Influence of Al and Ni on the magnetic properties of Finemet alloys

Crystallization behavior and soft magnetic properties of the FeSiBCuNbM (M=Al or Ni) Finemet alloys are investigated by X-ray diffraction, differential scanning calorimetry, hysteresis loop tracer, and vibrating sample magnetometry. The nanocrystalline alloys are prepared by annealing melt-spun amorphous ribbons at different temperatures. Results indicate that the partial substitution of Ni or Al for Nb results in the increase of saturation magnetic induction density (B-s) of the alloys. The alloys with Al or Ni show favorable combination of soft magnetic properties. The partial substitution of Ni for Nb enhances the B-s value, while Al decreases coercivity. The mechanism underlining the magnetic behavior is discussed. (C) 2010 Elsevier B.V. All rights reserved.