Low frequency magnetoimpedance for Co-based amorphous microwires

Abstract In this work, we present a study of the low frequency (5–13 MHz) magnetoimpedance response of amorphous microwires covered by glass. The domain wall magnetization processes active within this frequency range, namely reversible bulging of domain walls and hysteresis, are characterized through the complex inductance formalism, which allows the calculation of Cole–Cole plots. The characteristic semicircle formation of reversible bulging was observed and compared with a theoretical one based on a domain wall model for ferromagnetic wires, resulting in an excellent agreement. In addition, the wire’s magnetoimpedance response was found to be strongly dependent on the application of torsion strain as a consequence of a higher wire’s-induced anisotropy.