Glass formation, nanocrystallisation and magnetic properties of the (Fe1–xCox)79Nb3B18 (x = 0, 0.15, 0.3, 0.45, 0.6, 0.75) metallic glasses

Abstract

Abstract The glass-forming ability (GFA), nanocrystallisation, electrical resistivity and soft magnetic properties of (Fe1-xCox)79Nb3B18 (x = 0, 0.15, 0.3, 0.45, 0.6, 0.75) glassy alloys were investigated. We found that the substitution of Fe by Co is beneficial for improving the GFA. As-spun (Fe0.55Co0.45)79Nb3B18 glassy alloys show the best GFA, along with excellent soft magnetic properties in the supercooled liquid region, with a saturation magnetisation and coercivity of 140 A · m2 · kg-1 and 19.9 A · m-1, respectively, at 60 K. With increasing Co content, the electrical resistivity initially decreases rapidly, and then fluctuates around approximately 70 ± 4 μΩ cm. With increasing the annealing temperature, the saturation magnetisation improves initially, but then decreases for the (Fe0.4Co0.6)79Nb3B18 alloy, and the coercivity does not significantly improve. These newly developed FeCoNbB multicomponent alloys exhibit appreciable GFA, good magnetic properties and low material cost, and they can serve as a promising soft magnetic material for use in industrial applications.