Nanocrystallization kinetics and magnetic properties of the melt spun amorphous (Fe0.5Co0.5)77Si11B9Cu0.6Nb2.4 alloy

• Kinetics of crystallization in cobalt Co-Finemet alloy was investigated.
• Variable activation energy for crystallization implies a complex multi stage reaction.
• Values of scan rates used to calculate the activation energy could affect the results.

Kinetics of crystallization in an amorphous (Fe0.5Co0.5)77Si11B9Cu0.6Nb2.4 (at.%) alloy was investigated using differential scanning calorimetry (DSC). Transformed fraction as a function of temperature was obtained by accurate DSC measurement and the experimental data analyzed with Vyazovkin model-free kinetic method. Reconstructed form of the experimental kinetics model, g(α), clearly showed the crystallization mechanism do not belongs to a single model but almost follows the Avrami-Erofe’ev. Magnetic coercivity and hysteresis loss values of the annealed samples at 823 K were 7.5 A m−1 and 1.2 J m−3, compared to 17.1 A m−1 and 37.1 J m−3 for as spun samples. Magnetic measurements show the annealing reduces both coercivity and hysteresis loss at all frequencies.