Soft Magnetic Wires for Sensor Applications

Abstract

First amorphous materials using rapid quenching from the liquid state were prepared nearly 50 years ago [1][2][3][4]. Development of the rapid-quenching technique allowed obtaining of new materials with metastable crystalline, amorphous, nanocrystalline, granular structures with a new combination of physical properties (mechanical, magnetic, electrochemical, etc.) and opening of new fields of research in material science, magnetism, and technology. During the next years, few rapidquenching technologies allowing preparation of different types of rapidly quenched materials have been developed. At the beginning most attention has been paid to studies of planar rapidly quenched materials: rapidly quenched ribbons produced by quenching on the drum [4][5][6].Excellent magnetic softness of amorphous materials obtained by the meltspinning technique has attracted considerable attention, making them very attractive in potential applications in recording head and microtransformer industries. Such magnetic softness originates from the absence of magnetocrystalline anisotropy in these alloys [6].Further development of the rapidly quenching fabrication techniques allowed preparation of rapidly materials with cylindrical symmetry: rapidly quenched wires [7][8][9][10]. Amorphous wires, typically around 125 μm in diameter, obtained by the so-called in-rotating-water quenching technique, have been firstly introduced in 1980.The magnetostrictive compositions exhibit rectangular hysteresis loop, while the best magnetic softness is observed for the nearly zero magnetostriction composition.

Domain-wall-assisted giant magnetoimpedance of thin-wall ferromagnetic nanotubes

“…Oersted fields, geomagnetic fields, stray fields, etc.) with a very large field sensitivity (compared to the one achievable with the giant magnetoresistance or the Hall effect) while with low requirements on working conditions of the sensor (contrary to the SQUID magnetometers) [1,2,3,4]. Though, magnetic systems of different geometries are considered to be active ingredients of the GMI-based sensors, the conducting ferromagnetic cylinder (the ferromagnetic wire) and the tube are base systems when building mathematical models of GMI.…”

Effect of Current Annealing on Domain Structure in Amorphous and Nanocrystalline FeCoMoB Microwires

“…However, disadvantage of amorphous microwires is their unstability or change of magnetic properties with time (ageing) and temperature [3]. One possible solution is to use nanocrystalline materials [4], which are prepared by controlled annealing from the amorphous precursors.…”

Domain-wall-assisted asymmetric magnetoimpedance in ferromagnetic nanostripes

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requirements on working conditions (temperature) [1][2][3]. Since it appears in ferromagnet-including electrical circuits, it is natural to search for GMI from wires or tubes.

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