Studies of thermal and magnetic properties of Fe-based amorphous and nanocrystalline glass coated microwires

摘要

We studied the influence of magnetoelastic energy on properties of nanostructured glass-coated micro-wires with soft magnetic behaviour (Finemet-type microwires of Fe_(70.8)Cu_1Nb_(3.1)Si_(14.5)B_(10.6) and Fe_(73.8)Cu_1 Nb_(3.1)Si_(13)B_(9.1) compositions). The magnetoelastic energy, stored during the Finemet-type microwires fabrication, affected the hysteresis loops, coercivity and heat capacity of Finemet-type microwires. Hysteresis loops of all as-prepared microwires showed rectangular shape, typical for Fe-rich microwires. As expected, coercivity, H_c, of as-prepared microwires increases with decreasing of the ratio p defined as the ratio between the metallic nucleus-diameter, d to total microwire diameter, D. On the other hand, the change of heat capacity in T_c, ΔCp, exhibits increasing with the ratio ρ. This relationship holds for micro-wires in the as-prepared state as well as after annealing.