A Study on Giant Magnetoimpedance Effect in VITROVAC 6025Z Micro-patterned Ribbons

¹ School of Physics and Electronic Engineering, Xinyang Normal University, Xinyang 464000, People’s Republic of China
² Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Department of Micro/Nano Electronics, School of electronic information and electrical engineering, Shanghai Jiao Tong University, Dong Chuan Road 800, Shanghai 200240, People’s Republic of China

^a Corresponding author: zhc025@sjtu.edu.cn

Abstract

In this paper, micro-patterned cobalt-based amorphous ribbons with different structures are fabricated by MEMS technology, including bonding, lithography and electroplating. The commercial amorphous ribbons (VITROVAC 6025Z) are purchased from VACUUMSHMELZE^® company. The structures of micro-patterned ribbons are designed for meander shape for different turns (one turn, two turns and three turns). The effect of external magnetic field orientation and turns on GMI ratios were studied in the frequency range of 1–40 MHz. It is found that GMI ratios almost all present negative value, which is related to the material property, namely a large coercive force. Compared with the GMI ratios obtained at transverse external magnetic field, the maximum negative GMI ratio obtained at longitudinal external magnetic field is higher. The value of −69.93% is obtained at a current frequency of 20 MHz and the magnetic field of 150 Oe. With the increase of the number of turns, the maximum positive GMI ratio increases from 0.5 % for the one turn sample to the 2.8% for the sample with three turns. The maximum nagative GMI ratio is obtained by three-turns sample. The GMI character of VITROVAC 6025Z micro-patterned ribbon is significant and the microsensor is expected to be used in biological sensing field.