Preparation of meander thin-film microsensor and investigation the influence of structural parameters on the giant magnetoimpedance effect

A novel GMI-based microsensor with symmetrical meander structure has been fabricated by MEMS technology and mutual perpendicularity between longitudinal external field and easy axis was established by electroplating process for reaching a higher GMI. The GMI effects of the 3 and 6 turns sample with different Cu line width has been investigated systematically. The longitudinal frequency dependence has been given and a new frequency characteristic was observed in this paper. The experimental results show the increasing of Cu line width in appropriate range and more turns can respectively lead to greater GMI effect, the positive GMI ratio peak in 6 turns sample is nearly 4.5 times over the 3 turns sample, the peak frequency is greatly increased with the increasing of turn number, and the GMI ratio in 3 and 6 turns sample both exhibits negative maximum value when HL>50 Oe. In this work, the GMI ratio peak appears at fAC=4.8 MHz in 6 turns sample with the Cu line width of 140 μm, almost reaches 183.7 % under HL=17 Oe.