A Study on the Structural, Magnetic, and Electrical Characterization of Nickel-Iron-Cobalt Films and [FeNiCo/Cu]30 and [FeNiCo/Cu]60 Multilayers

The nickel-iron-cobalt film with soft magnetic properties, having a minimal magnetocrystalline anisotropy and magnetostriction are applied in the magnetic sensors with giant magnetoresistance effect. In this work, single layers of Ni76Fe11Co13, Ni66Fe16Co18, and Ni56Fe21Co23 were coated by the electrochemical method, and then the results of the structural, magnetic, and electrical evaluation were discussed. An increase in the concentration of nickel in the electrolyte solution caused a change in the chemical composition, and morphology of the layers, and also reduced the coercive field. The layer containing 66 atomic percent nickel showed the lowest coercivity and the highest saturation magnetization. The single layers of Ni66Fe16Co18 were deposited on the copper substrate at different times. The results indicated that increasing the deposition time and thickness firstly decreased the coercive field up to 17 Oe, and then increased it up to 45 Oe for the Ni66Fe16Co18 layer. Also, multilayers of [NiFeCo/Cu]30 and [NiFeCo/Cu]60 were synthesized. An increase in the number of layers from 30 to 60 revealed a decrease in the coercive field from 43.1 Oe to 38.4 Oe, as well as an increase in the Mr/Ms squareness ratio from 0.46 to 0.51. The magnetoresistance of [NiFeCo/Cu]60 and [NiFeCo/Cu]30 multilayers indicated an electrical resistance reduction of about 15% and 6%, respectively.