Magnetic properties of CoPt thin films obtained by electrodeposition from hexachloroplatinate solution. Composition, thickness and substrate dependence

In this paper, magnetic properties of CoPt thin films electrodeposited from an aqueous hexachloroplatinate solution at pH 5.5, in presence of saccharin as an additive, are reported. The electrodeposition was carried out on a sputtered Ru-substrate at controlled potential. X-ray diffraction measurements revealed that CoPt thin films prepared in these specific conditions crystallize in the hexagonal close packing (hcp) phase. The variations of the magnetic properties of 15-500 nm CoPt thin films are explained by taking into account the changes in the elemental composition, thickness, dynamics of the surface roughening during the early stages of deposition, and under-layer structure of the Ru-substrate. The structure and the width of the magnetic domains of electrodeposited CoPt thin films were examined by MFM and found to be thickness dependent.