High performance magnetoimpedance in FeNi/Ti nanostructured multilayers with opened magnetic flux

Abstract

Magnetic [FeNi (170 nm)/Ti (6 nm)] 3/Cu (L Cu =250 or 500 nm)/[Ti (6 nm)/FeNi (170 nm)] 3 multilayers were designed with focus on high frequency applications. They were deposited onto glass or a microfluidic system compatible flexible Ciclo Olefin Copolymer substrate and comparatively tested. A maximum sensitivity for the total impedance of 110%/Oe was obtained for a driving current frequency of 30 MHz for [FeNi/Ti] 3/Cu (L Cu = 500 nm)/[Ti/FeNi] 3 multilayers deposited onto a glass substrate and 45%/Oe for a driving current frequency of 65 MHz for the same multilayers deposited onto the flexible polymer substrate, a very promising result for applications. The possibility of using flexible substrate/[FeNi/Ti] 3/Cu/[Ti/FeNi] 3 multilayers as MI pressure-sensitive elements was also demonstrated. Copyright © 2012 American Scientific Publishers All rights reserved.