Crystallisation progress in Si-rich ultra-soft nanocomposite alloy fabricated by melt spinning

Ngo, D.-T., Mahmud, M.S., Nguyen, H.-H., Duong, H.-G., Nguyen, Q.-H., McVitie, S. and Chau, N. (2010) Crystallisation progress in Si-rich ultra-soft nanocomposite alloy fabricated by melt spinning. Journal of Magnetism and Magnetic Materials, 322(3), pp. 342-347. (doi:10.1016/j.jmmm.2009.09.054)

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Publisher's URL: http://dx.doi.org/10.1016/j.jmmm.2009.09.054

Abstract

The crystallisation process and the ultras-soft magnetic properties of amorphous/nanocomposite alloy Fe73.5Si17.5B5Nb3Cu1 fabricated by conventional melt-spinning technique are systematically investigated in terms of thermal analysis and in-situ measurement of magnetisation dynamics. The thermal analysis using differential scanning calorimetry showed that crystallisation from Fe-based amorphous state to α-Fe(Si) started at 535ºC. Further heating the sample leads to a transformation from the α-Fe(Si) to Fe-B phases at 670ºC. Crystallisation activation energies were determined using two models: Kissinger and John-Mehl-Avrami (JMA), which were consistent to each other with a value of 2.81 +/- 0.03 eV. High resolution transmission electron microscopy investigation revealed an ultrafine structure of α-Fe(Si) nanocrystallite with mean size of 12.5 nm embedded in an amorphous matrix. At a volume fraction of 86% of α-Fe(Si) phase, optimum soft magnetic properties were obtained with very high permeability of 110,000 and a very low coercivity of 0.015 Oe by annealing the amorphous alloy at 530ºC in 40 min.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:McVitie, Professor Stephen
Authors: Ngo, D.-T., Mahmud, M.S., Nguyen, H.-H., Duong, H.-G., Nguyen, Q.-H., McVitie, S., and Chau, N.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Journal of Magnetism and Magnetic Materials
ISSN:0304-8853

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