exchange kind, useful for frequency-driven magnetoresistive switches.Graphical Abstract