Effet des additifs organiques sur les propriétés de nanostructures de Co-Mo obtenues par déposition électrochimique

Abstract

In this work, we investigate the effect of organics additives on the electrochemical characteristics, morphological, structural and magnetic properties of Co-Mo thin films, obtained by electrodeposition on a ruthenium substrate from a sulfate bath. From the voltammetric study, the kinetic study of the deposits is optimized. Analysis of the transient currents using the theoretical model of Scharifker-Hills indicates that the nucleation mechanism of the alloy Co-Mo follows an instantaneous nucleation mechanism followed by diffusion limited growth. This mode was influenced by the nature and the concentration of the additive added to the bath. The ex-situ charactérization of the samples was determined by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and alternating magnetic field gradient magnetometers (AGFM). The surface morphology of the films changes with the nature of additive. X-ray diffraction indicates that the films crystallize in Co hcp structures. The magnetic properties of these alloys have been improved considerably by the addition of saccharin and citrates.