Magnetostriction of Fe-Co Amorphous Alloys

Longitudinal and transversal magnetostrictions of rapidly quenched amorphous alloys in (Fe_Co_x)_P_C_7 and (Fe_Co_x)_-Si_B_ systems were measured in the saturation magnetization region at room temperature. Forced magnetostrictions of these alloys were also measured in the magnetic field up to 23 kOe. A three-terminal capacitance method and a modified dilatometric method of a suspension type were employed for the measurements. The magnetostriction constant obtained by multiplying a factor 2/3 by the difference between the longitudinal and transversal magnetostrictions is zero in the alloy with x=0.94, being positive in the range of 00.94. This fact accounts for the remarkable low coercive force and high permeability of the alloy with x=0.94. The forced volume magnetostriction has been obtained to be about 23×10^ in the alloy with x=0 ; it decreases monotonically with increasing x