Optimized giant magnetoimpedance effect in amorphous and nanocrystalline materials

Abstract

This letter reports the giant magnetoimpedance ͑GMI͒ effect and its magnetic response in optimized Co 70 Fe 5 Si 15 Nb 2.2 Cu 0.8 B 7 amorphous and Fe 71 Al 2 Si 14 B 8.5 Cu 1 Nb 3.5 nanocrystalline ribbons. At a given frequency of 5 MHz, the largest GMI ratios of 513% and 640% were observed for the Co-based amorphous and Fe-based nanocrystalline samples, respectively. More interestingly, the magnetic response reached the largest value of 144%/Oe at the frequency of 4 MHz for the Co-based amorphous sample and of 40%/Oe at the frequency of 5 MHz for the Fe-based nanocrystalline sample. This is ideal for high-frequency and high-performance GMI-based sensor applications. The skin effect model was used to interpret the obtained results of GMI in connection with the magnetic-field and frequency dependences of the longitudinal permeability.

A Study of Giant Magnetoimpedance Effect and Magnetic Response in Micro-patterned F/Ag/F Magnetic Ribbon Structures (F=Co-rich Amorphous Ribbon)

“…As shown previously in Ref. [19], the larger magnitude of μ/μ, the larger GMI effect achieved. In addition, the width of the μ/μ-H curve for Ni-containing sample and Cr-containing sample is larger compared with that for Al-containing sample.…”

“…It is also notable that the larger FWHM of the μ/μ-H curve, the lower magnetic response (field sensitivity) obtained. This is because the FWHM of the μ/μ-H curve varies proportionally to that of the Z/Z-H curve [19]. Therefore, the ξ value for the Al-containing sample is larger than that for other studied samples.…”

Surface Acoustic Wave Based Magnetic Sensors

“…With this thickness, ribbon GMI sensors operate at comparably low frequencies of hundred kHz up to a few MHz. A GMI ratio of, e.g., 640% has been obtained with a GMI ribbon made of Fe71Al2Si14B8.5Cu1Nb3.5 at 5 MHz [53].…”

A new type of longitudinally driven GMI effect of FeCo-based alloy

“…The GMI (Giant Magneto-impedance) of amorphous and nanocrystalline soft magnetic material has attracted technologists all over the world for its potential application on high-performance magnetic sensor and magnetic recording head [1][2][3][4][5] . Yabukami et al have proved the practical value of GMI by developing the GMI magnetic sensor with high sensitivity and signal-to-noise ratio [6][7][8] .…”