Electrodeposition of CoNi and CoNiP alloys in sulphamate electrolytes

Magnetic, mechanical and structural characterisation of CoNi and CoNiP electrodeposits has been performed. Bright fine-grained fcc soft-magnetic layers of CoNi have been obtained at the different current densities and bath temperatures used. Alloy formation improves the mechanical properties of coating respect to the single electrodeposited metals. The incorporation of phosphorous in CoNi deposits favoured the deposition process, which occurred at less negative potentials. Moderate phosphorous percentages were obtained but significant modifications in the structure and the magnetic properties were detected. Fcc or hcp CoNiP layers can be obtained as a function of deposition conditions, showing the hcp CoNiP the maximum coercivity values. Fcc CoNiP deposits showed the highest hardness values.