Effect of heat treatment under an external magnetic field on the soft magnetic properties in FeCo-based nanocrystalline alloys

I. Škorvánek¹ - J. Marcin¹ - J. Turċanová¹ - J. Kováċ¹ - P. Švec²

¹ Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova~47,~040~01~Košice,~Slovakia
² Institute of Physics, Slovak Academy of Sciences, Dúbravská~cesta~9,~842~28~Bratislava,~Slovakia

Abstract
We report on the effects of both longitudinal and transverse magnetic fields applied during the heat treatment on the magnetic behaviour in the Fe_44.5Co_44.5Zr₇B₄ and Fe₃₈Co₃₈Mo₈B₁₅Cu₁ nanocrystalline alloys. Sheared loops with good field linearity were achieved after annealing in a transverse magnetic field. The stronger response to the transverse field-annealing is observed for the alloys containing Zr, where the values of the induced anisotropy constant up to K_u ∼ 1250 J/m³ can be reached. A heat treatment under the longitudinal magnetic field results for the Mo-containing samples in squared hysteresis loops characterized by coercive field values in the range of 3-8 A/m. These values are superior to those previously reported for the FeCo-based nanocrystalline materials. Figs 4, Refs 8.