한국자기학회

Hyun-Kyung Kim(Division of Materials Science & Engineering, Korea Institute of Science and Technology (KIST)), Do-Hun Kim(Division of Materials Science & Engineering, Korea Institute of Science and Technology (KIST)), De-Rac Son(Applied Optics and Electromagnetics, Hannam University), Won-Young Jeung*

(Division of Materials Science & Engineering, Korea Institute of Science and Technology (KIST))

Abstract

The magneto impedance (MI) behaviors of patterned Co₃₀Fe₃₄Ni₃₆microwire were investigated with respect to its shape variation. After preparing Co₃₀Fe₃₄Ni₃₆microwires using electrodeposition and photolithography methods, impedance measurements were conducted to compare the MI ratios of the devices with different aspect ratios. As a result, the anisotropy field and transverse permeability were found to be strongly affected by the aspect ratio of the device. The external field value at the maximum impedance and maximum sensitivity of the device was found to increase with increasing device width, which was attributed to the increased transverse anisotropy with decreasing aspect ratio. While an increase in the thickness also contributed to an increase in the MI ratio, a variation in the thickness not only increased the anisotropic field, but the variation in the MI ratio was as also affected by the skin effect. Conversely, the MI ratios of the present devices were hardly affected by variations in the length. Considering the typical aspect ratios of our devices, it was expected that the length effect would emerge when the aspect ratio was reduced to less than 10. Nevertheless, our results show that for the practical application of MI devices, the MI characteristics can be optimized by tailoring the aspect ratio of the devices.

Keywords: magneto impedance (MI); anisotropy field; skin effect; permeability

DOI: 10.4283/JMAG.2008.13.2.65

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