Structural and magnetic investigation of amorphous and gradually devitrified nanocrystalline Fe-Co-Nb-Cu-B alloys

S. N. Kane, S. S. Khinchi, Zs Gercsi, A. Gupta, L. K. Varga, F. Mazaleyrat, Y. H. Jeong

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2 Citations (Scopus)

Abstract

The structural and the magnetic properties of Fe58Co 25Nb7Cu1B9 (M83) and Fe 60Co25Nb6Cu1B8 (M85) alloys have been studied using differential scanning calorimetery (DSC), X-ray diffraction (XRD), transmission Mössbauer spectroscopy, and magnetic measurements. Thefirst crystallization peak temperatures (Tx1) of the as-cast alloys M83 and M85 are 443 and 426 °C respectively, showing that a slight variation in composition reduces the stability of the alloy against crystallization. Mössbauer and XRD measurements reveal that crystallization of the specimens starts after annealing at 370 °C, exhibiting the coexistence of a bcc crystalline phase and a residual amorphous matrix. Nanocrystallization leads to the formation of a bcc Fe-Co nanocrystalline phase consisting of 10 % Co and average grain diameters ranging between 10 - 18 nm. The obtained volumetric fractions of the nanograins for the studied specimens range between 8 - 51 %, and are in accordance with the observed Tx1 values obtained from DSC measurements. The decrease in the hyperfine field of the residual amorphous matrix (in the crystallized specimens) suggests the presence of boron in the residual amorphous matrix. Mössbauer measurements show that the higher annealing temperature enhances the order in the nanocrystalline phase. The magnetic properties of the specimens having fine nanograins (∼10 nm) lead to magnetic softening (8 A/m) whereas grain coarsening (∼18 nm) increases the coercive field values (up to 260 A/m). The observed higher coercive field values (higher than 250 A/m) for the annealed specimens are attributed to surface crystallization of the studied specimens.

Original languageEnglish
Pages (from-to)3629-3633
Number of pages5
JournalJournal of the Korean Physical Society
Volume53
Issue number6 PART 1
Publication statusPublished - Dec 1 2008

Keywords

  • DSC
  • Hysteresis measurements
  • Mössbauer spectroscopy
  • XRD

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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    Kane, S. N., Khinchi, S. S., Gercsi, Z., Gupta, A., Varga, L. K., Mazaleyrat, F., & Jeong, Y. H. (2008). Structural and magnetic investigation of amorphous and gradually devitrified nanocrystalline Fe-Co-Nb-Cu-B alloys. Journal of the Korean Physical Society, 53(6 PART 1), 3629-3633.