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The giant magneto impedance (GMI) ratio in Co-based amorphous ribbon has greatly increased by ion irradiation. Various kinds of ion such as Xe, Ar, and N have been irradiated with energy of 100 keV by an ion implanter and ion dosage was set to 1.0x1016 ion/cm2 at a beam flux of 3.7 ìA/cm2. The GMI profiles have been measured in the samples before and after ion irradiation. The GMI ratio increased about 5 times by ion irradiation for the 0.1 MHz measuring frequency, and the change of GMI ratio by ion irradiation decreased with increasing measuring frequency. Ferromagnetic magnetic resonance (FMR) and grazing incident X-ray scattering experiments have been performed to know the effects of surface modification on magnetic properties by ion implantation. The relaxation frequencies of ion irradiated samples were decreased with increasing atomic mass of ion. The ion irradiation significantly reduces the exchange coupling field Hex, which causes the change of GMI profile after the ion irradiation. |