Role of artificially created defects on magnetoimpedance of Co73Fe4.5Mn0.5Nb1.0Si4.2B16.8 ribbon

• The role of demagnetization field (force anisotropy) due to artificial defects on MI effect has been investigated.
• The transverse permeability has been tuned by creating artificial defects in Co73Fe4.5Mn0.5Nb1.0Si4.2B16.8 ribbon.
• The MI(%) decreased monotonically as number of defects/holes increased on the AQ ribbon.
• MI ratio increased from 86% to 120% on joule annealing of the as-quenched ribbon.
• The double peak structure observed in MI vs. H profile can be tuned either by Joule annealing or by creating artificial defects.

Microstructure and magnetoimpedance (MI) properties of soft magnetic Co73Fe4.5Mn0.5Nb1.0Si4.2B16.8 ribbons with artificial defects have been investigated. The holes of <0.5 mm diameter were created on 5 cm long amorphous ribbon to study the role of demagnetizatizing fields on MI. The MI ratio [MI(%)] decreased by 21% for ribbon with maximum 7 holes. Present results show that the anisotropy induced by artificial defects strongly influences the MI properties. However Joule annealing at an optimum condition enables one to reduce the anisotropy developed by the defects.