Influence of composition and thermal treatments on structural, magnetic and magnetotransport properties of (Fe100-xCox) 78Si9Nb3B9Cu1 alloys

S. N. Kane, Zs Gercsi, F. Mazaleyrat, L. K. Varga, M. Coisson, P. Tiberto, F. Vinai, F. Celegato, Y. H. Jeong

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Abstract

The effect of Co addition and thermal treatments on the magnetic properties and the correspond-ing changes occurring in the nanostructure and magnetoimpedance in (Fe100-xCox)78Si 9Nb3B9Cu1 with x = 0, 20, 40, 60, 70, 75, 80, 85, 90, 95 are reported. Results show that variation in the Co content affects the stability of the alloy against crystallization and that the specimen with x = 40 exhibits highest stability against crystallization. The volume fraction of the nanograins varies between 42 to 62 % and the corresponding grain diameter ranges between 9 to 13 nm. Obtained lattice parameter values suggest that the studied samples consist of bcc Co-Fe phase with Si impurities, with Co contents ranging between 50 to 74 % and Si contents ranging between 7 to 25 %. In the studied alloys, especially above x = 70, there is a tendency to form and to stabilize a Co70Fe30-like phase. The coercive force for as-cast specimens practically does not change with increasing Co content whereas the samples annealed with and without a magnetic field exhibit appreciable changes and display similar behaviours. The coercive field is systematically lower for field-annealed samples and the abrupt increase in the coercive field for alloys with x = 70 and above is attributed to the formation of a magnetically harder Co70Fe30-like phase (as compared to the Fe80Si20 phase), which were confirmed by a decrease in the lattice parameter. The maximum values of the obtained induced anisotropy constant and the anisotropy field are, respectively, 750 J/m 3 and ∼ 1250 A/m. The magnetoimpedance maximum response of the studied samples remains almost constant as a function of Co concentration for the three kinds of samples (as-cast and annealed with and without a field). However, a threefold increase in the linear range is observed for the transverse-field-annealed samples, which should increase the dynamic range of field sensors based on these new materials.

Original languageEnglish
Pages (from-to)3634-3639
Number of pages6
JournalJournal of the Korean Physical Society
Volume53
Issue number6 PART 1
Publication statusPublished - Dec 1 2008

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Keywords

  • Hysteresis measurements
  • Magnetic anisotropy
  • Magnetic-field annealing
  • Magnetoimpedance

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Kane, S. N., Gercsi, Z., Mazaleyrat, F., Varga, L. K., Coisson, M., Tiberto, P., Vinai, F., Celegato, F., & Jeong, Y. H. (2008). Influence of composition and thermal treatments on structural, magnetic and magnetotransport properties of (Fe100-xCox) 78Si9Nb3B9Cu1 alloys. Journal of the Korean Physical Society, 53(6 PART 1), 3634-3639.