The effects of Ag addition on the magnetic properties of an Fe87.3Zr5.9B6.5Ag0.3(at %) amorphous alloy

The magnetic properties of an Fe_87.3Zr_5.9B _6.5Ag_0.3 (at.%) amorphous alloy have been investigated as a function of annealing temperatures in order to know its potential applicability as core material for high-frequency applications. A very excellent soft magnetic material was developed. The amorphous alloy, which was annealed at T_a=400°C, exhibited very high initial permeability (μi) of 287 000 at 1 kHz and 2 mOe, very low coercivity (H_c) of 15 mOe, and low core loss (W_c) of 50 W/kg at 100 kHz and 0.1 T, respectively. It is notable that the values obtained in the present study are the best magnetic properties among various kinds of Fe-based soft amorphous materials reported up to now. The reason for the achievement of good soft magnetic properties is presumably due to the homogeneous formation of very fine α-Fe clusters of size 2-3 nm in an amorphous matrix, which can be deduced from an increase of resistivity and transmission electron microscopy (TEM) observation. The very fine α-Fe clusters embedded in an amorphous matrix, had a great influence on the reduction of magnetostriction and refinement of the magnetic domain