J. He et al., The influence of Co substitution on the magnetic properties and the giant magneto-impedance effect of (Fe1-xCox)(84)Zr3.5Nb3.5B8Cu1, ACT PHY C E, 8(3), 1999, pp. 208-215
The microstructure, magnetic properties and the giant magneto-impedance (GM
I) effect of the nanocrystalline (Fe1-xCox)(84)Zr3.5Nb3.5B8Cu1 ribbons have
been studied. With increasing Co concentration, the nanocrystallized grain
size and volume fraction of the alpha-Fe(Co) phase decrease under the same
annealing condition, while the coercivity H-c increases from 1.92 A/m at x
=0.0 to 30.38A/m at x=0.8. The effective permeability drops sharply with in
creasing Co concentration so that the GMI effect goes down. A value of more
than 380 % for the magneto-impedance(MI) ratio was measured at frequency f
=2.5 MHz and the sensitivity can reach 0.9% (A/m)(-1) for Fe84Zr3.5Nb3.5B8C
u1 ribbon. When a: is equal to 0.8, the MI ratio drops to about 30 % and th
e sensitivity only reaches a value of lower than 0.025% (A/m)(-1). The conc
ise analysis in theory is also expounded.