Mössbauer and XRD investigation of electrodeposited Fe, Co and Fe-Co alloys using a gluconate plating process

Abstract

A fundamental requirement for electrodeposition systems of the 21st century is that the processes involved should be environmentally safe, as well as they should be suited to replace hazardous conventional processes thereby supporting global sustainability. Conventional plating baths contain hazardous components and facilitate the generation of non-desirable compounds. The subject of the present article is the electrodeposition of Fe, Co, and Fe-Co alloys from an electrolyte based on gluconate. Preliminary studies showed that good quality iron-cobalt alloy coatings could be obtained on copper substrates from an environmentally acceptable gluconate plating system. The gluconate bath is inexpensive, non-toxic and easily disposed of. We report the successful deposition of Fe, Co and Fe-Co alloys from a modified gluconate based electrolyte which has not been used previously to deposit these materials. The effect of process parameters, such as current density, pH and deposition time were investigated using the gluconate electrolyte at a temperature of 60 °C and a pH of 7. The phase composition, crystal structure and magnetic anisotropy of the obtained alloy deposits are correlated with the applied process parameters. The structural analysis of the deposits is mainly based on 57Fe CEMS and XRD measurements. α-Fe and Co-Fe were identified as dominant phases in Fe and Co/Fe deposits, respectively. The magnetic anisotropy of the Fe-containing deposits was found to correlate with the current density applied during deposition. The time of electrodeposition, at the same time, had little if any effect on the magnetic anisotropy of the obtained deposits. The mechanism and formation of the electrodeposits are discussed on the basis of the obtained results.