Engineering of Giant Magnetoimpedance Effect of Amorphous and Nanocrystalline Microwires

A Zhukov,A Granovsky,M Churyukanova,J M Blanco,M Ipatov,V Zhukova,A Talaat

doi:10.1007/s10948-016-3645-5

Abstract

We present an overview of the factors affecting soft magnetic properties and giant magnetoimpedance (GMI) effect of thin amorphous wires. Low coercivity and high GMI effect have been observed in as-prepared Co-rich microwires. We showed that the magnetoelastic anisotropy is one of the most important parameters that determines the magnetic softness and GMI effect of glass-coated microwires, and annealing can be very effective for manipulation of the magnetic properties of amorphous ferromagnetic glass-coated microwires. After annealing of Co-rich microwires, we can observe the transformation of inclined hysteresis loops to rectangle and coexistence of fast magnetization switching and GMI effect in the same sample. We demonstrated that the switching field value of microwires can be tailored by annealing in the range from 4 to 200 A/m. On the other hand in Fe-rich FeCuNbSiB microwires after appropriate annealing, we observed considerable magnetic softening and GMI effect enhancement.

Highlights

Studies of innovative design of electromagnetic materials continue to be an important issue in microwave technology
In soft magnetic amorphous wires subjected to an external magnetic field giant magnetoimpedance (GMI) is in the range of 100% even at frequencies of few GHz [4,5,6]
The annealing even for quite short time and at low temperature leads to significant changing of the magnetic properties of both studied Co-rich microwires (Figs 2a-c)

Summary

Introduction

Studies of innovative design of electromagnetic materials continue to be an important issue in microwave technology. Composite structural materials containing periodic or random arrays of metallic wires often referred to as wire metamaterials have a strong dispersion of the dielectric function in the GHz frequency band. This behaviour could be of plasmonic or resonance type for long or short-cut wires, respectively [1,2]. Recent few years studies of glass-coated magnetic microwires exhibiting excellent sift magnetic properties and Giant magnetoimpedance effect gained considerable attention[5,6,7] These properties are related to cylindrical symmetry as well as to crystalline structure of magnetic wires. We present our recent studies of the factors affecting soft magnetic properties and giant magnetoimpedance (GMI) effect in thin amorphous wires

Experimental details

Experimental results and discussion

Tailoring of GMI effect in nanocrystalline Fe-rich microwires

Conclusions