The effect of surfactant on the structure, composition and magnetic properties of electrodeposited CoNiFe /Cu microwire

In this work, the constant current electrodeposition of a ternary CoNiFe alloy onto a copper microwire from borate baths containing three surfactant additives was compared. The additives were sodium dodecyl sulfate (SDS) as an anionic surfactant, Triton X-100 as a nonionic surfactant, and the ionic liquid (IL) 1-dodecyl-3-methylimidazolium chloride) [C12mim]Cl(as a cationic surfactant. The scanning electron microscopy of the film surfaces showed that the coatings are compact and crack-free, but morphological differences were observed. The films prepared in the IL under optimized experimental conditions showed mechanical stability, high saturation magnetization (79 emu/g), and a GMI ratio of 183.4% at 1.5 MHz, which make them promising candidates for soft magnetic applications. The effect of current density, pH, IL concentration, and metal ion concentration on the current efficiency and the alloy composition was systematically investigated. Anomalous co-deposition under a current density of 29 mA/cm2 and pH of 2.5 in the presence of 1.2 g/L IL for a deposition time of 120 min lead to 30 μm thick Co17Ni53Fe30 alloy coatings with a nanocrystalline/amorphous structure.