Electrodeposition of nanocrystalline cobalt, iron and coblat-iron soft magnetic films from ammonium citrate solutions

Two parallel series of electrodeposition experiments, in which cobalt and iron are codeposited from citrate-stabilized electrolytes, were conducted under various process conditions. Dibasic and tribasic ammonium citrates were used in the two series of experiments, respectively. The [CoSO4] to [FeSO4] ratio in the electrolyte was varied (1:5 to 5:1), as was the electrolyte temperature (20-60°C) Individual pure cobalt or iron was also plated under the corresponding conditions. The results indicated that plating temperature, solution composition and pH can significantly affect the electroplating behavior, and the phase composition, microstructure and magnetic properties of the plated films. Three new phases, which have not been reported previously during electrodeposition, were identified and the conditions under which each of the three phases formed are discussed. The three phases are complex bcc phase (alpha-Mn type) containing cobalt and iron (alpha'(Co, Fe)), hcp epsilon (Fe, Co) and dhcp beta (Fe, Co) phases.;Keywords: cobalt, iron, bcc (body central cube), hcp (hexagonal close packed), dhcp (double hcp), ammonium citrate, electrodeposition, phases, soft magnetic alloys, thin films, nano crystalline, pH, magnetic properties, microstructure.