Soft Magnetic Properties of Electrodeposited CoNiFe Films

The soft magnetic properties of electrodeposited CoNiFe films were studied. Films composed of 30 to 50 wt% Co, 23 to 35 wt% Ni and 25 to 35 wt% Fe alloy with a high saturation flux density of more than 1.5 T exhibit low coercivities under 0.2 Oe. Film composed of 40 Co-30 Ni-30 Fe alloy, consisting primarily of an fcc phase with some bec phase material and created by annealing at 300°C, has excellent soft magnetic properties (Hc=0.06 Oe, ¿=3200, Bs=1.8 T). This bcc phase makes an appearance during the first stage of crystallization at 287°C. The structure is thermally unstable, and is due to a special feature of electrodeposition. During the annealing, H2O, H2 and CO2 were released from the film, but the patterns of generation of these gases bear little relation to the DSC pattern.