Abstract

A Vibrating Sample Magnetometer (VSM) and a set-up for electrical impedance measurement in magnetic field were employed to study Co<inf>30</inf>Ag<inf>70</inf> mechanical alloys with additions of 0%, 5% and 10% (mass fraction) hard magnetic SmCo<inf>5</inf>. With increasing SmCo<inf>5</inf> content, the particulate composites exhibited an increase in the remanent magnetization when the coercive field remained rather constant. The electrical impedance of each composite did not show a large variation between 10 kHz and 100 kHz but rapidly rose with the increase in frequency from around 200 kHz to 1 MHz due to the skin effect. All impedance spectra were slightly shifted when the magnetic field of 3.3 kA/m was applied. The largest difference was observed in the case of Co<inf>30</inf>Ag<inf>70</inf> without SmCo<inf>5</inf> addition. The results confirmed the relationship between the magnetic softness of materials and their electrical impedance in magnetic field. Copyright © 2013, Northwest Institute for Nonferrous Metal Research. Published by Elsevier BV. All rights reserved.