Preparation of NiFe films by magnetic electroplating

NiFe alloy films were prepared by magnetic electrodeposition method to replace conventional sputtering on a copper substrate. The effects of different magnetic intensities on current efficiency, throwing power and magnetic properties were investigated. Magnetic intensity played a significant role in current efficiency. When the magnetic intensity ranged from 0 to 1·0 T, the current efficiency increased from 68 to 87%. The magnetic field applied during the NiFe electroplating process would destroy the hydration state of ions in aqueous solution to increase the bath conductivity, which induced optimal throwing power. Almost all the deposited films were crystalline and formed peaks of FeNi₃ (111), FeNi₃ (200) and FeNi₃ (220). With the rise on magnetic intensity, the intensity of all three FeNi₃ peaks started to increase gradually, which induced greater crystalline. High magnetic intensity could help to obtain a smooth surface of NiFe films with small and dense particles. When the magnetic intensity ranged from 0 to 1 T, the saturation magnetisation of NiFe increased from 76 to 106 A m² kg⁻¹. However, the largest coercivity (7722 A m⁻¹) could be achieved when the magnetic intensity is equal to 0·4 T.