Influence of Demagnetization Effect on Giant Magneto Impedance of soft Ferromagnetic Metal

TL;DR

This paper investigates how the demagnetization effect influences the giant magneto-impedance (GMI) in soft ferromagnetic metals, showing that sample size and demagnetization factor significantly affect the impedance change.

Contribution

It demonstrates that the reduction in GMI effect with shorter samples is primarily due to increased demagnetization fields, highlighting the importance of sample geometry.

Findings

GMI decreases more in longer samples of Fe40Ni40B20 alloy

Demagnetization field impacts the permeability and GMI effect

Sample size influences electromagnetic screening in ferromagnetic metals

Abstract

The large change in electromagnetic impedance in ferromagnetic state of soft magnetic metals in presence of biasing magnetic field is associated with change in screening of electromagnetic field. The screening depends on the permeability of the metal. Apart from dependence on intrinsic properties of metal the permeability depends on size of the sample. It is observed that the decrease in MI in amorphous ferromagnetic ribbon of Fe40Ni40B20 alloy is large for long sample whereas corresponding change is small for short one with same biasing field. As intrinsic magnetic properties and bias field are same and the demagnetization factor increases with reduction of length of the sample the reduction of MI effect is associated with demagnetization field.