Experimental study on the effect of alternating-current amplitude on GMI output stability of Co-based amorphous wires

✍ Scribed by Sun, Jian-Fei ;Liu, Jing-Shun ;Xing, Da-Wei ;Xue, Xiang

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 528 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201026676

✦ Synopsis

Abstract

The effect of alternating‐current amplitude (ACA) on the giant magnetoimpedance (GMI) output stability of Co‐based amorphous wires is studied for highly sensitive sensor applications using a precision impedance analyzer placed in a magnetically shielded space. Experimental results indicated that the “spike” phenomenon is related to the inhomogeneous distribution of local critical magnetic fields at a lower ACA, and the GMI output stability of wires can be significantly enhanced by increasing the ACA applied by more than 15 mA. The dependencies of the maximum GMI ratio [Δ__Z__/Z~0~]~max~ and magnetic field sensitivity ξ~max~ on the frequency at I~AC~ = 15 mA have been observed: [Δ__Z__/Z~0~]~max~ has a maximum value of 117.32% at 15 MHz, and the corresponding GMI peak position H~p~ tends to be the saturation of 1 Oe until 12 MHz, and ξ~max~ has the maximum of 248.34%/Oe at 12 MHz. An applied ACA of 15 mA and a working frequency of 12 MHz are therefore recommended for the circuit design of a high‐resolution magnetic‐field sensor.