Evolution of magnetic phases upon annealing in glass-coated Fe-Ni-Cu microwires

The effects of annealing on the magnetic properties of glass-coated Fe-Ni-Cu microwires have been studied. The FCC Ni-Fe particle size increases with the annealing temperature resulting in higher room temperature coercivity. When the annealing temperature is increased to 500 degreesC, a wasp-waisted hysteresis loop is observed which arises from the locking-in of the domain walls by the directional order of atoms due to diffusion under the influence of the local magnetic field. A magnetically hard glass-coated microwire with coercivity of 600 Oe is obtained after annealing at 700 degreesC for 1 h. (C) 2001 Elsevier Science B.V. All rights reserved.