Amorphous alloys of (Fe_Co_x)_P_C_7 and (Fe_Co_x)_Si_B_ were prepared by rapid quenching from the melt by using two solidification techniques of centrifugal and roller types. Specimens were ribbons in form. Measurements were made of B-H hysteresis loop, effective permeability at high frequencies, longitudinal magnetostriction, electrical resistance, Vickers hardness and tensile strength. The magnetostriction is zero at a composition near x=0.94, being positive in the range of 0x>0.94. The alloy of Fe_Co_Si_B_ having a nearly zero magnetostriction exhibits the best soft magnetic properties ; the coercive force is 0.006 Oe and the maximum permeability is about 820×10^3 after annealing at 150℃ in a magnetic field. In addition, this alloy has a high effective permeability at higher frequencies up to about 100 kHz, high hardness and high tensile strength
