Magnetoimpedance studies on ion irradiated Co33Fe33Ni7Si7B20 ribbons

Abstract Magnetoimpedance (MI) effect was studied on amorphous Co 33 Fe 33 Ni 7 Si 7 B 20 ribbons that were irradiated with N +1 , Ar +2 and Xe +5 ions, at energy of 75 keV. The (MI) m [maximum MI in each case] values are 9.4% and 11%, 9.9% and 6.5%, the largest, for the as-quenched and N +1 , Ar +2 and Xe +5 ion irradiated ribbons respectively, at 2 MHz. The (MI) m value of the N +1 ion irradiated ribbon was observed to be the highest, due to an induced in-plane transverse magnetic anisotropy. The saturation magnetizations of the ion-irradiated ribbons are not seen to change with respect to that of the as-quenched ribbon; a small increase in the M s was observed only upon irradiation with Xe 5+ ions. The interaction between the large number of domains, with large uniaxial anisotropy led to large (MI) m values, at frequencies above 8 MHz in the Ar +2 ion irradiated ribbon.