Tunable electric polarization of amorphous ferromagnetic wires at GHz frequencies for wireless sensing applications

Dhumazoda, A.; Awale, R.; Podgornaya, S.V.; Panina, L.V.; Morchenko, A.T.; Kostishin, V.G.

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Tunable electric polarization of amorphous ferromagnetic wires at GHz frequencies for wireless sensing applications

Authors

Date of publication

2016

Abstract

Wireless miniature sensors are required for a wide range of applications such as non-destructive evaluation, multifunctional materials, embedded sensors, etc. In this work, the electrical polarization in ferromagnetic microwires dependent on the wire magnetic structure is investigated with the aim of sensing applications. The wire behaves as antenna exhibiting a resonance at half wavelength condition. At the vicinity of this resonance the polarization is sensitive to all the losses including magnetic losses. The transfer mechanism is based on the magnetoimpedance effect (MI) which requires a specific magnetic structure.
In order to realize efficient tunable properties, magnetic microwires of CoFeSiB composition in amorphous state are considered. For microwave sensing applications, the magnetic structure in the outer shell of a circumferential or helical type is preferable, which can be established in Co-rich alloys with negative magnetostriction. The external magnetic field, stress and temperature can substantially modify the magnetic anisotropy, magnetization processes and high frequency impedance.
The use of metal inclusions in microwave applications is often justified by their larger electric polarisability in comparison with dielectrics. This enables a strong response even from a single inclusion. Here we demonstrate that scattering from a ferromagnetic microwire showing large MI effect at microwaves can be modulated with a low frequency magnetic field and the amplitude of this modulation near the antenna resonance can sensitively change in the presence of the external stress or temperature. The modelling is based on solving the scattering problem from a cylindrical wire with the impedance boundary conditions. The modelling results agree well with the experimental data.

Keywords

ferromagnetic microwires, antenna resonance, magnetoimpedance, electric polarizability, embedded sensors

Library reference

Dhumazoda A., Awale R., Podgornaya S.V., Panina L.V., Morchenko A.T., Kostishin V.G. Tunable electric polarization of amorphous ferromagnetic wires at GHz frequencies for wireless sensing applications // Problems of Perspective Micro- and Nanoelectronic Systems Development - 2016. Proceedings / edited by A. Stempkovsky, Moscow, IPPM RAS, 2016. Part 4. P. 215-222.

URL of paper

http://www.mes-conference.ru/data/year2016/pdf/D137.pdf