Giant magnetoimpedance in layered composite micro-wires for high-sensitivity magnetic sensor applications

Abstract

Currently, the design and development of novel magnetic materials with optimized properties is of relevance to study new phenomena and to use them for multifunctional applications of sensor technologies and magnetoelectronic devices. In this letter, we present a detailed investigation of giant magnetoimpedance (GMI) effect in layered magnetic microwires. A new family of layered microwire composite materials was fabricated by using rapidly quenching and coating techniques. The experimental measurements were performed using an impedance analyzer (HP 4191A) in the frequency range of 100 - 1000 MHz and a varying applied dc magnetic field within 300 Oe. Interestingly, the GMI ratio and magnetic-field sensitivity reached the largest values of 3200 and 2400%/Oe at a resonance frequency of 890.15 MHz for layered Co-rich microwire sample, respectively. These results are very ideal for the development of a new family of ultra-sensitive and high-frequency magnetic sensors. Finally, the layered composite magnetic micro-wire developed with enhanced sensitivity performance can be ideally used as sensing elements in magnetic sensor technologies. © 2009 IOP Publishing Ltd.