Tuned scattering of Electromagnetic Waves by a Finite Length Ferromagnetic Microwire

In this communication, we report a theoretical and experimental research work related to the interaction between microwaves and finite length Co-based ferromagnetic microwires exhibiting giant magnetoimpedance effect. The electric current induced along the microwire by the electromagnetic wave determines the scattering properties of the magnetic microwires. The electric current depends on the microwire impedance Z(i) as well as on the relationship between its length and the wavelength of the microwave. Numerical results describe the dependence of the induced current on the microwire magnetic permeability that determines Z(i). Furthermore, it is shown how Z(i) can be effectively tuned through the application of a bias magnetic field. Suitable combination of magnetoimpedance effect and shape resonances opens the perspective to use this system as a wireless field microsensor element as well as a sensing element for constructing codified tags.