Electrodeposition of Ferromagnetic FeCo and FeCoMn Alloy from Choline Chloride Based Deep Eutectic Solvent

The electrodeposition of Fe, Co, FeCo, and FeCoMn alloy films has been performed from the choline chloride/urea deep eutectic solvent without additives. The effects of solution temperature, electrolyte concentration, deposition potential, and solution agitation on deposition rate have been studied. Film composition, morphology, crystallographic structure as well as the magnetic moment and coercivity were characterized and compared against the deposition conditions. A dominant mass transport effect was observed across most of the deposition cases. A manganese underpotential deposition phenomenon occurred with the alloy deposition. An elevated temperature results in significantly faster deposition and promotes smooth film growth with limited cracking. As-deposited FeCo alloy films are found to be ferromagnetic and nanocrystalline.