Magnetic softening and giant magneto-impedance effect of Co68Fe4Ni1Si15B12

✍ Scribed by Hoque, S. Manjura ;Hakim, M. A. ;Khan, F. A.

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 577 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200521342

✦ Synopsis

Abstract

Magnetic softening and its correlation with the giant magneto‐impedance effect have been investigated for Co~68~Fe~4~Ni~1~Si~15~B~12~ subjected to different annealing temperatures. In the as‐cast condition the Curie temperature is 230 °C and the saturation magnetization is 72.3 emu/g. A very high value of initial permeability of around 59 × 10^3^ and a low value of relative loss factor of the order of 10^–6^ have been obtained for samples annealed at 420 °C for 1 h. The sensitivity of the field dependence of the giant magneto‐impedance ratio (GMIR) for this annealing temperature is higher than that for as‐cast and other annealed samples. From X‐ray diffraction and differential scanning calorimetry results it has been found that for samples annealed at 420 °C for 1 h the ribbon is in a fully amorphous state. The extraordinary soft magnetic properties at this annealing temperature are mainly due to the structural relaxation, which determines the profile of the field dependence of the GMIR. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)