Magnetoimpedance of Galvanostatically Electroplated Ni-Fe Permalloy Wires

We studied the magnetoimpedance of narrow Ni-Fe Permalloy wires prepared by electrodeposition. The wires were fabricated by lithographical patterning and chemical etching of electroplated thin films. The microstructure and magnetic property of the deposit were adjusted by using an organic additive added to the electrolyte. Aspect ratio of the wires was varied between 10 and 50 by changing the length of the wire while the thickness and width were fixed. The magnetoimpedance exhibited highest value at 30 MHz and was 18-25% depending on the aspect ratio. The magnetic fields for the highest magnetoresistance increased in proportion to the frequency in the range between 1 and 100 MHz.