中国物理B ›› 2010, Vol. 19 ›› Issue (7): 77502-077502.doi: 10.1088/1674-1056/19/7/077502

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Influence of the distance between two voltage contacts on giant magneto-impedance of Co-based amorphous wires

张树玲, 邢大伟, 孙剑飞   

  1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
  • 出版日期:2010-07-15 发布日期:2010-07-15

Influence of the distance between two voltage contacts on giant magneto-impedance of Co-based amorphous wires

Zhang Shu-Ling(张树玲), Xing Da-Wei(邢大伟), and Sun Jian-Fei(孙剑飞)   

  1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
  • Online:2010-07-15 Published:2010-07-15

摘要: The Co75 Fe4.2Si8B12Nb0.8 amorphous wires of 30 μ m in diameter are produced by melt extraction and annealing at 450 oC for 20 min in vacuum with a longitudinal or transverse field of 40 kA/m. Distances between the two voltage contacts of 6, 5, 4 and 2 mm are obtained by moving the two voltage contacts towards the centre of the sample at the same time. Results indicate that magneto-impedance response is dependent on the distance significantly. As distance decreases from 6 to 2 mm, △Z/Z reduces from 609% to 95% and giant magneto-impedance (GMI) profiles change from two-peak to single-peak. Besides, field sensitivity improves from 0.47%/(A/m) to 0.76%/(A/m) when the single-peak GMI just appears. It is therefore concluded that actual measurements can be made comparable only by taking into account the influence of distance between two voltage contacts for a magneto-impedance measurement.

Abstract: The Co75 Fe4.2Si8B12Nb0.8 amorphous wires of 30 μ m in diameter are produced by melt extraction and annealing at 450 $^\circ$C for 20 min in vacuum with a longitudinal or transverse field of 40 kA/m. Distances between the two voltage contacts of 6, 5, 4 and 2 mm are obtained by moving the two voltage contacts towards the centre of the sample at the same time. Results indicate that magneto-impedance response is dependent on the distance significantly. As distance decreases from 6 to 2 mm,  $\Delta Z/Z$ reduces from 609% to 95% and giant magneto-impedance (GMI) profiles change from two-peak to single-peak. Besides, field sensitivity improves from 0.47%/(A/m) to 0.76%/(A/m) when the single-peak GMI just appears. It is therefore concluded that actual measurements can be made comparable only by taking into account the influence of distance between two voltage contacts for a magneto-impedance measurement.

Key words: GMI effect, amorphous wire, magnetic field anneal, domain structure

中图分类号:  (Giant magnetoresistance)

  • 75.47.De
75.80.+q (Magnetomechanical effects, magnetostriction) 75.50.Kj (Amorphous and quasicrystalline magnetic materials) 81.20.-n (Methods of materials synthesis and materials processing) 81.40.Gh (Other heat and thermomechanical treatments)