Giant magnetoimpedance in a cylindrical magnetic conductor

Abstract

A rigorous treatment of the giant magnetoimpedance (GMI) in soft magnetic wires is presented. A small-signal approximation is used for a cylindrical magnetic conductor which is saturated along its axis by a static magnetic field. The general analysis of GMI includes a discussion of the influence of different parameters on the GMI and of how the calculation can be extended to nonsaturating fields. The comparison with high frequency impedance spectra of CoFeSiB wires measured with a network analyzer, including the observation of the ferromagnetic resonance peaks, confirms that the proposed model gives a satisfactory explanation for the linear GMI effect over a broad frequency range and opens the way to more refined calculations.

Technology, Preparation and Properties of the Cast Glass-Coated Magnetic Microwires

“…The lower the NFR frequency is, the smaller the coercive force is [5,9]. In fact, low-NFR-frequency glass-coated micro-and nanowires can be used as magnetic field sensors that use the so-called asymmetric giant magneto-impedance (GMI) effect (see [17][18][19][25][26][27]). We accept that the asymmetric GMI is equivalent to the NFR with a sufficiently small natural ferromagnetic resonance frequency.…”

“…These are the functional materials that can be used as both individual materials and fillers for the composites. For example, the glass-coated microwires can possess excellent magnetic properties (Giant magnetoimpedance effect of fast magnetizxation switching) that make them very suitable as the sensing elements of devices for diverse technological applications [17,[26][27][28][29].…”

Magnetization dynamics as derived from magneto impedance measurements

“…5,6 Furthermore, it is well known that the effective transversal permeability plays a very important role in describing the whole phenomena. 7,8 In this work we study the magnetization dynamics of electrical laminations using the Z(I ac , f ,H dc ) and transverse complex permeability (I ac , f ,H dc )ϭ Јϩi Љ spectra, which are connected through the skin-depth ␦ m ϭ(2 / f ) 1/2 .…”

Magnetoimpedância Gigante em Materiais Ferromagnéticos Amorfos: Uma Breve Introdução.

“…Como já dito, há na literauta um número muito grande de trabalhos propondo soluções para tal problema uma vez que este é o procedimento comum para se tratar o problema da ressonância ferromagnética. [17]. O desenvolvimento teórico completo, ou seja, a solução das equações (10) e (11), é suficientemente trabalhoso sendo material para um longo artigo independente.…”