Electrodeposited cobalt films: The effect of deposition potentials on the film properties

A series of cobalt films were deposited on copper substrates at different deposition potentials between -1.0 V and -1.6 V and their properties were investigated. The proper deposition potentials were obtained from the cyclic voltammetry method. The magnetic analysis of the films showed the saturation magnetization increased and the coercivity decreased as the deposition potential increased. It was also observed that the easy axis direction of magnetization was parallel to the film plane for all films. X-ray diffraction results revealed that all films had a mixture of hexagonal close-packed (hcp) and face-centred cubic (fcc) phases, and the hcp/fcc ratio increased as the deposition potential increased. Scanning electron microscope images showed that the morphology changed from ridged grains to a smooth surface with the increase of deposition potential. The results showed that the changes in magnetic and structural properties of cobalt films were substantially depend on the variation of deposition potentials. Therefore, the change of the potentials was seen to control the properties of the films and hence their properties could be modified for desired purpose.