Influence of gamma irradiation to the magneto-impedance ratio of the electrodeposited [NiFe/Cu]4 multilayer on meander-shape PCB substrate has been studied. The magneto-impedance ratios were measured for both un-irradiated and irradiated by gamma radiation of Co-60 with a total dose of 40 Gy. The morphological structure were done by using scanning electron microscopy (SEM). The decrease in grain size of the samples after Gamma irradiated is observed. The magnetic property modifies as consequence of the change in the microstructure samples. Within result, the magneto-impedance ratio decreases around 34.9% for irradiated sample.

The thin film of permalloy Ni80Fe20 were synthesized by electro-deposition method on PCB substrate. Then the sample irradiated by using Co-60 gamma for 20 Gy and 30 Gy. The sample were investigated by scanning electron microscopy and vibrating sample magnetometer, before and after gamma irradiation process by Co-60 gamma irradiation. The decrease in grain size with the increase of radiation dose is observed. The hysteresis curve also showed an increase in saturation magnetization with the increase of radiation dose from 708 emu/cc to 920 emu/cc. The investigation results indicate that the modification of the surface-microstructure samples by gamma irradiation change a magnetic properties in thin film permalloy Ni80Fe20.

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The magneto-impedance of the NiFe thin films is experimentally dependent on their structure. The multilayer structures of [NiFe/Cu]₄ and [NiFe/Cu]₂/Cu/[NiFe/Cu]₂ on the <em>meander structure</em> PCB Cu substrate in this study were deposited using the electrodeposition method. The frequency was varied in order to determine its effect on the magneto-impedance ratio. The results of the magneto-impedance characterization measurement showed that the maximum MI ratio in the multilayer [NiFe/Cu]₄ structure was 6.82% while in [NiFe/Cu]₂/Cu/[NiFe/Cu]₂ was 3.08% with a frequency of 100 kHz. The increase in the MI ratio in the low frequency range indicates that the MI ratio depends on the structure of the layer which is affected by the permeability of the magnetic material.

Magneto-impedance ratio of the multilayer [NiFe/Cu)]N study by the number of multilayer. The both sample films of NiFe and Cu are fabricated by electrodeposition methods on a Cu-patterned substrate. The characteristic of magneto-impedance (MI) is performed at room temperature. Magneto-impedance are modified by varying N times (2, 4, 6 and 8) and the measurements frequency. The result show that the typical symetry of the magneto-impedance curve. Then the magneto-impedance (MI) ratio increases with the increase of frequency and N number layers. The increase of the magnetic permeability should address the increase of the MI ratio. Finally, the highest magneto-impedance ratio of 13.79 is obtained for [NiFe (200)/Cu (25)]8 at frequency 100 kHz.