Optimization of temperature stability and sensitivity of the giant magnetoimpedance effect in meander shaped Co-based amorphous ribbon using DC-biased current for sensor application

Abstract

The influence of DC-biased current (I DC) on the longitudinal giant magnetoimpedance (GMI) effect in Co-based amorphous ribbon with a meander structure, taken from room temperature to 120 °C, has been investigated. The results show that I DC increases the temperature stability of the impedance of amorphous ribbon at 20 MHz. By deriving the expression of the transverse permeability according to a magnetization rotation model, we attributed the improved temperature stability to the combined effect of temperature and bias field H DC generated by I DC on the transverse permeability. It is also shown that I DC not only effectively inhibits the weakening of the GMI ratio at high temperature, but also significantly improves the GMI sensitivity. This will help to achieve sensitive low magnetic field measurement under large temperature fluctuation.